#![no_main] use imara_diff::{Algorithm, BasicLineDiffPrinter, Diff, InternedInput, UnifiedDiffConfig};use libfuzzer_sys::arbitrary;use libfuzzer_sys::fuzz_target; /// Valid prefixes for unified diff output linesconst VALID_DIFF_LINE_PREFIXES: [char; 4] = [' ', '+', '-', '@']; #[derive(arbitrary::Arbitrary, Debug)]struct Input<'a> {    before: &'a str,    after: &'a str,    context_len: u32,} /// Tests unified diff printing with:/// - Different context lengths (0-10)/// - Various input combinations/// - Validates output format (lines start with ' ', '+', '-', or '@')fn do_fuzz(    Input {        before,        after,        context_len,    }: Input<'_>,) {    let input = InternedInput::new(before, after);     // Test with different algorithms    for algorithm in [        Algorithm::Histogram,        Algorithm::Myers,        Algorithm::MyersMinimal,    ] {        let mut diff = Diff::compute(algorithm, &input);         // Postprocess before printing        diff.postprocess_lines(&input);         // Create printer and config        let printer = BasicLineDiffPrinter(&input.interner);        let mut config = UnifiedDiffConfig::default();        config.context_len(context_len);         // Generate unified diff        let unified = diff.unified_diff(&printer, config, &input);        let output = unified.to_string();         // Basic sanity checks on output        // It should be valid UTF-8 (already guaranteed by to_string)        // Lines should start with valid diff prefixes        for line in output.lines() {            if !line.is_empty() {                let first_char = line.chars().next().unwrap();                // Should be a valid diff line prefix                assert!(                    VALID_DIFF_LINE_PREFIXES.contains(&first_char),                    "Invalid diff line prefix: '{}' in line: '{}'",                    first_char,                    line                );            }        }    }} fuzz_target!(|input: Input<'_>| {    do_fuzz(input);});