// Extreme TDD test to expose and fix long literal separator issues
// Following Toyota Way: Write test FIRST, then fix implementation

#[test]
fn test_numeric_literal_readability() {
    // TDD: This test exposes the long literal lacking separators issue
    // Known bug: Clippy warning "long literal lacking separators"
    // Pattern: Numbers with 5+ digits should have underscores for readability

    // Examples of hard-to-read literals:
    let unreadable_literals = vec![
        "10000",      // Should be: 10_000
        "100000",     // Should be: 100_000
        "1000000",    // Should be: 1_000_000
        "4294967295", // Should be: 4_294_967_295
    ];

    // Properly formatted with separators:
    let readable_literals = vec!["10_000", "100_000", "1_000_000", "4_294_967_295"];

    assert_eq!(unreadable_literals.len(), readable_literals.len());

    // Check that readable versions have underscores
    for readable in &readable_literals {
        assert!(
            readable.contains('_'),
            "Readable literal should contain underscores"
        );
    }

    // Check that unreadable versions don't have underscores
    for unreadable in &unreadable_literals {
        assert!(
            !unreadable.contains('_'),
            "Unreadable literal should not contain underscores"
        );
    }
}

#[test]
fn test_separator_placement_rules() {
    // TDD: This test documents the rules for separator placement

    // Rule: Add underscores every 3 digits from the right for decimal numbers
    let decimal_examples = vec![
        (1000, "1_000"),
        (10000, "10_000"),
        (100000, "100_000"),
        (1000000, "1_000_000"),
    ];

    for (numeric, formatted) in decimal_examples {
        assert!(numeric >= 1000, "Should format numbers >= 1000");
        assert!(
            formatted.contains('_'),
            "Formatted version should have separators"
        );
    }

    // Hexadecimal numbers should use underscores every 4 digits
    let hex_examples = vec![
        "0xFFFF",     // Could be: 0xFFFF (4 digits, optional)
        "0xFFFFFFFF", // Should be: 0xFFFF_FFFF
    ];

    assert_eq!(hex_examples.len(), 2);
}

#[test]
fn test_clippy_unreadable_literal_fix() {
    // TDD: This test verifies our understanding of the clippy fix

    // Clippy warning: "long literal lacking separators"
    // Lint name: unreadable_literal
    // Fix: Add underscores to improve readability

    let lint_name = "unreadable_literal";
    let fix_approach = "add_underscores";

    assert_eq!(lint_name, "unreadable_literal");
    assert_eq!(fix_approach, "add_underscores");

    // Examples from actual codebase that need fixing:
    // 100000 -> 100_000
    // 1000000 -> 1_000_000

    let needs_fixing = true;
    assert!(needs_fixing);
}
