feat: zero-config indexing driven by .gitignore (#283) (#285)

Remove .codegraph/config.json and the entire config surface. CodeGraph now
indexes every file whose extension maps to a supported language and respects
.gitignore everywhere — git repos via git itself, non-git projects via the
`ignore` library (root + nested .gitignore files, the same way git does).

- Remove CodeGraphConfig/DEFAULT_CONFIG, src/config.ts, and the public config
  API (the `config` option on init, getConfig/updateConfig/getConfigPath).
- Derive the source-file allowlist from EXTENSION_MAP (isSourceFile); maxFileSize
  is now a constant. Drop the .codegraphignore marker.
- Behavior change: committed, non-gitignored dirs (vendor/, a committed dist/)
  are now indexed — .gitignore is the single source of truth.

Earlier inert fields (languages, frameworks, extractDocstrings, trackCallSites,
customPatterns) and their dead helpers are removed as part of this.

Resolves #283.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

__tests__/extraction.test.ts

@@ -9,10 +9,9 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
 import { CodeGraph } from '../src';
-import { extractFromSource, scanDirectory, shouldIncludeFile } from '../src/extraction';
+import { extractFromSource, scanDirectory } from '../src/extraction';
 import { detectLanguage, isLanguageSupported, getSupportedLanguages, initGrammars, loadAllGrammars } from '../src/extraction/grammars';
 import { normalizePath } from '../src/utils';
-import { DEFAULT_CONFIG } from '../src/types';
 
 beforeAll(async () => {
   await initGrammars();
@@ -3003,39 +3002,57 @@ describe('Directory Exclusion', () => {
     cleanupTempDir(tempDir);
   });
 
-  it('should exclude node_modules directories', () => {
-    // Create structure: src/index.ts + node_modules/pkg/index.js
+  it('should exclude directories listed in .gitignore', () => {
+    // Create structure: src/index.ts + node_modules/pkg/index.js, gitignore node_modules
     const srcDir = path.join(tempDir, 'src');
     const nmDir = path.join(tempDir, 'node_modules', 'pkg');
     fs.mkdirSync(srcDir, { recursive: true });
     fs.mkdirSync(nmDir, { recursive: true });
     fs.writeFileSync(path.join(srcDir, 'index.ts'), 'export const x = 1;');
     fs.writeFileSync(path.join(nmDir, 'index.js'), 'module.exports = {};');
+    fs.writeFileSync(path.join(tempDir, '.gitignore'), 'node_modules/\n');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: tempDir };
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     expect(files).toContain('src/index.ts');
     expect(files.every((f) => !f.includes('node_modules'))).toBe(true);
   });
 
-  it('should exclude nested node_modules directories', () => {
-    // Create structure: packages/app/node_modules/pkg/index.js
+  it('should exclude nested node_modules via a root .gitignore', () => {
+    // A trailing-slash pattern with no leading slash matches at any depth.
     const srcDir = path.join(tempDir, 'packages', 'app', 'src');
     const nmDir = path.join(tempDir, 'packages', 'app', 'node_modules', 'pkg');
     fs.mkdirSync(srcDir, { recursive: true });
     fs.mkdirSync(nmDir, { recursive: true });
     fs.writeFileSync(path.join(srcDir, 'index.ts'), 'export const x = 1;');
     fs.writeFileSync(path.join(nmDir, 'index.js'), 'module.exports = {};');
+    fs.writeFileSync(path.join(tempDir, '.gitignore'), 'node_modules/\n');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: tempDir };
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     expect(files).toContain('packages/app/src/index.ts');
     expect(files.every((f) => !f.includes('node_modules'))).toBe(true);
   });
 
-  it('should exclude .git directories', () => {
+  it('should apply a nested .gitignore only to its own subtree', () => {
+    const appSrc = path.join(tempDir, 'app', 'src');
+    fs.mkdirSync(appSrc, { recursive: true });
+    fs.writeFileSync(path.join(appSrc, 'keep.ts'), 'export const a = 1;');
+    fs.writeFileSync(path.join(appSrc, 'skip.ts'), 'export const b = 2;');
+    fs.writeFileSync(path.join(tempDir, 'app', '.gitignore'), 'src/skip.ts\n');
+    // A sibling with the same name outside app/ must NOT be ignored.
+    const otherDir = path.join(tempDir, 'other', 'src');
+    fs.mkdirSync(otherDir, { recursive: true });
+    fs.writeFileSync(path.join(otherDir, 'skip.ts'), 'export const c = 3;');
+
+    const files = scanDirectory(tempDir);
+
+    expect(files).toContain('app/src/keep.ts');
+    expect(files).not.toContain('app/src/skip.ts');
+    expect(files).toContain('other/src/skip.ts');
+  });
+
+  it('should always skip .git directories', () => {
     const srcDir = path.join(tempDir, 'src');
     const gitDir = path.join(tempDir, '.git', 'objects');
     fs.mkdirSync(srcDir, { recursive: true });
@@ -3043,8 +3060,7 @@ describe('Directory Exclusion', () => {
     fs.writeFileSync(path.join(srcDir, 'index.ts'), 'export const x = 1;');
     fs.writeFileSync(path.join(gitDir, 'pack.ts'), 'export const y = 2;');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: tempDir };
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     expect(files).toContain('src/index.ts');
     expect(files.every((f) => !f.includes('.git'))).toBe(true);
@@ -3055,29 +3071,12 @@ describe('Directory Exclusion', () => {
     fs.mkdirSync(srcDir, { recursive: true });
     fs.writeFileSync(path.join(srcDir, 'Button.tsx'), 'export function Button() {}');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: tempDir };
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     expect(files.length).toBe(1);
     expect(files[0]).toBe('src/components/Button.tsx');
     expect(files[0]).not.toContain('\\');
   });
-
-  it('should respect .codegraphignore marker', () => {
-    const srcDir = path.join(tempDir, 'src');
-    const vendorDir = path.join(tempDir, 'vendor');
-    fs.mkdirSync(srcDir, { recursive: true });
-    fs.mkdirSync(vendorDir, { recursive: true });
-    fs.writeFileSync(path.join(srcDir, 'index.ts'), 'export const x = 1;');
-    fs.writeFileSync(path.join(vendorDir, 'lib.ts'), 'export const y = 2;');
-    fs.writeFileSync(path.join(vendorDir, '.codegraphignore'), '');
-
-    const config = { ...DEFAULT_CONFIG, rootDir: tempDir };
-    const files = scanDirectory(tempDir, config);
-
-    expect(files).toContain('src/index.ts');
-    expect(files.every((f) => !f.includes('vendor'))).toBe(true);
-  });
 });
 
 describe('Git Submodules', () => {
@@ -3124,8 +3123,7 @@ describe('Git Submodules', () => {
     );
     git(mainDir, 'commit', '-q', '-m', 'add submodule');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: mainDir };
-    const files = scanDirectory(mainDir, config);
+    const files = scanDirectory(mainDir);
 
     expect(files).toContain('app.ts');
     expect(files).toContain('libs/lib/lib.ts');
@@ -3173,8 +3171,7 @@ describe('Nested non-submodule git repos', () => {
     git(path.join(root, 'sub_repo2'), 'init', '-q');
     fs.writeFileSync(path.join(sub2, 'two.ts'), 'export const two = 2;');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: root };
-    const files = scanDirectory(root, config);
+    const files = scanDirectory(root);
 
     // Both committed and untracked source from the nested repos must be found.
     expect(files).toContain('sub_repo1/src/one.ts');
@@ -3197,8 +3194,7 @@ describe('Nested non-submodule git repos', () => {
     fs.writeFileSync(path.join(sub, 'real.ts'), 'export const real = 1;');
     fs.writeFileSync(path.join(sub, 'generated.ts'), 'export const generated = 1;');
 
-    const config = { ...DEFAULT_CONFIG, rootDir: root };
-    const files = scanDirectory(root, config);
+    const files = scanDirectory(root);
 
     expect(files).toContain('sub_repo/src/real.ts');
     expect(files).not.toContain('sub_repo/src/generated.ts');

__tests__/foundation.test.ts

@@ -9,8 +9,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
 import { CodeGraph } from '../src';
-import { DEFAULT_CONFIG, Node, Edge } from '../src/types';
-import { loadConfig, saveConfig } from '../src/config';
+import { Node, Edge } from '../src/types';
 import { isInitialized, getCodeGraphDir, validateDirectory } from '../src/directory';
 import { DatabaseConnection, getDatabasePath } from '../src/db';
 
@@ -60,41 +59,12 @@ describe('CodeGraph Foundation', () => {
       cg.close();
     });
 
-    it('should create config.json with defaults', () => {
-      const cg = CodeGraph.initSync(tempDir);
-
-      const configPath = path.join(getCodeGraphDir(tempDir), 'config.json');
-      expect(fs.existsSync(configPath)).toBe(true);
-
-      const config = cg.getConfig();
-      expect(config.version).toBe(DEFAULT_CONFIG.version);
-      expect(config.include).toEqual(DEFAULT_CONFIG.include);
-      expect(config.exclude).toEqual(DEFAULT_CONFIG.exclude);
-
-      cg.close();
-    });
-
     it('should throw if already initialized', () => {
       const cg = CodeGraph.initSync(tempDir);
       cg.close();
 
       expect(() => CodeGraph.initSync(tempDir)).toThrow(/already initialized/i);
     });
-
-    it('should accept custom config options', () => {
-      const cg = CodeGraph.initSync(tempDir, {
-        config: {
-          maxFileSize: 500000,
-          extractDocstrings: false,
-        },
-      });
-
-      const config = cg.getConfig();
-      expect(config.maxFileSize).toBe(500000);
-      expect(config.extractDocstrings).toBe(false);
-
-      cg.close();
-    });
   });
 
   describe('Opening Projects', () => {
@@ -112,17 +82,6 @@ describe('CodeGraph Foundation', () => {
     it('should throw if not initialized', () => {
       expect(() => CodeGraph.openSync(tempDir)).toThrow(/not initialized/i);
     });
-
-    it('should preserve configuration across open/close', () => {
-      const cg1 = CodeGraph.initSync(tempDir, {
-        config: { maxFileSize: 123456 },
-      });
-      cg1.close();
-
-      const cg2 = CodeGraph.openSync(tempDir);
-      expect(cg2.getConfig().maxFileSize).toBe(123456);
-      cg2.close();
-    });
   });
 
   describe('Static Methods', () => {
@@ -182,31 +141,6 @@ describe('CodeGraph Foundation', () => {
     });
   });
 
-  describe('Configuration', () => {
-    it('should load and merge config with defaults', () => {
-      const cg = CodeGraph.initSync(tempDir);
-      cg.close();
-
-      const config = loadConfig(tempDir);
-      expect(config.version).toBe(DEFAULT_CONFIG.version);
-      expect(config.rootDir).toBe(path.resolve(tempDir));
-    });
-
-    it('should update configuration', () => {
-      const cg = CodeGraph.initSync(tempDir);
-
-      cg.updateConfig({ maxFileSize: 999999 });
-
-      expect(cg.getConfig().maxFileSize).toBe(999999);
-
-      cg.close();
-
-      // Verify persistence
-      const config = loadConfig(tempDir);
-      expect(config.maxFileSize).toBe(999999);
-    });
-  });
-
   describe('Directory Management', () => {
     it('should validate directory structure', () => {
       const cg = CodeGraph.initSync(tempDir);

__tests__/security.test.ts

@@ -15,9 +15,7 @@ import * as os from 'os';
 import { FileLock } from '../src/utils';
 import CodeGraph from '../src/index';
 import { ToolHandler, tools } from '../src/mcp/tools';
-import { shouldIncludeFile, scanDirectory } from '../src/extraction';
-import { shouldIncludeFile as configShouldInclude } from '../src/config';
-import { CodeGraphConfig, DEFAULT_CONFIG } from '../src/types';
+import { scanDirectory, isSourceFile } from '../src/extraction';
 import { DatabaseConnection, getDatabasePath } from '../src/db';
 import { QueryBuilder } from '../src/db/queries';
 
@@ -298,58 +296,24 @@ describe('Atomic Writes', () => {
   });
 });
 
-describe('Glob Matching (picomatch)', () => {
-  const makeConfig = (include: string[], exclude: string[]): CodeGraphConfig => ({
-    ...DEFAULT_CONFIG,
-    rootDir: '/test',
-    include,
-    exclude,
+describe('Source file detection (isSourceFile)', () => {
+  it('selects files by supported extension', () => {
+    expect(isSourceFile('src/index.ts')).toBe(true);
+    expect(isSourceFile('src/deep/nested/file.ts')).toBe(true);
+    expect(isSourceFile('src/component.tsx')).toBe(true);
+    expect(isSourceFile('lib/util.js')).toBe(true);
+    expect(isSourceFile('src/main.py')).toBe(true);
   });
 
-  it('should match standard glob patterns in extraction', () => {
-    const config = makeConfig(['**/*.ts'], ['node_modules/**']);
-
-    expect(shouldIncludeFile('src/index.ts', config)).toBe(true);
-    expect(shouldIncludeFile('src/deep/nested/file.ts', config)).toBe(true);
-    expect(shouldIncludeFile('src/index.js', config)).toBe(false);
-    expect(shouldIncludeFile('node_modules/lib/index.ts', config)).toBe(false);
+  it('rejects unsupported extensions and extensionless files', () => {
+    expect(isSourceFile('src/component.css')).toBe(false);
+    expect(isSourceFile('README.md')).toBe(false);
+    expect(isSourceFile('Makefile')).toBe(false);
+    expect(isSourceFile('.gitignore')).toBe(false);
   });
 
-  it('should match standard glob patterns in config', () => {
-    const config = makeConfig(['**/*.py'], ['__pycache__/**']);
-
-    expect(configShouldInclude('src/main.py', config)).toBe(true);
-    expect(configShouldInclude('src/main.ts', config)).toBe(false);
-    expect(configShouldInclude('__pycache__/module.py', config)).toBe(false);
-  });
-
-  it('should handle complex glob patterns correctly', () => {
-    const config = makeConfig(['src/**/*.{ts,tsx}', 'lib/**/*.js'], []);
-
-    expect(shouldIncludeFile('src/component.ts', config)).toBe(true);
-    expect(shouldIncludeFile('src/component.tsx', config)).toBe(true);
-    expect(shouldIncludeFile('lib/util.js', config)).toBe(true);
-    expect(shouldIncludeFile('src/component.css', config)).toBe(false);
-  });
-
-  it('should handle patterns that previously caused ReDoS', () => {
-    // This pattern would cause catastrophic backtracking with hand-rolled regex
-    const evilPattern = '**/**/**/**/**/**/**/**/**/**/**/**/**/**/a';
-    const config = makeConfig([evilPattern], []);
-
-    const start = Date.now();
-    // This should return quickly, not hang
-    shouldIncludeFile('x/x/x/x/x/x/x/x/x/x/x/x/x/x/b', config);
-    const elapsed = Date.now() - start;
-
-    // Should complete in under 100ms, not seconds
-    expect(elapsed).toBeLessThan(100);
-  });
-
-  it('should handle dot files correctly', () => {
-    const config = makeConfig(['**/*.ts'], []);
-
-    expect(shouldIncludeFile('.hidden/index.ts', config)).toBe(true);
+  it('matches regardless of leading dot directories', () => {
+    expect(isSourceFile('.hidden/index.ts')).toBe(true);
   });
 });
 
@@ -464,15 +428,9 @@ describe('Symlink Cycle Detection', () => {
       return;
     }
 
-    const config: CodeGraphConfig = {
-      ...DEFAULT_CONFIG,
-      rootDir: tempDir,
-      include: ['**/*.ts'],
-      exclude: [],
-    };
 
     // This should complete without hanging
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     // Should find the real file but not loop infinitely
     expect(files).toContain('src/index.ts');
@@ -496,14 +454,8 @@ describe('Symlink Cycle Detection', () => {
       return;
     }
 
-    const config: CodeGraphConfig = {
-      ...DEFAULT_CONFIG,
-      rootDir: tempDir,
-      include: ['**/*.ts'],
-      exclude: [],
-    };
 
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
 
     // Should find files from both the real dir and via the symlink
     // But deduplicate since they resolve to the same real path
@@ -521,15 +473,9 @@ describe('Symlink Cycle Detection', () => {
       return;
     }
 
-    const config: CodeGraphConfig = {
-      ...DEFAULT_CONFIG,
-      rootDir: tempDir,
-      include: ['**/*.ts'],
-      exclude: [],
-    };
 
     // Should not throw
-    const files = scanDirectory(tempDir, config);
+    const files = scanDirectory(tempDir);
     expect(files).toContain('src/valid.ts');
   });
 });

__tests__/sync.test.ts

@@ -281,11 +281,11 @@ describe('Sync Module', () => {
       expect(nodes.length).toBe(0);
     });
 
-    it('should skip files not matching config', async () => {
-      // Create a .js file which doesn't match **/*.ts
+    it('should skip files with unsupported extensions', async () => {
+      // A .txt file has no supported grammar, so sync must not index it.
       fs.writeFileSync(
-        path.join(testDir, 'src', 'ignored.js'),
-        `function ignored() {}`
+        path.join(testDir, 'src', 'notes.txt'),
+        `just some notes`
       );
 
       const result = await cg.sync();

__tests__/watch-policy.test.ts

@@ -12,7 +12,6 @@ import * as path from 'path';
 import * as os from 'os';
 import { watchDisabledReason } from '../src/sync/watch-policy';
 import { FileWatcher } from '../src/sync/watcher';
-import type { CodeGraphConfig } from '../src/types';
 
 describe('watchDisabledReason', () => {
   it('returns a reason when CODEGRAPH_NO_WATCH=1', () => {
@@ -63,18 +62,6 @@ describe('watchDisabledReason', () => {
 describe('FileWatcher honors the watch policy', () => {
   let testDir: string;
 
-  const baseConfig: CodeGraphConfig = {
-    version: 1,
-    rootDir: '.',
-    include: ['**/*.ts'],
-    exclude: ['**/node_modules/**'],
-    languages: [],
-    frameworks: [],
-    maxFileSize: 1024 * 1024,
-    extractDocstrings: true,
-    trackCallSites: true,
-  };
-
   afterEach(() => {
     delete process.env.CODEGRAPH_NO_WATCH;
     if (testDir && fs.existsSync(testDir)) {
@@ -87,7 +74,7 @@ describe('FileWatcher honors the watch policy', () => {
     process.env.CODEGRAPH_NO_WATCH = '1';
 
     const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-    const watcher = new FileWatcher(testDir, baseConfig, syncFn);
+    const watcher = new FileWatcher(testDir, syncFn);
 
     expect(watcher.start()).toBe(false);
     expect(watcher.isActive()).toBe(false);

__tests__/watcher.test.ts

@@ -9,7 +9,6 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
 import { FileWatcher } from '../src/sync/watcher';
-import type { CodeGraphConfig } from '../src/types';
 import CodeGraph from '../src/index';
 
 /**
@@ -34,18 +33,6 @@ function waitFor(
 describe('FileWatcher', () => {
   let testDir: string;
 
-  const baseConfig: CodeGraphConfig = {
-    version: 1,
-    rootDir: '.',
-    include: ['**/*.ts', '**/*.js'],
-    exclude: ['**/node_modules/**', '**/dist/**'],
-    languages: [],
-    frameworks: [],
-    maxFileSize: 1024 * 1024,
-    extractDocstrings: true,
-    trackCallSites: true,
-  };
-
   beforeEach(() => {
     testDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-watcher-'));
     // Create a source file so the directory isn't empty
@@ -63,7 +50,7 @@ describe('FileWatcher', () => {
   describe('start/stop lifecycle', () => {
     it('should start and stop without errors', () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn);
+      const watcher = new FileWatcher(testDir, syncFn);
 
       const started = watcher.start();
       expect(started).toBe(true);
@@ -75,7 +62,7 @@ describe('FileWatcher', () => {
 
     it('should be idempotent on double start', () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn);
+      const watcher = new FileWatcher(testDir, syncFn);
 
       expect(watcher.start()).toBe(true);
       expect(watcher.start()).toBe(true); // Should not throw
@@ -86,7 +73,7 @@ describe('FileWatcher', () => {
 
     it('should be idempotent on double stop', () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn);
+      const watcher = new FileWatcher(testDir, syncFn);
 
       watcher.start();
       watcher.stop();
@@ -98,7 +85,7 @@ describe('FileWatcher', () => {
   describe('debounced sync', () => {
     it('should trigger sync after file change', async () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 1, durationMs: 10 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, { debounceMs: 200 });
+      const watcher = new FileWatcher(testDir, syncFn, { debounceMs: 200 });
 
       watcher.start();
 
@@ -114,7 +101,7 @@ describe('FileWatcher', () => {
 
     it('should debounce rapid changes into a single sync', async () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 1, durationMs: 10 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, { debounceMs: 500 });
+      const watcher = new FileWatcher(testDir, syncFn, { debounceMs: 500 });
 
       watcher.start();
 
@@ -140,7 +127,7 @@ describe('FileWatcher', () => {
   describe('filtering', () => {
     it('should ignore files not matching include patterns', async () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, { debounceMs: 200 });
+      const watcher = new FileWatcher(testDir, syncFn, { debounceMs: 200 });
 
       watcher.start();
 
@@ -160,7 +147,7 @@ describe('FileWatcher', () => {
 
     it('should ignore .codegraph directory changes', async () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 0, durationMs: 0 });
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, { debounceMs: 200 });
+      const watcher = new FileWatcher(testDir, syncFn, { debounceMs: 200 });
 
       watcher.start();
 
@@ -185,7 +172,7 @@ describe('FileWatcher', () => {
     it('should call onSyncComplete after successful sync', async () => {
       const syncFn = vi.fn().mockResolvedValue({ filesChanged: 2, durationMs: 50 });
       const onSyncComplete = vi.fn();
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, {
+      const watcher = new FileWatcher(testDir, syncFn, {
         debounceMs: 200,
         onSyncComplete,
       });
@@ -203,7 +190,7 @@ describe('FileWatcher', () => {
     it('should call onSyncError when sync throws', async () => {
       const syncFn = vi.fn().mockRejectedValue(new Error('sync failed'));
       const onSyncError = vi.fn();
-      const watcher = new FileWatcher(testDir, baseConfig, syncFn, {
+      const watcher = new FileWatcher(testDir, syncFn, {
         debounceMs: 200,
         onSyncError,
       });