pub mod support;

use std::{
    fs::{FileType, ReadDir, read_dir},
    path::MAIN_SEPARATOR,
    sync::Arc,
};

use nu_cli::NuCompleter;
use nu_engine::eval_block;
use nu_parser::parse;
use nu_path::{AbsolutePathBuf, expand_tilde};
use nu_protocol::{
    Config, ParseError, PipelineData, debugger::WithoutDebug, engine::StateWorkingSet,
};
use nu_std::load_standard_library;
use nu_test_support::fs;
use reedline::{Completer, Span, Suggestion};
use rstest::{fixture, rstest};
use support::{
    completions_helpers::{
        new_dotnu_engine, new_engine_helper, new_external_engine, new_partial_engine,
        new_quote_engine,
    },
    file, folder, match_suggestions, match_suggestions_by_string, new_engine,
};

// Match a list of suggestions with the content of a directory.
// This helper is for DotNutCompletion, so actually it only retrieves
// *.nu files and subdirectories.
pub fn match_dir_content_for_dotnu(dir: ReadDir, suggestions: &[Suggestion]) {
    let actual_dir_entries: Vec<_> = dir.filter_map(|c| c.ok()).collect();
    let type_name_pairs: Vec<(FileType, String)> = actual_dir_entries
        .into_iter()
        .filter_map(|t| t.file_type().ok().zip(t.file_name().into_string().ok()))
        .collect();
    let mut simple_dir_entries: Vec<&str> = type_name_pairs
        .iter()
        .filter_map(|(t, n)| {
            if t.is_dir() || n.ends_with(".nu") {
                Some(n.as_str())
            } else {
                None
            }
        })
        .collect();
    simple_dir_entries.sort();
    let mut pure_suggestions: Vec<&str> = suggestions
        .iter()
        .map(|s| {
            // The file names in suggestions contain some extra characters,
            // we clean them to compare more exactly with read_dir result.
            s.value
                .as_str()
                .trim_matches('`')
                .trim_start_matches("~")
                .trim_matches('/')
                .trim_matches('\\')
        })
        .collect();
    pure_suggestions.sort();
    assert_eq!(simple_dir_entries, pure_suggestions);
}

#[fixture]
fn completer() -> NuCompleter {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    // Add record value as example
    let record = "def tst [--mod -s] {}";
    assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

#[fixture]
fn completer_strings() -> NuCompleter {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    // Add record value as example
    let record = r#"def animals [] { ["cat", "dog", "eel" ] }
    def my-command [animal: string@animals] { print $animal }"#;
    assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

#[fixture]
fn extern_completer() -> NuCompleter {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    // Add record value as example
    let record = r#"
        def animals [] { [ "cat", "dog", "eel" ] }
        def fruits [] { [ "apple", "banana" ] }
        def options [] { [ '"first item"', '"second item"', '"third item' ] }
        extern spam [
            animal: string@animals
            fruit?: string@fruits
            ...rest: string@animals
            --foo (-f): string@animals
            -b: string@animals
            --options: string@options
        ]
    "#;
    assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

fn custom_completer_with_options(
    global_opts: &str,
    completer_opts: &str,
    completions: &[&str],
) -> NuCompleter {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = format!(
        r#"
        {}
        def comp [] {{
            {{ completions: [{}], options: {{ {} }} }}
        }}
        def my-command [arg: string@comp] {{}}"#,
        global_opts,
        completions
            .iter()
            .map(|comp| format!("'{comp}'"))
            .collect::<Vec<_>>()
            .join(", "),
        completer_opts,
    );
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

#[fixture]
fn custom_completer() -> NuCompleter {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    // Add record value as example
    let record = r#"
        let external_completer = {|spans|
            $spans
        }

        $env.config.completions.external = {
            enable: true
            max_results: 100
            completer: $external_completer
        }
    "#;
    assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

/// Use fuzzy completions but sort in alphabetical order
#[fixture]
fn fuzzy_alpha_sort_completer() -> NuCompleter {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    let config = r#"
        $env.config.completions.algorithm = "fuzzy"
        $env.config.completions.sort = "alphabetical"
    "#;
    assert!(support::merge_input(config.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    NuCompleter::new(Arc::new(engine), Arc::new(stack))
}

#[rstest]
#[case::double_dash_long_flag("tst --", None, vec!["--help", "--mod"])]
#[case::single_dash_all_flags("tst -", None, vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_after_cursor("tst -h", Some(5), vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_after_cursor_piped("tst -h | ls", Some(5), vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_in_nested_block1("somecmd | lines | each { tst - }", Some(30), vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_in_nested_block2("somecmd | lines | each { tst -}", Some(30), vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_in_incomplete_nested_block("somecmd | lines | each { tst -", None, vec!["--help", "--mod", "-h", "-s"])]
#[case::flags_in_deeply_nested_block("somecmd | lines | each { print ([each (print) (tst -)]) }", Some(52), vec!["--help", "--mod", "-h", "-s"])]
#[case::dynamic_long_flag_value("fake-cmd --flag ", None, vec!["flag:0", "flag:1", "flag:2"])]
#[case::dynamic_short_flag_value("fake-cmd arg0:0 -f ", None, vec!["flag:0", "flag:1", "flag:2"])]
#[case::dynamic_1st_positional("fake-cmd -f flag:0 ", None, vec!["arg0:0"])]
#[case::dynamic_2nd_positional("fake-cmd -f flag:0 foo --unknown ", None, vec!["arg1:0", "arg1:1"])]
fn misc_command_argument_completions(
    mut completer: NuCompleter,
    #[case] input: &str,
    #[case] pos: Option<usize>,
    #[case] expected: Vec<&str>,
) {
    let suggestions = completer.complete(input, pos.unwrap_or(input.len()));
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::command_name("my-c", None, vec!["my-command"])]
#[case::command_argument("my-command ", None, vec!["cat", "dog", "eel"])]
#[case::command_argument_after_cursor("my-command c", Some(11), vec!["cat", "dog", "eel"])]
#[case::command_argument_after_cursor_piped("my-command c | ls", Some(11), vec!["cat", "dog", "eel"])]
fn misc_custom_completions(
    mut completer_strings: NuCompleter,
    #[case] input: &str,
    #[case] pos: Option<usize>,
    #[case] expected: Vec<&str>,
) {
    let suggestions = completer_strings.complete(input, pos.unwrap_or(input.len()));
    match_suggestions(&expected, &suggestions);
}

/// $env.config should be overridden by the custom completer's options
#[test]
fn customcompletions_override_options() {
    let mut completer = custom_completer_with_options(
        r#"$env.config.completions.algorithm = "fuzzy"
           $env.config.completions.case_sensitive = false"#,
        r#"completion_algorithm: "substring",
           case_sensitive: true,
           sort: true"#,
        &["Foo Abcdef", "Abcdef", "Acd Bar"],
    );

    // sort: true should force sorting
    let expected: Vec<_> = vec!["Abcdef", "Foo Abcdef"];
    let suggestions = completer.complete("my-command Abcd", 15);
    match_suggestions(&expected, &suggestions);

    // Custom options should make case-sensitive
    let suggestions = completer.complete("my-command aBcD", 15);
    assert!(suggestions.is_empty());
}

/// $env.config should be inherited by the custom completer's options
#[test]
fn customcompletions_inherit_options() {
    let mut completer = custom_completer_with_options(
        r#"$env.config.completions.algorithm = "fuzzy"
           $env.config.completions.case_sensitive = false"#,
        "",
        &["Foo Abcdef", "Abcdef", "Acd Bar"],
    );

    // Make sure matching is fuzzy
    let suggestions = completer.complete("my-command Acd", 14);
    let expected: Vec<_> = vec!["Acd Bar", "Abcdef", "Foo Abcdef"];
    match_suggestions(&expected, &suggestions);

    // Custom options should make matching case insensitive
    let suggestions = completer.complete("my-command acd", 14);
    match_suggestions(&expected, &suggestions);
}

#[test]
fn customcompletions_no_sort() {
    let mut completer = custom_completer_with_options(
        "",
        r#"completion_algorithm: "fuzzy",
           sort: false"#,
        &["zzzfoo", "foo", "not matched", "abcfoo"],
    );
    let suggestions = completer.complete("my-command foo", 14);
    let expected_items = vec!["zzzfoo", "foo", "abcfoo"];
    let expected_inds = vec![
        Some(vec![3, 4, 5]),
        Some(vec![0, 1, 2]),
        Some(vec![3, 4, 5]),
    ];
    match_suggestions(&expected_items, &suggestions);
    assert_eq!(
        expected_inds,
        suggestions
            .iter()
            .map(|s| s.match_indices.clone())
            .collect::<Vec<_>>()
    );
}

#[test]
fn customcompletions_no_filter() {
    let mut completer = custom_completer_with_options(
        "",
        r#"filter: false"#,
        &["zzzfoo", "foo", "not matched", "abcfoo"],
    );
    let suggestions = completer.complete("my-command foo", 14);
    let expected_items = vec!["zzzfoo", "foo", "not matched", "abcfoo"];
    match_suggestions(&expected_items, &suggestions);
}

#[rstest]
#[case::happy("{ start: 1, end: 14 }", (7, 20))]
#[case::no_start("{ end: 14 }", (17, 20))]
#[case::no_end("{ start: 1 }", (7, 23))]
#[case::bad_start("{ start: 100 }", (23, 23))]
#[case::bad_end("{ end: 100 }", (17, 23))]
fn custom_completions_override_span(
    #[case] span_string: &str,
    #[case] expected_span: (usize, usize),
) {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = format!(
        r#"
        def comp [] {{ [{{ value: foobarbaz, span: {span_string} }}] }}
        def my-command [arg: string@comp] {{}}"#
    );
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "foo | my-command foobar";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["foobarbaz"], &suggestions);
    let (start, end) = expected_span;
    assert_eq!(Span::new(start, end), suggestions[0].span);
}

#[test]
fn custom_completions_override_display_value() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"
        def comp [] {
            {
                completions: [
                    { value: first, display_override: "\u{1b}[2mansi\u{1b}[3mrocks" },
                    { value: second, display_override: "sir\u{1b}[1mlancelot" },
                    { value: nonmatching, display_override: "asdf" },
                ],
                options: { completion_algorithm: "substring" }
            }
        }
        def my-command [arg: string@comp] {}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "my-command sir";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["first", "second"], &suggestions);
}

#[test]
fn custom_completions_strip_ansi_from_values() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"
        def comp [] {
            [$"\u{1b}[35mfoo", $"\u{1b}[31mbar", $"\u{1b}]8;;http://example.com\u{7}baz\u{1b}]8;;\u{7}"]
        }
        def my-command [arg: string@comp] {}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "my-command ";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["bar", "baz", "foo"], &suggestions);
}

#[test]
fn custom_completions_strip_ansi_from_record_values() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"
        def comp [] {
            [{ value: $"\u{1b}[35mmagenta_dir" }, { value: "plain_dir" }]
        }
        def my-command [arg: string@comp] {}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "my-command ";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["magenta_dir", "plain_dir"], &suggestions);
}

#[rstest]
/// Fallback to file completions if custom completer returns null
#[case::fallback(r#"
    def comp [] { null }
    def my-command [arg: string@comp] {}"#,
    "my-command test", None,
    vec![folder("test_a"), file("test_a_symlink"), folder("test_b")],
    4
)]
/// Custom function arguments mixed with subcommands
#[case::arguments_and_subcommands(r#"
    def foo [i: directory] {}
    def "foo test bar" [] {}"#,
    "foo test", None,
    vec![folder("test_a"), file("test_a_symlink"), folder("test_b"), "foo test bar".into()],
    8
)]
/// If argument type is something like int/string, complete only subcommands
#[case::arguments_vs_subcommands(r#"
    def foo [i: string] {}
    def "foo test bar" [] {}"#,
    "foo test", None,
    vec!["foo test bar".into()],
    8
)]
/// Custom function flags mixed with subcommands
#[case::flags_and_subcommands(r#"
    def foo [--test: directory] {}
    def "foo --test bar" [] {}"#,
    "foo --test", None,
    vec!["--test".into(), "foo --test bar".into()],
    10
)]
/// Flag value completion for directories
#[case::flag_value_and_subcommands(r#"
    def foo [--test: directory] {}
    def "foo --test test" [] {}"#,
    "foo --test test", None,
    vec![folder("test_a"), file("test_a_symlink"), folder("test_b"), "foo --test test".into()],
    "foo --test test".len()
)]
// Directory only
#[case::flag_value_respect_to_type(r#"
    def foo [--test: directory] {}"#,
    &format!("foo --test=directory_completion{MAIN_SEPARATOR}"), None,
    vec![folder(format!("directory_completion{MAIN_SEPARATOR}folder_inside_folder"))],
    format!("directory_completion{MAIN_SEPARATOR}").len()
)]
#[case::short_flag_value(r#"
    def foo [-t: directory] {}"#,
    &format!("foo -t directory_completion{MAIN_SEPARATOR}"), None,
    vec![folder(format!("directory_completion{MAIN_SEPARATOR}folder_inside_folder"))],
    format!("directory_completion{MAIN_SEPARATOR}").len()
)]
#[case::mixed_positional_and_flag1(r#"
    def foo [-t: directory, --path: path, pos: string, opt?: directory] {}"#,
    &format!("foo --path directory_completion{MAIN_SEPARATOR}"), None,
    vec![
        folder(format!("directory_completion{MAIN_SEPARATOR}folder_inside_folder")),
        file(format!("directory_completion{MAIN_SEPARATOR}mod.nu"))
    ],
    format!("directory_completion{MAIN_SEPARATOR}").len()
)]
#[case::mixed_positional_and_flag2(r#"
    def foo [-t: directory, --path: path, pos: string, opt?: directory] {}"#,
    &format!("foo --path bar baz directory_completion{MAIN_SEPARATOR}"), None,
    vec![folder(format!("directory_completion{MAIN_SEPARATOR}folder_inside_folder"))],
    format!("directory_completion{MAIN_SEPARATOR}").len()
)]
#[case::mixed_positional_and_flag3(r#"
    def foo [-t: directory, --path: path, pos: string, opt?: directory] {}"#,
    &format!("foo --path bar baz qux -t directory_completion{MAIN_SEPARATOR}"), None,
    vec![folder(format!("directory_completion{MAIN_SEPARATOR}folder_inside_folder"))],
    format!("directory_completion{MAIN_SEPARATOR}").len()
)]
#[case::defined_inline(
    "",
    "export def say [
    animal: string@[cat dog]
    ] { }; say ", None,
    vec!["cat".into(), "dog".into()],
    0
)]
#[case::short_flags(
    "def foo [-A, -B: string@[cat dog] ] {}",
    "foo -B ", None,
    vec!["cat".into(), "dog".into()],
    0
)]
#[case::flag_name_vs_value(
    "def foo [-A, -B: string@[cat dog] ] {}",
    "foo -B cat", Some("foo -B".len()),
    vec!["-B".into()],
    2
)]
fn command_argument_completions(
    #[case] command: &str,
    #[case] input: &str,
    #[case] pos: Option<usize>,
    #[case] expected: Vec<String>,
    #[case] span_size: usize,
) {
    let (_, _, mut engine, mut stack) = new_engine();
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // `pos` defaults to `input.len()` if set to None
    let span_end = pos.unwrap_or(input.len());
    let suggestions = completer.complete(input, span_end);
    match_suggestions_by_string(&expected, &suggestions);

    let last_res = suggestions.last().unwrap();
    assert_eq!(last_res.span.start, span_end - span_size);
    assert_eq!(last_res.span.end, span_end);
}

#[rstest]
#[case::list_flag_value1("foo --foo=", None, vec!["[f, bar]", "[f, baz]", "[foo]"])]
#[case::list_flag_value2("foo --foo=[foo", None, vec!["[foo]"])]
#[case::list_flag_value3("foo --foo [f, b", None, vec!["[f, bar]", "[f, baz]"])]
#[case::positional1("foo [f, b", None, vec!["[f, bar]", "[f, baz]"])]
#[case::positional2("foo [foo, b", Some("foo [foo".len()), vec!["[foo]"])]
#[case::positional3("foo --foo [] [foo", None, vec!["[foo]"])]
fn custom_completion_for_list_typed_argument(
    #[case] input: &str,
    #[case] pos: Option<usize>,
    #[case] expected: Vec<&str>,
) {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = /* lang=nu */ r#"
    def comp_foo [input pos] {
        ["[foo]", "[f, bar]", "[f, baz]"]
    }

    def foo [--foo: list<string>@comp_foo bar: list<string>@comp_foo] { }
    "#;

    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // `pos` defaults to `input.len()` if set to None
    let span_end = pos.unwrap_or(input.len());
    let suggestions = completer.complete(input, span_end);
    match_suggestions(&expected, &suggestions);
}

#[test]
fn list_completions_defined_inline() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = /* lang=nu */ r#"
        export def say [
          animal: string@[cat dog]
        ] { }

        say "#;
    let suggestions = completer.complete(completion_str, completion_str.len());

    // including only subcommand completions
    let expected: Vec<_> = vec!["cat", "dog"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn list_completions_extern() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = /* lang=nu */ r#"
        export extern say [
          animal: string@[cat dog]
        ]

        say "#;
    let suggestions = completer.complete(completion_str, completion_str.len());

    // including only subcommand completions
    let expected: Vec<_> = vec!["cat", "dog"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn list_completions_from_constant_and_allows_record() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = /* lang=nu */ r#"
        const animals = [
            cat
            {value: "dog"}
        ]
        export def say [
          animal: string@$animals
        ] { }

        say "#;
    let suggestions = completer.complete(completion_str, completion_str.len());

    // including only subcommand completions
    let expected: Vec<_> = vec!["cat", "dog"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn list_completions_invalid_type() {
    let (_, _, engine, _) = new_engine();

    let record = /* lang=nu */ r#"
        const animals = {cat: "meow", dog: "woof!"}
        export def say [
          animal: string@$animals
        ] { }
    "#;

    let mut working_set = StateWorkingSet::new(&engine);
    let _ = parse(&mut working_set, None, record.as_bytes(), false);

    assert!(
        working_set
            .parse_errors
            .iter()
            .any(|err| matches!(err, ParseError::OperatorUnsupportedType { .. }))
    );
}

/// External command only if starts with `^`
#[test]
fn external_commands() {
    let engine = new_external_engine();
    let mut completer = NuCompleter::new(
        Arc::new(engine),
        Arc::new(nu_protocol::engine::Stack::new()),
    );
    let completion_str = "ls; ^sleep";
    let suggestions = completer.complete(completion_str, completion_str.len());
    #[cfg(windows)]
    let expected: Vec<_> = vec!["sleep.exe"];
    #[cfg(not(windows))]
    let expected: Vec<_> = vec!["sleep"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "sleep";
    let suggestions = completer.complete(completion_str, completion_str.len());
    #[cfg(windows)]
    let expected: Vec<_> = vec!["sleep", "sleep.exe"];
    #[cfg(not(windows))]
    let expected: Vec<_> = vec!["sleep", "^sleep"];
    match_suggestions(&expected, &suggestions);

    #[cfg(windows)]
    {
        let completion_str = "scri";
        let suggestions = completer.complete(completion_str, completion_str.len());
        let expected: Vec<_> = vec!["script.ps1"];
        match_suggestions(&expected, &suggestions);
    }
}

/// Disable external commands except for those start with `^`
#[test]
fn external_commands_disabled() {
    let mut engine = new_external_engine();

    let mut config = Config::default();
    config.completions.external.enable = false;
    engine.set_config(config);

    let stack = nu_protocol::engine::Stack::new();
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "ls; ^sleep";
    let suggestions = completer.complete(completion_str, completion_str.len());
    #[cfg(windows)]
    let expected: Vec<_> = vec!["sleep.exe"];
    #[cfg(not(windows))]
    let expected: Vec<_> = vec!["sleep"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "sleep";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["sleep"];
    match_suggestions(&expected, &suggestions);
}

/// Which completes both internals and externals
#[test]
fn which_command_completions() {
    let engine = new_external_engine();
    let mut completer = NuCompleter::new(
        Arc::new(engine),
        Arc::new(nu_protocol::engine::Stack::new()),
    );
    // flags
    let completion_str = "which --all";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["--all"];
    match_suggestions(&expected, &suggestions);
    // commands
    let completion_str = "which sleep";
    let suggestions = completer.complete(completion_str, completion_str.len());
    #[cfg(windows)]
    let expected: Vec<_> = vec!["sleep", "sleep.exe"];
    #[cfg(not(windows))]
    let expected: Vec<_> = vec!["sleep", "^sleep"];
    match_suggestions(&expected, &suggestions);
}

/// Suppress completions for invalid values
#[test]
fn customcompletions_invalid() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"
        def comp [] { 123 }
        def my-command [arg: string@comp] {}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = "my-command foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    assert!(suggestions.is_empty());
}

#[test]
fn dont_use_dotnu_completions() {
    // Create a new engine
    let (_, _, engine, stack) = new_dotnu_engine();
    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // Test nested nu script
    let completion_str = "go work use `./dir_module/";
    let suggestions = completer.complete(completion_str, completion_str.len());

    // including a plaintext file
    let expected: Vec<_> = vec![
        "./dir_module/mod.nu",
        "./dir_module/plain.txt",
        "`./dir_module/sub module/`",
    ];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn dotnu_completions() {
    // Create a new engine
    let (_, _, engine, stack) = new_dotnu_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Flags should still be working
    let completion_str = "overlay use --";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(&vec!["--help", "--prefix", "--reload"], &suggestions);

    // Test nested nu script
    #[cfg(windows)]
    let completion_str = "use `.\\dir_module\\";
    #[cfg(not(windows))]
    let completion_str = "use `./dir_module/";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(
        &vec![
            #[cfg(windows)]
            ".\\dir_module\\mod.nu",
            #[cfg(windows)]
            "`.\\dir_module\\sub module\\`",
            #[cfg(not(windows))]
            "./dir_module/mod.nu",
            #[cfg(not(windows))]
            "`./dir_module/sub module/`",
        ],
        &suggestions,
    );

    // Test nested nu script, with ending '`'
    #[cfg(windows)]
    let completion_str = "use `.\\dir_module\\sub module\\`";
    #[cfg(not(windows))]
    let completion_str = "use `./dir_module/sub module/`";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(
        &vec![
            #[cfg(windows)]
            "`.\\dir_module\\sub module\\sub.nu`",
            #[cfg(not(windows))]
            "`./dir_module/sub module/sub.nu`",
        ],
        &suggestions,
    );

    let mut expected = vec![
        "asdf.nu",
        "bar.nu",
        "bat.nu",
        "baz.nu",
        "foo.nu",
        "spam.nu",
        "xyzzy.nu",
        #[cfg(windows)]
        "dir_module\\",
        #[cfg(not(windows))]
        "dir_module/",
        #[cfg(windows)]
        "lib-dir1\\",
        #[cfg(not(windows))]
        "lib-dir1/",
        #[cfg(windows)]
        "lib-dir2\\",
        #[cfg(not(windows))]
        "lib-dir2/",
        #[cfg(windows)]
        "lib-dir3\\",
        #[cfg(not(windows))]
        "lib-dir3/",
    ];

    // Test source completion
    let completion_str = "source-env ";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(&expected, &suggestions);

    // Test use completion
    expected.insert(0, "std-rfc");
    expected.insert(0, "std");
    let completion_str = "use ";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(&expected, &suggestions);

    // Test overlay use completion
    let completion_str = "overlay use ";
    let suggestions = completer.complete(completion_str, completion_str.len());

    match_suggestions(&expected, &suggestions);

    // Test special paths
    #[cfg(windows)]
    {
        let completion_str = "use \\";
        let dir_content = read_dir("\\").unwrap();
        let suggestions = completer.complete(completion_str, completion_str.len());
        match_dir_content_for_dotnu(dir_content, &suggestions);
    }

    let completion_str = "use /";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let dir_content = read_dir("/").unwrap();
    match_dir_content_for_dotnu(dir_content, &suggestions);

    let completion_str = "use ~";
    let dir_content = read_dir(expand_tilde("~")).unwrap();
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_dir_content_for_dotnu(dir_content, &suggestions);
}

// https://github.com/nushell/nushell/issues/17021
#[test]
fn module_name_completions() {
    let (_, _, mut engine, mut stack) = new_dotnu_engine();
    let code = r#"module "🤔🐘" {
       # module comment
       # another comment
    }"#;
    assert!(support::merge_input(code.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "use 🤔";

    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["🤔🐘"], &suggestions);

    assert_eq!(
        suggestions[0].description,
        Some("# module comment\n# another comment".into())
    );
}

#[test]
fn dotnu_stdlib_completions() {
    let (_, _, mut engine, stack) = new_dotnu_engine();
    assert!(load_standard_library(&mut engine).is_ok());
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // `export  use` should be recognized as command `export use`
    let completion_str = "export  use std/ass";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["std/assert"], &suggestions);

    let completion_str = "use \"std";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["std", "std-rfc"], &suggestions);
}

#[test]
fn exportable_completions() {
    let (_, _, mut engine, mut stack) = new_dotnu_engine();
    let code = r#"export module "🤔🐘" {
        export const foo = "🤔🐘";
    }"#;
    assert!(support::merge_input(code.as_bytes(), &mut engine, &mut stack).is_ok());
    assert!(load_standard_library(&mut engine).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = "use std null";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["null-device", "null_device"], &suggestions);

    let completion_str = "export use std/assert eq";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["equal"], &suggestions);

    let completion_str = "use std/assert \"not eq";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["'not equal'"], &suggestions);

    let completion_str = "use std/math [E, `TAU";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["TAU"], &suggestions);

    let completion_str = "use 🤔🐘 'foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["foo"], &suggestions);
}

#[test]
fn dotnu_completions_const_nu_lib_dirs() {
    let (_, _, engine, stack) = new_dotnu_engine();
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // file in `lib-dir1/`, set by `const NU_LIB_DIRS`
    let completion_str = "use xyzz";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["xyzzy.nu"], &suggestions);

    // file in `lib-dir2/`, set by `$env.NU_LIB_DIRS`
    let completion_str = "use asdf";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["asdf.nu"], &suggestions);

    // file in `lib-dir3/`, set by both, should not replicate
    let completion_str = "use spam";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["spam.nu"], &suggestions);

    // if `./` specified by user, file in `lib-dir*` should be ignored
    #[cfg(windows)]
    {
        let completion_str = "use .\\asdf";
        let suggestions = completer.complete(completion_str, completion_str.len());
        match_suggestions(&vec![".\\asdf.nu"], &suggestions);
    }
    let completion_str = "use ./asdf";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&vec!["./asdf.nu"], &suggestions);
}

#[test]
fn external_completer_trailing_space() {
    // https://github.com/nushell/nushell/issues/6378
    let block = "{|spans| $spans}";
    let input = "gh alias ";

    let suggestions = run_external_completion(block, input);
    match_suggestions(&vec!["gh", "alias", ""], &suggestions);
}

#[test]
fn external_completer_no_trailing_space() {
    let block = "{|spans| $spans}";
    let input = "gh alias";

    let suggestions = run_external_completion(block, input);
    assert_eq!(2, suggestions.len());
    assert_eq!("gh", suggestions.first().unwrap().value);
    assert_eq!("alias", suggestions.get(1).unwrap().value);
}

#[test]
fn external_completer_pass_flags() {
    let block = "{|spans| $spans}";
    let input = "gh api --";

    let suggestions = run_external_completion(block, input);
    assert_eq!(3, suggestions.len());
    assert_eq!("gh", suggestions.first().unwrap().value);
    assert_eq!("api", suggestions.get(1).unwrap().value);
    assert_eq!("--", suggestions.get(2).unwrap().value);
}

/// Fallback to file completions when external completer returns null
#[test]
fn external_completer_fallback() {
    let block = "{|spans| null}";
    let input = "foo test";

    let expected = [folder("test_a"), file("test_a_symlink"), folder("test_b")];
    let suggestions = run_external_completion(block, input);
    match_suggestions_by_string(&expected, &suggestions);

    // issue #15790
    let input = "foo `dir with space/`";
    let expected = vec!["`dir with space/bar baz`", "`dir with space/foo`"];
    let suggestions = run_external_completion_within_pwd(
        block,
        input,
        fs::fixtures().join("external_completions"),
    );
    match_suggestions(&expected, &suggestions);

    // issue #16712
    let input = "`dir with space/`";
    let expected = vec!["`dir with space/bar baz`", "`dir with space/foo`"];
    let suggestions = run_external_completion_within_pwd(
        block,
        input,
        fs::fixtures().join("external_completions"),
    );
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::happy("{ start: 1, end: 14 }", (7, 20))]
#[case::no_start("{ end: 14 }", (17, 20))]
#[case::no_end("{ start: 1 }", (7, 23))]
#[case::bad_start("{ start: 100 }", (23, 23))]
#[case::bad_end("{ end: 100 }", (17, 23))]
fn external_completer_override_span(
    #[case] span_string: &str,
    #[case] expected_span: (usize, usize),
) {
    let block = format!("{{|spans| [{{ value: foobarbaz, span: {span_string} }}]}}");
    let input = "foo | extcommand foobar";

    let suggestions = run_external_completion(&block, input);
    let (start, end) = expected_span;
    let expected = vec![Suggestion {
        value: "foobarbaz".to_string(),
        span: Span::new(start, end),
        ..Default::default()
    }];
    assert_eq!(expected, suggestions);
}

#[test]
fn external_completer_override_display_value() {
    let block = "{|spans| [{ value: foo, display_override: blah }] }";
    let suggestions = run_external_completion(block, "extcommand irrelevant");
    assert_eq!(1, suggestions.len());
    assert_eq!("blah", suggestions[0].display_value());
}

/// Fallback to external completions for flags of `sudo`
#[test]
fn external_completer_sudo() {
    let block = "{|spans| ['--background']}";
    let input = "sudo --back";

    let expected = vec!["--background"];
    let suggestions = run_external_completion(block, input);
    match_suggestions(&expected, &suggestions);
}

/// Suppress completions when external completer returns invalid value
#[test]
fn external_completer_invalid() {
    let block = "{|spans| 123}";
    let input = "foo ";

    let suggestions = run_external_completion(block, input);
    assert!(suggestions.is_empty());
}

#[test]
fn command_wide_completion_external() {
    let mut completer = custom_completer();

    let sample = /* lang=nu */ r#"
        @complete external
        extern "gh" []

        gh alias one two"#;

    let suggestions = completer.complete(sample, sample.len());
    let expected = vec!["gh", "alias", "one", "two"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn command_wide_completion_custom() {
    let mut completer = custom_completer();

    let sample = /* lang=nu */ r#"
        def "nu-complete foo" [spans: list] {
            $spans ++ [some more]
        }

        @complete "nu-complete foo"
        def --wrapped "foo" [...rest] {}

        foo bar baz"#;

    let suggestions = completer.complete(sample, sample.len());
    let expected = vec!["foo", "bar", "baz", "some", "more"];
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::custom(
    r#"def "nu-complete foo" [spans: list] { null }

    @complete "nu-complete foo""#
)]
#[case::external(
    r#"
    let external_completer = {|spans| null }

    $env.config.completions.external = {
        enable: true
        max_results: 100
        completer: $external_completer
    }

    @complete external"#
)]
fn command_wide_completion_fallback(#[case] code: &str) {
    // Create a new engine with PWD
    let pwd = fs::fixtures();
    let (_, _, mut engine, mut stack) = new_engine_helper(pwd.clone());

    let config_code = format!(
        r#"{code}
        def --wrapped "foo" [...rest] {{}} "#
    );
    assert!(support::merge_input(config_code.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let sample = /* lang=nu */ r#"foo bar completions"#;

    let suggestions = completer.complete(sample, sample.len());
    let expected = vec![folder("completions")];
    match_suggestions_by_string(&expected, &suggestions);
}

#[test]
fn parameter_completion_overrides_command_wide_completion() {
    let mut completer = custom_completer();

    let sample = /* lang=nu */ r#"
        def "nu-complete cmd" [spans: list] {
            [command wide completion]
        }

        def "nu-complete cmd bar" [] {
            [bar specific]
        }

        @complete "nu-complete cmd"
        def --wrapped "cmd" [
            foo: string,
            bar: string@"nu-complete cmd bar",
            ...rest
        ] {}

        cmd one "#;

    let suggestions = completer.complete(sample, sample.len());
    let expected = vec!["bar", "specific"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn command_wide_completion_flag_completion() {
    let mut completer = custom_completer();

    let sample = /* lang=nu */ r#"
        def "nu-complete cmd" [spans: list] {
            let last = $spans | last
            [command wide --with --external]
            | where $it starts-with $last
        }

        def "nu-complete cmd bar" [] {
            [bar specific]
        }

        @complete "nu-complete cmd"
        def --wrapped "cmd" [
            --switch(-s)
            --flag(-f): string
            foo: string,
            bar: string@"nu-complete cmd bar",
            ...rest
        ] {}

        cmd -"#;

    let suggestions = completer.complete(sample, sample.len());
    let expected = vec!["--flag", "--switch", "-f", "-s", "--with", "--external"];
    match_suggestions(&expected, &suggestions);

    let span = suggestions[0].span;
    assert_eq!(span.start, sample.len() - 1);
    assert_eq!(span.end, sample.len());

    // flag value completion
    let input_for_flag_value = format!("{sample}-flag ");
    let suggestions = completer.complete(&input_for_flag_value, input_for_flag_value.len());
    let expected = vec!["command", "wide", "--with", "--external"];
    match_suggestions(&expected, &suggestions);

    let span = suggestions[0].span;
    assert_eq!(span.start, input_for_flag_value.len());
    assert_eq!(span.end, input_for_flag_value.len());

    let input_for_flag_value = format!("{sample}-flag=wi");
    let suggestions = completer.complete(&input_for_flag_value, input_for_flag_value.len());
    let expected = vec!["wide"];
    match_suggestions(&expected, &suggestions);

    let span = suggestions[0].span;
    assert_eq!(span.start, input_for_flag_value.len() - 2);
    assert_eq!(span.end, input_for_flag_value.len());
}

#[test]
fn file_completions() {
    // Create a new engine
    let (dir, dir_str, engine, stack) = new_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("cp {dir_str}{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("another")),
        file(dir.join("custom_completion.nu")),
        folder(dir.join("directory_completion")),
        file(dir.join("nushell")),
        folder(dir.join("test_a")),
        file(dir.join("test_a_symlink")),
        folder(dir.join("test_b")),
        file(dir.join(".hidden_file")),
        folder(dir.join(".hidden_folder")),
    ];

    #[cfg(windows)]
    {
        let separator = '/';
        let target_dir = format!("cp {dir_str}{separator}");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for the current folder even with parts before the autocomplet
    let target_dir = format!("cp somefile.txt {dir_str}{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("another")),
        file(dir.join("custom_completion.nu")),
        folder(dir.join("directory_completion")),
        file(dir.join("nushell")),
        folder(dir.join("test_a")),
        file(dir.join("test_a_symlink")),
        folder(dir.join("test_b")),
        file(dir.join(".hidden_file")),
        folder(dir.join(".hidden_folder")),
    ];

    #[cfg(windows)]
    {
        let separator = '/';
        let target_dir = format!("cp somefile.txt {dir_str}{separator}");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for a file
    let target_dir = format!("cp {}", folder(dir.join("another")));
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [file(dir.join("another").join("newfile"))];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for hidden files
    let target_dir = format!("ls {}", file(dir.join(".hidden_folder").join(".")));
    let suggestions = completer.complete(&target_dir, target_dir.len());

    let expected_paths = [file(dir.join(".hidden_folder").join(".hidden_subfile"))];

    #[cfg(windows)]
    {
        let target_dir = format!("ls {}/.", folder(dir.join(".hidden_folder")));
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Don't suggest files as fallback when no directories match for commands expecting directories
    let suggestions = completer.complete("cd n", 4);
    let expected_paths: Vec<_> = vec![];

    // Match the results
    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn custom_command_rest_any_args_file_completions() {
    // Create a new engine
    let (dir, dir_str, mut engine, mut stack) = new_engine();
    let command = r#"def list [ ...args: any ] {}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("list {dir_str}{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("another")),
        file(dir.join("custom_completion.nu")),
        folder(dir.join("directory_completion")),
        file(dir.join("nushell")),
        folder(dir.join("test_a")),
        file(dir.join("test_a_symlink")),
        folder(dir.join("test_b")),
        file(dir.join(".hidden_file")),
        folder(dir.join(".hidden_folder")),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for the current folder even with parts before the autocomplet
    let target_dir = format!("list somefile.txt {dir_str}{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("another")),
        file(dir.join("custom_completion.nu")),
        folder(dir.join("directory_completion")),
        file(dir.join("nushell")),
        folder(dir.join("test_a")),
        file(dir.join("test_a_symlink")),
        folder(dir.join("test_b")),
        file(dir.join(".hidden_file")),
        folder(dir.join(".hidden_folder")),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for a file
    let target_dir = format!("list {}", folder(dir.join("another")));
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [file(dir.join("another").join("newfile"))];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for hidden files
    let target_dir = format!("list {}", file(dir.join(".hidden_folder").join(".")));
    let suggestions = completer.complete(&target_dir, target_dir.len());

    let expected_paths = [file(dir.join(".hidden_folder").join(".hidden_subfile"))];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[cfg(windows)]
#[test]
fn file_completions_with_mixed_separators() {
    // Create a new engine
    let (dir, dir_str, engine, stack) = new_dotnu_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Create Expected values
    let expected_paths: Vec<_> = vec![
        file(dir.join("lib-dir1").join("bar.nu")),
        file(dir.join("lib-dir1").join("baz.nu")),
        file(dir.join("lib-dir1").join("xyzzy.nu")),
    ];
    let expected_slash_paths: Vec<_> = expected_paths
        .iter()
        .map(|s| s.replace(MAIN_SEPARATOR, "/"))
        .collect();

    let target_dir = format!("ls {dir_str}/lib-dir1/");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_slash_paths, &suggestions);

    let target_dir = format!("cp {dir_str}\\lib-dir1/");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_slash_paths, &suggestions);

    let target_dir = format!("ls {dir_str}/lib-dir1\\/");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_slash_paths, &suggestions);

    let target_dir = format!("ls {dir_str}\\lib-dir1\\/");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_slash_paths, &suggestions);

    let target_dir = format!("ls {dir_str}\\lib-dir1\\");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_paths, &suggestions);

    let target_dir = format!("ls {dir_str}/lib-dir1\\");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_paths, &suggestions);

    let target_dir = format!("ls {dir_str}/lib-dir1/\\");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_paths, &suggestions);

    let target_dir = format!("ls {dir_str}\\lib-dir1/\\");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn partial_completions() {
    // Create a new engine
    let (dir, _, engine, stack) = new_partial_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for a folder's name
    let target_dir = format!("cd {}", file(dir.join("pa")));
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("partial")),
        folder(dir.join("partial-a")),
        folder(dir.join("partial-b")),
        folder(dir.join("partial-c")),
        format!("`{}`", folder(dir.join("partial-d("))),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completions for the files whose name begin with "h"
    // and are present under directories whose names begin with "pa"
    let dir_str = file(dir.join("pa").join("h"));
    let target_dir = format!("cp {dir_str}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        file(dir.join("partial").join("hello.txt")),
        folder(dir.join("partial").join("hol")),
        file(dir.join("partial-a").join("have_ext.exe")),
        file(dir.join("partial-a").join("have_ext.txt")),
        file(dir.join("partial-a").join("hello")),
        folder(dir.join("partial-a").join("hola")),
        file(dir.join("partial-b").join("hello_b")),
        file(dir.join("partial-b").join("hi_b")),
        file(dir.join("partial-c").join("hello_c")),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completion for all files under directories whose names begin with "pa"
    let dir_str = folder(dir.join("pa"));
    let target_dir = format!("ls {dir_str}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        file(dir.join("partial").join("hello.txt")),
        folder(dir.join("partial").join("hol")),
        file(dir.join("partial-a").join("anotherfile")),
        file(dir.join("partial-a").join("have_ext.exe")),
        file(dir.join("partial-a").join("have_ext.txt")),
        file(dir.join("partial-a").join("hello")),
        folder(dir.join("partial-a").join("hola")),
        file(dir.join("partial-b").join("hello_b")),
        file(dir.join("partial-b").join("hi_b")),
        file(dir.join("partial-c").join("hello_c")),
        format!("`{}`", file(dir.join("partial-d(").join(".gitkeep"))),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completion for a single file
    let dir_str = file(dir.join("fi").join("so"));
    let target_dir = format!("rm {dir_str}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [file(dir.join("final_partial").join("somefile"))];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completion where there is a sneaky `..` in the path
    let dir_str = file(dir.join("par").join("..").join("fi").join("so"));
    let target_dir = format!("rm {dir_str}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        file(
            dir.join("partial")
                .join("..")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-a")
                .join("..")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-b")
                .join("..")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-c")
                .join("..")
                .join("final_partial")
                .join("somefile"),
        ),
        format!(
            "`{}`",
            file(
                dir.join("partial-d(")
                    .join("..")
                    .join("final_partial")
                    .join("somefile"),
            )
        ),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completion for all files under directories whose names begin with "pa"
    let file_str = file(dir.join("partial-a").join("have"));
    let target_file = format!("rm {file_str}");
    let suggestions = completer.complete(&target_file, target_file.len());

    // Create the expected values
    let expected_paths = [
        file(dir.join("partial-a").join("have_ext.exe")),
        file(dir.join("partial-a").join("have_ext.txt")),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);

    // Test completion for all files under directories whose names begin with "pa"
    let file_str = file(dir.join("partial-a").join("have_ext."));
    let file_dir = format!("rm {file_str}");
    let suggestions = completer.complete(&file_dir, file_dir.len());

    // Create the expected values
    let expected_paths = [
        file(dir.join("partial-a").join("have_ext.exe")),
        file(dir.join("partial-a").join("have_ext.txt")),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn partial_completion_with_dot_expansions() {
    let (dir, _, engine, stack) = new_partial_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let dir_str = file(
        dir.join("par")
            .join("...")
            .join("par")
            .join("fi")
            .join("so"),
    );
    let target_dir = format!("rm {dir_str}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        file(
            dir.join("partial")
                .join("...")
                .join("partial_completions")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-a")
                .join("...")
                .join("partial_completions")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-b")
                .join("...")
                .join("partial_completions")
                .join("final_partial")
                .join("somefile"),
        ),
        file(
            dir.join("partial-c")
                .join("...")
                .join("partial_completions")
                .join("final_partial")
                .join("somefile"),
        ),
        format!(
            "`{}`",
            file(
                dir.join("partial-d(")
                    .join("...")
                    .join("partial_completions")
                    .join("final_partial")
                    .join("somefile"),
            )
        ),
    ];

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn command_ls_with_filecompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "ls ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions);

    let target_dir = "ls custom_completion.";
    let suggestions = completer.complete(target_dir, target_dir.len());

    let expected_paths: Vec<_> = vec!["custom_completion.nu"];

    match_suggestions(&expected_paths, &suggestions);
}

#[test]
fn command_open_with_filecompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "open ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions);

    let target_dir = "open custom_completion.";
    let suggestions = completer.complete(target_dir, target_dir.len());

    let expected_paths: Vec<_> = vec!["custom_completion.nu"];

    match_suggestions(&expected_paths, &suggestions);
}

#[test]
fn command_rm_with_globcompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "rm ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn command_cp_with_globcompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "cp ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn command_save_with_filecompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "save ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn command_touch_with_filecompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "touch ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn command_watch_with_filecompletion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "watch ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn subcommand_vs_external_completer() {
    let (_, _, mut engine, mut stack) = new_engine();
    let commands = r#"
            $env.config.completions.algorithm = "fuzzy"
            $env.config.completions.external.completer = {|spans| ["external"]}
            def foo-test-command [] {}
            def "foo-test-command bar" [] {}
            def "foo-test-command aagap bcr" [] {}
            def "food bar" [] {}
        "#;
    assert!(support::merge_input(commands.as_bytes(), &mut engine, &mut stack).is_ok());
    let mut subcommand_completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let prefix = "fod br";
    let suggestions = subcommand_completer.complete(prefix, prefix.len());
    match_suggestions(
        &vec![
            "external",
            "food bar",
            "foo-test-command bar",
            "foo-test-command aagap bcr",
        ],
        &suggestions,
    );

    let prefix = "foot bar";
    let suggestions = subcommand_completer.complete(prefix, prefix.len());
    match_suggestions(&vec!["external", "foo-test-command bar"], &suggestions);
}

#[rstest]
#[case::no_needle(
    "prefix",
    "open ",
    vec![
        ("`--help`", "--help", vec![]),
        ("`-42`", "-42", vec![]),
        ("`-inf`", "-inf", vec![]),
        ("`4.2`", "4.2", vec![]),
        ("\'[a] bc.txt\'", "[a] bc.txt", vec![]),
        ("`curly-bracket_{.txt`", "curly-bracket_{.txt", vec![]),
        ("\"double`trouble'.txt\"", "double`trouble'.txt", vec![]),
        ("`semicolon_;.txt`", "semicolon_;.txt", vec![]),
        ("'square-bracket_[.txt'", "square-bracket_[.txt", vec![]),
        ("`te st.txt`", "te st.txt", vec![]),
        ("`te#st.txt`", "te#st.txt", vec![]),
        ("`te'st.txt`", "te'st.txt", vec![]),
        ("`te(st).txt`", "te(st).txt", vec![]),
        ("`test dir/`", "test dir/", vec![])
    ],
)]
#[case::quoted_needle(
    "prefix",
    "open 'test dir/'",
    vec![
        ("`test dir/double quote`", "test dir/double quote", vec![0, 1, 2, 3, 4, 5, 6, 7]),
        ("`test dir/single quote`", "test dir/single quote", vec![0, 1, 2, 3, 4, 5, 6, 7]),
    ]
)]
#[case::same_dir(
    "fuzzy",
    "open .t",
    vec![
        ("\'[a] bc.txt\'", "[a] bc.txt", vec![6, 7]),
        ("`te st.txt`", "te st.txt", vec![5, 6]),
        ("`te#st.txt`", "te#st.txt", vec![5, 6]),
        ("`te'st.txt`", "te'st.txt", vec![5, 6]),
        ("`te(st).txt`", "te(st).txt", vec![6, 7]),
        ("`semicolon_;.txt`", "semicolon_;.txt", vec![11, 12]),
        ("`curly-bracket_{.txt`", "curly-bracket_{.txt", vec![15, 16]),
        ("\"double`trouble'.txt\"", "double`trouble'.txt", vec![15, 16]),
        ("'square-bracket_[.txt'", "square-bracket_[.txt", vec![16, 17]),
    ],
)]
#[case::within_dir(
    "fuzzy",
    "open t/q",
    vec![
        ("`test dir/double quote`", "test dir/double quote", vec![0, 16]),
        ("`test dir/single quote`", "test dir/single quote", vec![0, 16]),
    ],
)]
fn file_completion_quoted_match_indices(
    #[case] algo: &str,
    #[case] typed: &str,
    #[case] expected: Vec<(&str, &str, Vec<usize>)>,
) {
    let (_, _, mut engine, mut stack) = new_quote_engine();
    let config = format!("$env.config.completions.algorithm = '{algo}'");
    support::merge_input(config.as_bytes(), &mut engine, &mut stack).unwrap();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete(typed, typed.len());

    #[cfg(not(windows))]
    let use_forward_slashes = true;
    #[cfg(windows)]
    let use_forward_slashes = typed.contains('/');

    assert_eq!(
        expected
            .iter()
            .map(|(value, display_override, match_indices)| {
                let value = if use_forward_slashes {
                    value.to_string()
                } else {
                    value.replace("/", "\\")
                };
                let display_override = if use_forward_slashes {
                    display_override.to_string()
                } else {
                    display_override.replace("/", "\\")
                };
                (value, Some(display_override), Some(match_indices.clone()))
            })
            .collect::<Vec<_>>(),
        suggestions
            .into_iter()
            .map(|s| (s.value, s.display_override, s.match_indices))
            .collect::<Vec<_>>()
    );

    #[cfg(windows)]
    {
        if typed.contains('/') {
            let typed = typed.replace("/", "\\");
            let suggestions = completer.complete(typed.as_str(), typed.len());
            assert_eq!(
                expected
                    .into_iter()
                    .map(|(value, display_override, match_indices)| {
                        (
                            value.replace("/", "\\"),
                            Some(display_override.replace("/", "\\")),
                            Some(match_indices),
                        )
                    })
                    .collect::<Vec<_>>(),
                suggestions
                    .into_iter()
                    .map(|s| (s.value, s.display_override, s.match_indices))
                    .collect::<Vec<_>>()
            );
        }
    }
}

#[test]
fn flag_completions() {
    // Create a new engine
    let (_, _, engine, stack) = new_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // Test completions for the 'ls' flags
    let suggestions = completer.complete("ls -", 4);
    assert_eq!(18, suggestions.len());
    let expected: Vec<_> = vec![
        "--all",
        "--directory",
        "--du",
        "--full-paths",
        "--help",
        "--long",
        "--mime-type",
        "--short-names",
        "--threads",
        "-a",
        "-D",
        "-d",
        "-f",
        "-h",
        "-l",
        "-m",
        "-s",
        "-t",
    ];
    // Match results
    match_suggestions(&expected, &suggestions);

    // https://github.com/nushell/nushell/issues/16375
    let suggestions = completer.complete("table -", 7);
    assert_eq!(22, suggestions.len());
}

#[test]
fn attribute_completions() {
    // Create a new engine
    let (_, _, engine, stack) = new_engine();

    // Compile a list of built-in attribute names (without the "attr " prefix)
    let attribute_names: Vec<String> = engine
        .get_signatures_and_declids(false)
        .into_iter()
        .map(|(sig, _)| sig.name)
        .filter(|name| name.starts_with("attr "))
        .map(|name| name[5..].to_string())
        .collect();

    // Make sure we actually found some attributes so the test is valid
    assert!(attribute_names.contains(&String::from("example")));

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // Test completions for the 'ls' flags
    let suggestions = completer.complete("@", 1);

    // Match results
    match_suggestions_by_string(&attribute_names, &suggestions);
}

#[test]
fn attributable_completions() {
    // Create a new engine
    let (_, _, engine, stack) = new_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    // Test completions for the 'ls' flags
    let suggestions = completer.complete("@example; ", 10);

    let expected: Vec<_> = vec!["def", "export def", "export extern", "extern"];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Append space set to true
    assert!(suggestions[0].append_whitespace);
}

#[test]
fn folder_with_directorycompletions() {
    // Create a new engine
    let (dir, dir_str, engine, stack) = new_engine();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("cd {dir_str}{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(dir.join("another")),
        folder(dir.join("directory_completion")),
        folder(dir.join("test_a")),
        file(dir.join("test_a_symlink")),
        folder(dir.join("test_b")),
        folder(dir.join(".hidden_folder")),
    ];

    #[cfg(windows)]
    {
        let target_dir = format!("cd {dir_str}/");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn folder_with_directorycompletions_with_dots() {
    // Create a new engine
    let (dir, _, engine, stack) = new_engine();
    let dir_str = dir
        .join("directory_completion")
        .join("folder_inside_folder")
        .into_os_string()
        .into_string()
        .unwrap();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("cd {dir_str}{MAIN_SEPARATOR}..{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [folder(
        dir.join("directory_completion")
            .join("folder_inside_folder")
            .join("..")
            .join("folder_inside_folder"),
    )];

    #[cfg(windows)]
    {
        let target_dir = format!("cd {dir_str}/../");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn folder_with_directorycompletions_with_three_trailing_dots() {
    // Create a new engine
    let (dir, _, engine, stack) = new_engine();
    let dir_str = dir
        .join("directory_completion")
        .join("folder_inside_folder")
        .into_os_string()
        .into_string()
        .unwrap();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("cd {dir_str}{MAIN_SEPARATOR}...{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths = [
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join("another"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join("directory_completion"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join("test_a"),
        ),
        file(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join("test_a_symlink"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join("test_b"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("...")
                .join(".hidden_folder"),
        ),
    ];

    #[cfg(windows)]
    {
        let target_dir = format!("cd {dir_str}/.../");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn folder_with_directorycompletions_do_not_collapse_dots() {
    // Create a new engine
    let (dir, _, engine, stack) = new_engine();
    let dir_str = dir
        .join("directory_completion")
        .join("folder_inside_folder")
        .into_os_string()
        .into_string()
        .unwrap();

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for the current folder
    let target_dir = format!("cd {dir_str}{MAIN_SEPARATOR}..{MAIN_SEPARATOR}..{MAIN_SEPARATOR}");
    let suggestions = completer.complete(&target_dir, target_dir.len());

    // Create the expected values
    let expected_paths: Vec<_> = vec![
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join("another"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join("directory_completion"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join("test_a"),
        ),
        file(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join("test_a_symlink"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join("test_b"),
        ),
        folder(
            dir.join("directory_completion")
                .join("folder_inside_folder")
                .join("..")
                .join("..")
                .join(".hidden_folder"),
        ),
    ];

    #[cfg(windows)]
    {
        let target_dir = format!("cd {dir_str}/../../");
        let slash_suggestions = completer.complete(&target_dir, target_dir.len());

        let expected_slash_paths: Vec<_> = expected_paths
            .iter()
            .map(|s| s.replace('\\', "/"))
            .collect();

        match_suggestions_by_string(&expected_slash_paths, &slash_suggestions);
    }

    // Match the results
    match_suggestions_by_string(&expected_paths, &suggestions);
}

#[test]
fn variables_completions() {
    // Create a new engine
    let (_, _, mut engine, mut stack) = new_engine();

    // Add record value as example
    let record = "let actor = { name: 'Tom Hardy', age: 44 }";
    assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack).is_ok());

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Test completions for $nu
    let suggestions = completer.complete("$nu.", 4);

    assert_eq!(21, suggestions.len());

    let expected: Vec<_> = vec![
        "cache-dir",
        "config-path",
        "current-exe",
        "data-dir",
        "default-config-dir",
        "env-path",
        "history-enabled",
        "history-path",
        "home-dir",
        "is-interactive",
        "is-login",
        "is-lsp",
        "is-mcp",
        "loginshell-path",
        "os-info",
        "pid",
        "plugin-path",
        "startup-time",
        "temp-dir",
        "user-autoload-dirs",
        "vendor-autoload-dirs",
    ];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for $nu.h (filter)
    let suggestions = completer.complete("$nu.h", 5);

    assert_eq!(3, suggestions.len());

    let expected: Vec<_> = vec!["history-enabled", "history-path", "home-dir"];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for $nu.os-info
    let suggestions = completer.complete("$nu.os-info.", 12);
    assert_eq!(4, suggestions.len());
    let expected: Vec<_> = vec!["arch", "family", "kernel_version", "name"];
    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for custom var
    let suggestions = completer.complete("$actor.", 7);

    assert_eq!(2, suggestions.len());

    let expected: Vec<_> = vec!["age", "name"];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for custom var (filtering)
    let suggestions = completer.complete("$actor.n", 8);

    assert_eq!(1, suggestions.len());

    let expected: Vec<_> = vec!["name"];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for $env
    let suggestions = completer.complete("$env.", 5);

    assert_eq!(3, suggestions.len());

    #[cfg(windows)]
    let expected: Vec<_> = vec!["Path", "PWD", "TEST"];
    #[cfg(not(windows))]
    let expected: Vec<_> = vec!["PATH", "PWD", "TEST"];

    // Match results
    match_suggestions(&expected, &suggestions);

    // Test completions for $env
    let suggestions = completer.complete("$env.T", 6);

    assert_eq!(1, suggestions.len());

    let expected: Vec<_> = vec!["TEST"];

    // Match results
    match_suggestions(&expected, &suggestions);

    let suggestions = completer.complete("$", 1);
    let expected: Vec<_> = vec!["$actor", "$env", "$in", "$nu"];

    match_suggestions(&expected, &suggestions);
}

#[test]
fn local_variable_completion() {
    let (_, _, engine, stack) = new_engine();
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let completion_str = "def test [foo?: string, --foo1: bool, ...foo2] { let foo3 = true; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());

    // https://github.com/nushell/nushell/issues/15291
    let expected: Vec<_> = vec!["$foo", "$foo1", "$foo2", "$foo3"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "if true { let foo = true; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["$foo"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "if true {let foo1 = 1} else {let foo = true; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["$foo"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "for foo in [1] { let foo1 = true; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["$foo", "$foo1"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "for foo in [1] { let foo1 = true }; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    assert!(suggestions.is_empty());

    let completion_str = "(let foo = true; $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["$foo"];
    match_suggestions(&expected, &suggestions);

    let completion_str = "match {a: {b: 3}} {{a: {b: $foo}} => $foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["$foo"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn unlet_variable_current_stack_not_in_completions() {
    // Test that variables deleted with `unlet` in the current stack
    // are not available for tab completion
    let (_, _, mut engine, mut stack) = new_engine();

    // Define a variable
    let command = b"let myvar = 123";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Verify myvar IS available before unlet
    let mut completer = NuCompleter::new(Arc::new(engine.clone()), Arc::new(stack.clone()));
    let suggestions = completer.complete("$my", 3);
    assert!(
        suggestions.iter().any(|s| s.value == "$myvar"),
        "Expected $myvar to be in completions before unlet"
    );

    // Unlet the variable
    let command = b"unlet $myvar";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Verify myvar is NOT available after unlet
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let suggestions = completer.complete("$my", 3);
    assert!(
        !suggestions.iter().any(|s| s.value == "$myvar"),
        "Expected $myvar to NOT be in completions after unlet"
    );
}

#[test]
fn unlet_variable_parent_stack_not_in_completions() {
    use nu_protocol::engine::Stack;

    // Test that variables deleted with `unlet` in the parent stack
    // are not available for tab completion in a child stack
    let (_, _, mut engine, mut stack) = new_engine();

    // Define a variable in the parent stack
    let command = b"let myvar = 123";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Unlet the variable (this adds the var_id to stack.deletions)
    let command = b"unlet $myvar";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Create a child stack from the parent
    let child_stack = Stack::with_parent(Arc::new(stack));

    // Verify myvar is NOT available in child stack completions
    // (the parent's deletions should be propagated via parent_deletions check)
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(child_stack));
    let suggestions = completer.complete("$my", 3);
    assert!(
        !suggestions.iter().any(|s| s.value == "$myvar"),
        "Expected $myvar to NOT be in completions in child stack after parent unlet"
    );
}

#[test]
fn unlet_variable_grandparent_stack_not_in_completions() {
    use nu_protocol::engine::Stack;

    // Test that variables deleted with `unlet` in a grandparent stack
    // are not available for tab completion in a grandchild stack
    let (_, _, mut engine, mut stack) = new_engine();

    // Define a variable in the grandparent stack
    let command = b"let myvar = 123";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Unlet the variable in grandparent
    let command = b"unlet $myvar";
    assert!(support::merge_input(command, &mut engine, &mut stack).is_ok());

    // Create a child stack (parent level)
    let child_stack = Stack::with_parent(Arc::new(stack));

    // Create a grandchild stack
    let grandchild_stack = Stack::with_parent(Arc::new(child_stack));

    // Verify myvar is NOT available in grandchild stack completions
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(grandchild_stack));
    let suggestions = completer.complete("$my", 3);
    assert!(
        !suggestions.iter().any(|s| s.value == "$myvar"),
        "Expected $myvar to NOT be in completions in grandchild stack after grandparent unlet"
    );
}

#[rstest]
#[case("$foo.")]
#[case("$foo.a.1.")]
#[case("($foo).")]
#[case("$bar.")]
#[case("$bar.a.1.")]
#[case("{a: [1 {a: 2}]}.a.1.")]
fn record_cell_path_completions(#[case] input: &str) {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"let foo = {a: [1 {a: 2}]}; const bar = {a: [1 {a: 2}]}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete(input, input.len());
    let expected = ["a"].into();
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case("$foo.", ["a"].into())]
#[case("$foo.a.", ["b"].into())]
#[case("($foo).", ["a"].into())]
#[case("($foo).a.", ["b"].into())]
#[case("$bar.", ["a", "b"].into())]
#[case("($bar).", ["a", "b"].into())]
fn table_cell_path_completions(#[case] input: &str, #[case] expected: Vec<&str>) {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"let foo = [{a:{b:1}}, {a:{b:2}}]; const bar = [[a b]; [1 2]]"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete(input, input.len());
    match_suggestions(&expected, &suggestions);
}

#[test]
fn quoted_cell_path_completions() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"let foo = {'foo bar':1 'foo\\"bar"': 1 '.': 1 '|': 1 1: 1 "": 1}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let expected: Vec<_> = vec![
        "\"\"",
        "\".\"",
        "\"1\"",
        "\"foo bar\"",
        "\"foo\\\\\\\\\\\"bar\\\"\"",
        "\"|\"",
    ];
    let completion_str = "$foo.";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&expected, &suggestions);

    let expected: Vec<_> = vec!["\"foo bar\"", "\"foo\\\\\\\\\\\"bar\\\"\""];
    let completion_str = "$foo.`foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&expected, &suggestions);

    let completion_str = "$foo.foo";
    let suggestions = completer.complete(completion_str, completion_str.len());
    match_suggestions(&expected, &suggestions);
}

#[test]
fn alias_of_command_and_flags() {
    let (_, _, mut engine, mut stack) = new_engine();

    // Create an alias
    let alias = r#"alias ll = ls -l"#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete("ll t", 4);
    #[cfg(windows)]
    let expected_paths: Vec<_> = vec!["test_a\\", "test_a_symlink", "test_b\\"];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec!["test_a/", "test_a_symlink", "test_b/"];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn alias_of_basic_command() {
    let (_, _, mut engine, mut stack) = new_engine();

    // Create an alias
    let alias = r#"alias ll = ls "#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete("ll t", 4);
    #[cfg(windows)]
    let expected_paths: Vec<_> = vec!["test_a\\", "test_a_symlink", "test_b\\"];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec!["test_a/", "test_a_symlink", "test_b/"];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn alias_of_another_alias() {
    let (_, _, mut engine, mut stack) = new_engine();

    // Create an alias
    let alias = r#"alias ll = ls -la"#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());
    // Create the second alias
    let alias = r#"alias lf = ll -f"#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete("lf t", 4);
    #[cfg(windows)]
    let expected_paths: Vec<_> = vec!["test_a\\", "test_a_symlink", "test_b\\"];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec!["test_a/", "test_a_symlink", "test_b/"];

    match_suggestions(&expected_paths, &suggestions)
}

fn run_external_completion_within_pwd(
    completer: &str,
    input: &str,
    pwd: AbsolutePathBuf,
) -> Vec<Suggestion> {
    let completer = format!("$env.config.completions.external.completer = {completer}");

    // Create a new engine
    let (_, _, mut engine_state, mut stack) = new_engine_helper(pwd);
    let (block, delta) = {
        let mut working_set = StateWorkingSet::new(&engine_state);
        let block = parse(&mut working_set, None, completer.as_bytes(), false);
        assert!(working_set.parse_errors.is_empty());

        (block, working_set.render())
    };

    assert!(engine_state.merge_delta(delta).is_ok());

    assert!(
        eval_block::<WithoutDebug>(&engine_state, &mut stack, &block, PipelineData::empty())
            .is_ok()
    );

    // Merge environment into the permanent state
    assert!(engine_state.merge_env(&mut stack).is_ok());

    // Instantiate a new completer
    let mut completer = NuCompleter::new(Arc::new(engine_state), Arc::new(stack));

    completer.complete(input, input.len())
}

fn run_external_completion(completer: &str, input: &str) -> Vec<Suggestion> {
    run_external_completion_within_pwd(completer, input, fs::fixtures().join("completions"))
}

#[test]
fn unknown_command_completion() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let target_dir = "thiscommanddoesnotexist ";
    let suggestions = completer.complete(target_dir, target_dir.len());

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions)
}

#[test]
fn filecompletions_triggers_after_cursor() {
    let (_, _, engine, stack) = new_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let suggestions = completer.complete("cp   test_c", 3);

    #[cfg(windows)]
    let expected_paths: Vec<_> = vec![
        "another\\",
        "custom_completion.nu",
        "directory_completion\\",
        "nushell",
        "test_a\\",
        "test_a_symlink",
        "test_b\\",
        ".hidden_file",
        ".hidden_folder\\",
    ];
    #[cfg(not(windows))]
    let expected_paths: Vec<_> = vec![
        "another/",
        "custom_completion.nu",
        "directory_completion/",
        "nushell",
        "test_a/",
        "test_a_symlink",
        "test_b/",
        ".hidden_file",
        ".hidden_folder/",
    ];

    match_suggestions(&expected_paths, &suggestions);
}

#[test]
fn filecompletions_for_redirection_target() {
    let (_, _, engine, stack) = new_engine_helper(fs::fixtures().join("external_completions"));
    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let expected = vec!["`dir with space/bar baz`", "`dir with space/foo`"];
    let command = "(echo 'foo' o+e> `dir with space/`";
    let suggestions = completer.complete(command, command.len());
    match_suggestions(&expected, &suggestions);

    let command = "echo 'foo' o> foo e> `dir with space/`";
    let suggestions = completer.complete(command, command.len());
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::positional("spam ", "animal")]
#[case::optional("spam foo -f bar ", "fruit")]
#[case::rest1("spam foo -f bar baz ", "animal")]
#[case::rest2("spam foo -f bar baz qux ", "animal")]
#[case::long_flag1("spam --foo=", "animal")]
#[case::long_flag1("spam --foo=", "animal")]
#[case::long_flag_short("spam -f ", "animal")]
#[case::short_flag("spam -b ", "animal")]
/// When we're completing the flag name itself, not its value,
/// custom completions should not be used
#[case::long_flag_name_not_value("spam --f", "--foo")]
#[case::short_flag_name_not_value("spam -f", "-f")]
#[case::flags("spam -", "flags")]
// https://github.com/nushell/nushell/issues/16860
#[case::options_with_quotes1("spam --options ", "options")]
#[case::options_with_quotes2("spam --options \"", "options")]
#[case::options_with_quotes3("spam --options `", "options")]
#[case::options_with_quotes4("spam --options 'third", "\"third item")]
fn extern_custom_completion(
    mut extern_completer: NuCompleter,
    #[case] input: &str,
    #[case] answer: &str,
) {
    let suggestions = extern_completer.complete(input, input.len());
    let expected = match answer {
        "animal" => vec!["cat", "dog", "eel"],
        "fruit" => vec!["apple", "banana"],
        "options" => vec!["\"first item\"", "\"second item\"", "\"third item"],
        "flags" => vec!["--foo", "--options", "-b", "-f"],
        _ => vec![answer],
    };
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::cursor_before_word(8, vec![""])]
#[case::cursor_on_word_left_boundary(9, vec![""])]
#[case::cursor_next_to_word(12, vec!["bar"])]
#[case::cursor_after_word(13, vec!["bar", ""])]
fn custom_completer_triggers_cursor_before_word(
    mut custom_completer: NuCompleter,
    #[case] position: usize,
    #[case] extra: Vec<&str>,
) {
    let suggestions = custom_completer.complete("cmd foo  bar ", position);
    let mut expected: Vec<_> = vec!["cmd", "foo"];
    expected.extend(extra);
    match_suggestions(&expected, &suggestions);
}

#[rstest]
fn sort_fuzzy_completions_in_alphabetical_order(mut fuzzy_alpha_sort_completer: NuCompleter) {
    let suggestions = fuzzy_alpha_sort_completer.complete("ls nu", 5);
    // Even though "nushell" is a better match, it should come second because
    // the completions should be sorted in alphabetical order
    match_suggestions(&vec!["custom_completion.nu", "nushell"], &suggestions);
}

#[test]
fn exact_match() {
    let (dir, _, engine, stack) = new_partial_engine();

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    // Troll case to test if exact match logic works case insensitively
    let target_dir = format!("open {}", folder(dir.join("pArTiAL")));
    let suggestions = completer.complete(&target_dir, target_dir.len());
    match_suggestions(
        &vec![
            file(dir.join("partial").join("hello.txt")).as_str(),
            folder(dir.join("partial").join("hol")).as_str(),
        ],
        &suggestions,
    );

    let target_dir = format!("open {}", file(dir.join("partial").join("h")));
    let suggestions = completer.complete(&target_dir, target_dir.len());
    match_suggestions(
        &vec![
            file(dir.join("partial").join("hello.txt")).as_str(),
            folder(dir.join("partial").join("hol")).as_str(),
        ],
        &suggestions,
    );

    // Even though "hol" is an exact match, the first component ("part") wasn't an
    // exact match, so we include partial-a/hola
    let target_dir = format!("open {}", file(dir.join("part").join("hol")));
    let suggestions = completer.complete(&target_dir, target_dir.len());
    match_suggestions(
        &vec![
            folder(dir.join("partial").join("hol")).as_str(),
            folder(dir.join("partial-a").join("hola")).as_str(),
        ],
        &suggestions,
    );

    // Exact match behavior shouldn't be enabled if the path has no slashes
    let target_dir = format!("open {}", file(dir.join("partial")));
    let suggestions = completer.complete(&target_dir, target_dir.len());
    assert!(suggestions.len() > 1);
}

#[cfg(all(not(windows), not(target_os = "macos")))]
#[test]
fn exact_match_case_insensitive() {
    use nu_test_support::playground::Playground;
    use support::completions_helpers::new_engine_helper;

    Playground::setup("exact_match_case_insensitive", |dirs, playground| {
        playground.mkdir("AA/foo");
        playground.mkdir("aa/foo");
        playground.mkdir("aaa/foo");

        let (dir, _, engine, stack) = new_engine_helper(dirs.test().into());
        let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

        let target = format!("open {}", folder(dir.join("aa")));
        match_suggestions(
            &vec![
                folder(dir.join("AA").join("foo")).as_str(),
                folder(dir.join("aa").join("foo")).as_str(),
                folder(dir.join("aaa").join("foo")).as_str(),
            ],
            &completer.complete(&target, target.len()),
        );
    });
}

#[rstest]
fn alias_offset_bug_7648() {
    let (_, _, mut engine, mut stack) = new_engine();

    // Create an alias
    let alias = r#"alias ea = ^$env.EDITOR /tmp/test.s"#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let suggestions = completer.complete("e", 1);
    assert!(!suggestions.is_empty());

    // Make sure completion in complicated external head expression still works
    let input = "^(ls | e";
    let suggestions = completer.complete(input, input.len());
    assert!(!suggestions.is_empty());
}

#[rstest]
fn alias_offset_bug_7754() {
    let (_, _, mut engine, mut stack) = new_engine();

    // Create an alias
    let alias = r#"alias ll = ls -l"#;
    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let suggestions = completer.complete("ll -a | c", 9);
    assert!(!suggestions.is_empty());
}

#[rstest]
fn operator_completions(mut custom_completer: NuCompleter) {
    let suggestions = custom_completer.complete("1 ", 2);
    // == != > < >= <= in not-in
    // + - * / // mod **
    // 5 bit-xxx
    assert_eq!(20, suggestions.len());
    let suggestions = custom_completer.complete("1 bit-s", 7);
    let expected: Vec<_> = vec!["bit-shl", "bit-shr"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("'str' ", 6);
    // == != > < >= <= in not-in
    // has not-has starts-with not-starts-with ends-with not-ends-with
    // =~ !~ like not-like ++
    assert_eq!(19, suggestions.len());
    let suggestions = custom_completer.complete("'str' +", 7);
    let expected: Vec<_> = vec!["++"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("1ms ", 4);
    // == != > < >= <= in not-in
    // + - * / // mod
    assert_eq!(14, suggestions.len());
    let suggestions = custom_completer.complete("1ms /", 5);
    let expected: Vec<_> = vec!["/", "//"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("..2 ", 4);
    // == != in not-in has not-has
    assert_eq!(6, suggestions.len());
    let suggestions = custom_completer.complete("..2 h", 5);
    let expected: Vec<_> = vec!["has"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("[[];[]] ", 8);
    // == != in not-in has not-has ++
    assert_eq!(7, suggestions.len());
    let suggestions = custom_completer.complete("[[];[]] h", 9);
    let expected: Vec<_> = vec!["has"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("(date now) ", 11);
    // == != > < >= <= in not-in
    assert_eq!(8, suggestions.len());
    let suggestions = custom_completer.complete("(date now) <", 12);
    let expected: Vec<_> = vec!["<", "<="];
    match_suggestions(&expected, &suggestions);

    // default operators for all types
    let expected: Vec<_> = vec!["!=", "==", "in", "not-in"];
    let suggestions = custom_completer.complete("{1} ", 4);
    match_suggestions(&expected, &suggestions);
    let suggestions = custom_completer.complete("null ", 5);
    match_suggestions(&expected, &suggestions);
}

#[rstest]
fn cell_path_operator_completions(mut custom_completer: NuCompleter) {
    let suggestions = custom_completer.complete("[1].0 ", 6);
    // == != > < >= <= in not-in
    // + - * / // mod **
    // 5 bit-xxx
    assert_eq!(20, suggestions.len());
    let suggestions = custom_completer.complete("[1].0 bit-s", 11);
    let expected: Vec<_> = vec!["bit-shl", "bit-shr"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("{'foo': [1, 1kb]}.foo.1 ", 24);
    // == != > < >= <= in not-in
    // + - * / // mod
    assert_eq!(14, suggestions.len());
    let suggestions = custom_completer.complete("{'foo': [1, 1kb]}.foo.1 mo", 26);
    let expected: Vec<_> = vec!["mod"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("const f = {'foo': [1, '1']}; $f.foo.1 ", 38);
    // == != > < >= <= in not-in
    // has not-has starts-with not-starts-with ends-with not-ends-with
    // =~ !~ like not-like ++
    assert_eq!(19, suggestions.len());
    let suggestions = custom_completer.complete("const f = {'foo': [1, '1']}; $f.foo.1 ++", 40);
    let expected: Vec<_> = vec!["++"];
    match_suggestions(&expected, &suggestions);
}

#[rstest]
fn assignment_operator_completions(mut custom_completer: NuCompleter) {
    let suggestions = custom_completer.complete("mut foo = ''; $foo ", 19);
    // == != > < >= <= in not-in
    // has not-has starts-with not-starts-with ends-with not-ends-with
    // =~ !~ like not-like ++
    // = ++=
    assert_eq!(21, suggestions.len());
    let suggestions = custom_completer.complete("mut foo = ''; $foo ++", 21);
    let expected: Vec<_> = vec!["++", "++="];
    match_suggestions(&expected, &suggestions);

    // == != > < >= <= in not-in
    // =
    let suggestions = custom_completer.complete("mut foo = date now; $foo ", 25);
    assert_eq!(9, suggestions.len());
    let suggestions = custom_completer.complete("mut foo = date now; $foo =", 26);
    let expected: Vec<_> = vec!["=", "=="];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("mut foo = date now; $foo ", 25);
    // == != > < >= <= in not-in
    // =
    assert_eq!(9, suggestions.len());
    let suggestions = custom_completer.complete("mut foo = date now; $foo =", 26);
    let expected: Vec<_> = vec!["=", "=="];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("mut foo = 1ms; $foo ", 20);
    // == != > < >= <= in not-in
    // + - * / // mod
    // = += -= *= /=
    assert_eq!(19, suggestions.len());
    let suggestions = custom_completer.complete("mut foo = 1ms; $foo +", 21);
    let expected: Vec<_> = vec!["+", "+="];
    match_suggestions(&expected, &suggestions);

    // default operators for all mutables
    let expected: Vec<_> = vec!["!=", "=", "==", "in", "not-in"];
    let suggestions = custom_completer.complete("mut foo = null; $foo ", 21);
    match_suggestions(&expected, &suggestions);

    // $env should be considered mutable
    let suggestions = custom_completer.complete("$env.config.keybindings ", 24);
    // == != in not-in
    // has not-has ++=
    // = ++=
    assert_eq!(9, suggestions.len());
    let expected: Vec<_> = vec!["++", "++="];
    let suggestions = custom_completer.complete("$env.config.keybindings +", 25);
    match_suggestions(&expected, &suggestions);

    // all operators for type any
    let suggestions = custom_completer.complete("ls | where name ", 16);
    assert_eq!(32, suggestions.len());
    let expected: Vec<_> = vec!["starts-with"];
    let suggestions = custom_completer.complete("ls | where name starts", 22);
    match_suggestions(&expected, &suggestions);
}

#[test]
fn cellpath_assignment_operator_completions() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"mut foo = {'foo': [1, '1']}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "$foo.foo.1 ";
    let suggestions = completer.complete(completion_str, completion_str.len());
    // == != > < >= <= in not-in
    // has not-has starts-with not-starts-with ends-with not-ends-with
    // =~ !~ like not-like ++
    // = ++=
    assert_eq!(21, suggestions.len());
    let completion_str = "$foo.foo.1 ++";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["++", "++="];
    match_suggestions(&expected, &suggestions);

    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"mut foo = {'foo': [1, (date now)]}"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "$foo.foo.1 ";
    let suggestions = completer.complete(completion_str, completion_str.len());
    // == != > < >= <= in not-in
    // =
    assert_eq!(9, suggestions.len());
    let completion_str = "$foo.foo.1 =";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["=", "=="];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn alias_expansion_for_external_completions() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"alias example_alias = example_cmd arg1 arg2"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    // Define an external completer that returns the arguments passed to it
    let command = r#"$env.config.completions.external.completer = {|s| $s }"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "example_alias extra_arg";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec!["example_cmd", "arg1", "arg2", "extra_arg"];
    match_suggestions(&expected, &suggestions);
}

#[test]
fn nested_alias_expansion_for_external_completions() {
    let (_, _, mut engine, mut stack) = new_engine();
    let command = r#"alias example_alias = example_cmd arg1 arg2; alias nested_alias = example_alias nested_alias_arg"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    // Define an external completer that returns the arguments passed to it
    let command = r#"$env.config.completions.external.completer = {|s| $s }"#;
    assert!(support::merge_input(command.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let completion_str = "nested_alias extra_arg";
    let suggestions = completer.complete(completion_str, completion_str.len());
    let expected: Vec<_> = vec![
        "example_cmd",
        "arg1",
        "arg2",
        "nested_alias_arg",
        "extra_arg",
    ];
    match_suggestions(&expected, &suggestions);
}

// TODO: type inference
#[ignore]
#[rstest]
fn type_inferenced_operator_completions(mut custom_completer: NuCompleter) {
    let suggestions = custom_completer.complete("let f = {'foo': [1, '1']}; $f.foo.1 ", 36);
    // == != > < >= <= in not-in
    // has not-has starts-with not-starts-with ends-with not-ends-with
    // =~ !~ like not-like ++
    assert_eq!(19, suggestions.len());
    let suggestions = custom_completer.complete("const f = {'foo': [1, '1']}; $f.foo.1 ++", 38);
    let expected: Vec<_> = vec!["++"];
    match_suggestions(&expected, &suggestions);

    let suggestions = custom_completer.complete("mut foo = [(date now)]; $foo.0 ", 31);
    // == != > < >= <= in not-in
    // =
    assert_eq!(9, suggestions.len());
    let suggestions = custom_completer.complete("mut foo = [(date now)]; $foo.0 =", 32);
    let expected: Vec<_> = vec!["=", "=="];
    match_suggestions(&expected, &suggestions);
}

#[rstest]
#[case::substring(
    "substring", "😏foo かなfoo abfoo", "f",
    vec!["abfoo", "かなfoo", "😏foo"],
    vec![vec![2], vec![2], vec![1]]
)]
#[case::fuzzy(
    "fuzzy", "😏foo かなfoo abfoo", "f",
    vec!["😏foo", "abfoo", "かなfoo"],
    vec![vec![1], vec![2], vec![2]]
)]
#[case::substring_unicode_with_quotes(
    "substring", "かなfoo '`かなbar`'", "な",
    vec!["`かなbar`", "かなfoo"],
    vec![vec![2], vec![1]]
)]
#[case::prefix_unicode_with_quotes(
    "prefix", "かなfoo '`かなbar`'", "か",
    vec!["`かなbar`", "かなfoo"],
    vec![vec![1], vec![0]]
)]
fn suggestion_match_indices(
    #[case] matcher_algo: &str,
    #[case] options: &str,
    #[case] pattern: &str,
    #[case] expected_values: Vec<&str>,
    #[case] expected_indices: Vec<Vec<usize>>,
) {
    let (_, _, mut engine, mut stack) = new_engine();

    let config = format!("$env.config.completions.algorithm = '{matcher_algo}'");
    assert!(support::merge_input(config.as_bytes(), &mut engine, &mut stack).is_ok());

    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));

    let input = format!("def foo [a: string@[{options}]] {{}}; foo {pattern}");
    let suggestions = completer.complete(&input, input.len());

    assert_eq!(suggestions.len(), expected_values.len());
    assert_eq!(suggestions.len(), expected_indices.len());

    for ((value, indices), sugg) in expected_values
        .iter()
        .zip(expected_indices.into_iter())
        .zip(suggestions.iter())
    {
        assert_eq!(*value, sugg.value);
        assert_eq!(Some(indices), sugg.match_indices);
    }
}

#[test]
#[ignore = "run this test only when experimental option native-clip is set"]
fn clip_subcommands_show_before_and_after_use() {
    // Ensure `clip` subcommands (e.g. `clip copy`) appear in completions both before
    // and after `use std/clip`.
    let (_, _, mut engine, mut stack) = new_engine();

    // Before `use` — built-in `clip copy` should be present
    let mut completer = NuCompleter::new(Arc::new(engine.clone()), Arc::new(stack.clone()));
    let suggestions = completer.complete("clip ", 5);
    assert!(suggestions.iter().any(|s| s.value == "clip copy"));

    // Also check the no-space case (`clip`) returns subcommands
    let suggestions_no_space = completer.complete("clip", 4);
    assert!(suggestions_no_space.iter().any(|s| s.value == "clip copy"));

    // After `use std/clip` — completions should still include `clip copy`
    // load_standard_library registers the virtual std paths so `use std/clip` can be parsed
    assert!(load_standard_library(&mut engine).is_ok());
    assert!(support::merge_input("use std/clip".as_bytes(), &mut engine, &mut stack).is_ok());
    let mut completer2 = NuCompleter::new(Arc::new(engine), Arc::new(stack));
    let suggestions2 = completer2.complete("clip ", 5);
    assert!(suggestions2.iter().any(|s| s.value == "clip copy"));

    // And the no-space case after `use`
    let suggestions2_no_space = completer2.complete("clip", 4);
    assert!(suggestions2_no_space.iter().any(|s| s.value == "clip copy"));
}
