Add unit tests for TUI helpers

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
banga · armanarutiunov · Feb 11, 2026 · Feb 11, 2026 · Feb 11, 2026 · Feb 11, 2026
commit 211ffe479c1c94dc9ca60ef97d98f67fff4f91a5
diff --git a/src/tui/tui.test.ts b/src/tui/tui.test.ts
@@ -0,0 +1,173 @@
+import { truncateAnsi } from './Screen';
+import { getFileIcon } from './fileIcons';
+import { binarySearchBoundary } from './sync';
+import { buildTree, flattenVisible } from './FileTreePanel';
+import { DiffFile } from './collectDiffData';
+
+const RESET = '\x1b[0m';
+
+describe('truncateAnsi', () => {
+    test('plain text within limit', () => {
+        expect(truncateAnsi('hello', 10)).toBe('hello');
+    });
+
+    test('plain text exceeding limit', () => {
+        const result = truncateAnsi('hello world', 5);
+        expect(result).toBe('hello' + RESET);
+    });
+
+    test('zero width returns reset only', () => {
+        const result = truncateAnsi('hello', 0);
+        expect(result).toBe(RESET);
+    });
+
+    test('preserves ANSI escapes, truncates visible chars', () => {
+        const input = '\x1b[31mhello\x1b[0m world';
+        const result = truncateAnsi(input, 5);
+        // Should contain 'hello' colored red but not ' world'
+        expect(result).toContain('\x1b[31m');
+        expect(result.replace(/\x1b\[[0-9;]*m/g, '')).toBe('hello');
+    });
+
+    test('empty string returns empty', () => {
+        expect(truncateAnsi('', 10)).toBe('');
+    });
+
+    test('exact width returns unchanged', () => {
+        expect(truncateAnsi('abcde', 5)).toBe('abcde');
+    });
+});
+
+describe('getFileIcon', () => {
+    test('.ts extension', () => {
+        expect(getFileIcon('src/foo.ts')).toBe('\ue628');
+    });
+
+    test('.tsx extension', () => {
+        expect(getFileIcon('Component.tsx')).toBe('\ue7ba');
+    });
+
+    test('unknown extension returns default', () => {
+        expect(getFileIcon('file.xyz')).toBe('\uf15b');
+    });
+
+    test('Dockerfile without extension', () => {
+        expect(getFileIcon('Dockerfile')).toBe('\ue7b0');
+    });
+
+    test('Dockerfile with suffix', () => {
+        expect(getFileIcon('Dockerfile.prod')).toBe('\ue7b0');
+    });
+
+    test('.gitignore', () => {
+        expect(getFileIcon('.gitignore')).toBe('\ue702');
+    });
+
+    test('case-insensitive extension', () => {
+        expect(getFileIcon('README.MD')).toBe('\ue73e');
+    });
+});
+
+describe('binarySearchBoundary', () => {
+    test('single boundary', () => {
+        expect(binarySearchBoundary([0], 5)).toBe(0);
+    });
+
+    test('exact match returns that index', () => {
+        expect(binarySearchBoundary([0, 10, 20], 10)).toBe(1);
+    });
+
+    test('between boundaries returns lower', () => {
+        expect(binarySearchBoundary([0, 10, 20], 15)).toBe(1);
+    });
+
+    test('before first boundary returns 0', () => {
+        expect(binarySearchBoundary([5, 10, 20], 2)).toBe(0);
+    });
+
+    test('after last boundary returns last index', () => {
+        expect(binarySearchBoundary([0, 10, 20], 100)).toBe(2);
+    });
+
+    test('at first boundary returns 0', () => {
+        expect(binarySearchBoundary([0, 10, 20], 0)).toBe(0);
+    });
+
+    test('at last boundary returns last index', () => {
+        expect(binarySearchBoundary([0, 10, 20], 20)).toBe(2);
+    });
+});
+
+function makeDiffFile(fileNameB: string): DiffFile {
+    return {
+        displayName: fileNameB,
+        fileNameA: '',
+        fileNameB,
+        additions: 0,
+        deletions: 0,
+        startLineIndex: 0,
+    };
+}
+
+describe('buildTree', () => {
+    test('single file at root', () => {
+        const tree = buildTree([makeDiffFile('README.md')]);
+        expect(tree).toHaveLength(1);
+        expect(tree[0].type).toBe('file');
+        expect(tree[0].name).toBe('README.md');
+    });
+
+    test('nested file creates dir nodes', () => {
+        const tree = buildTree([makeDiffFile('src/tui/App.ts')]);
+        expect(tree).toHaveLength(1);
+        expect(tree[0].type).toBe('dir');
+        expect(tree[0].name).toBe('src');
+        const src = tree[0] as { children: any[] };
+        expect(src.children[0].type).toBe('dir');
+        expect(src.children[0].name).toBe('tui');
+    });
+
+    test('sibling files share dir node', () => {
+        const tree = buildTree([
+            makeDiffFile('src/a.ts'),
+            makeDiffFile('src/b.ts'),
+        ]);
+        expect(tree).toHaveLength(1);
+        expect(tree[0].type).toBe('dir');
+        const src = tree[0] as { children: any[] };
+        expect(src.children).toHaveLength(2);
+    });
+});
+
+describe('flattenVisible', () => {
+    test('returns dirs and files in order', () => {
+        const tree = buildTree([
+            makeDiffFile('src/a.ts'),
+            makeDiffFile('src/b.ts'),
+            makeDiffFile('README.md'),
+        ]);
+        const visible = flattenVisible(tree);
+        // dir 'src', file 'a.ts', file 'b.ts', file 'README.md'
+        expect(visible).toHaveLength(4);
+        expect(visible[0].type).toBe('dir');
+        expect(visible[1].type).toBe('file');
+        expect(visible[2].type).toBe('file');
+        expect(visible[3].type).toBe('file');
+    });
+
+    test('collapsed dir hides children', () => {
+        const tree = buildTree([
+            makeDiffFile('src/a.ts'),
+            makeDiffFile('README.md'),
+        ]);
+        // Collapse 'src'
+        const srcDir = tree[0] as { expanded: boolean };
+        srcDir.expanded = false;
+        const visible = flattenVisible(tree);
+        // dir 'src' (collapsed), file 'README.md'
+        expect(visible).toHaveLength(2);
+        expect(visible[0].type).toBe('dir');
+        expect(visible[1].type).toBe('file');
+        expect(visible[1].node.name).toBe('README.md');
+    });
+});