fn test_unified_diff_interleaved_changes()

in codex-rs/apply-patch/src/lib.rs [1033:1102]

• 59 lines of code
• 1 McCabe index (conditional complexity)

    fn test_unified_diff_interleaved_changes() {
        // Original file with six lines.
        let dir = tempdir().unwrap();
        let path = dir.path().join("interleaved.txt");
        fs::write(&path, "a\nb\nc\nd\ne\nf\n").unwrap();

        // Patch replaces two separate lines and appends a new one at EOF using
        // three distinct chunks.
        let patch_body = format!(
            r#"*** Update File: {}
@@
 a
-b
+B
@@
 d
-e
+E
@@
 f
+g
*** End of File"#,
            path.display()
        );
        let patch = wrap_patch(&patch_body);

        // Extract chunks then build the unified diff.
        let parsed = parse_patch(&patch).unwrap();
        let chunks = match parsed.as_slice() {
            [Hunk::UpdateFile { chunks, .. }] => chunks,
            _ => panic!("Expected a single UpdateFile hunk"),
        };

        let diff = unified_diff_from_chunks(&path, chunks).unwrap();

        let expected_diff = r#"@@ -1,6 +1,7 @@
 a
-b
+B
 c
 d
-e
+E
 f
+g
"#;

        let expected = ApplyPatchFileUpdate {
            unified_diff: expected_diff.to_string(),
            content: "a\nB\nc\nd\nE\nf\ng\n".to_string(),
        };

        assert_eq!(expected, diff);

        let mut stdout = Vec::new();
        let mut stderr = Vec::new();
        apply_patch(&patch, &mut stdout, &mut stderr).unwrap();
        let contents = fs::read_to_string(path).unwrap();
        assert_eq!(
            contents,
            r#"a
B
c
d
E
f
g
"#
        );
    }