Macro lib::assert_io_read_to_string_contains

source · 
macro_rules! assert_io_read_to_string_contains {
    ($reader:expr, $containee:expr $(,)?) => { ... };
    ($a:expr, $b:expr, $($message:tt)+) => { ... };
}
Expand description

Assert a std::io::Read read_to_string() contains a pattern.

  • If true, return ().

  • Otherwise, call panic! with a message and the values of the expressions with their debug representations.

§Examples

use std::io::Read;

// Return Ok
let mut reader = "hello".as_bytes();
let containee = "ell";
assert_io_read_to_string_contains!(reader, containee);
//-> ()

// Panic with error message
let result = panic::catch_unwind(|| {
let mut reader = "hello".as_bytes();
let containee = "zzz";
assert_io_read_to_string_contains!(reader, containee);
//-> panic!
});
assert!(result.is_err());
let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
let expect = concat!(
    "assertion failed: `assert_io_read_to_string_contains!(reader, containee)`\n",
    "    reader label: `reader`,\n",
    "    reader debug: `[]`,\n",
    " containee label: `containee`,\n",
    " containee debug: `\"zzz\"`,\n",
    "    reader value: `\"hello\"`,\n",
    " containee value: `\"zzz\"`"
);
assert_eq!(actual, expect);

§Module macros