Add global gitignore support to file exclusion logic

src/shared/gitignore.test.ts

@@ -1,11 +1,12 @@
-import { afterEach, beforeEach, describe, expect, test } from 'bun:test'
+import { afterEach, beforeEach, describe, expect, mock, test } from 'bun:test'
 import { mkdirSync, rmSync, writeFileSync } from 'fs'
 import { join } from 'path'
-import { loadGitignore } from './gitignore'
+import { _resetGlobalCache, loadGitignore } from './gitignore'
 
 const TEST_DIR = '/tmp/toes-gitignore-test'
 
 beforeEach(() => {
+  _resetGlobalCache()
   mkdirSync(TEST_DIR, { recursive: true })
 })
 
@@ -171,4 +172,64 @@ describe('loadGitignore', () => {
       expect(checker.shouldExclude('build/output')).toBe(true)
     })
   })
+
+  describe('global gitignore', () => {
+    const GLOBAL_IGNORE = '/tmp/toes-global-gitignore-test'
+
+    beforeEach(() => {
+      mkdirSync(GLOBAL_IGNORE, { recursive: true })
+    })
+
+    afterEach(() => {
+      rmSync(GLOBAL_IGNORE, { recursive: true, force: true })
+    })
+
+    test('should include patterns from global gitignore', () => {
+      const globalIgnorePath = join(GLOBAL_IGNORE, 'ignore')
+      writeFileSync(globalIgnorePath, '*.bak\n.idea/')
+
+      const origSpawnSync = require('child_process').spawnSync
+      const spawnSyncMock = mock((cmd: string, args: string[], opts: any) => {
+        if (cmd === 'git' && args.includes('core.excludesFile')) {
+          return { status: 0, stdout: globalIgnorePath + '\n', stderr: '' }
+        }
+        return origSpawnSync(cmd, args, opts)
+      })
+      mock.module('child_process', () => ({ spawnSync: spawnSyncMock }))
+      _resetGlobalCache()
+
+      const checker = loadGitignore(TEST_DIR)
+
+      expect(checker.shouldExclude('backup.bak')).toBe(true)
+      expect(checker.shouldExclude('src/old.bak')).toBe(true)
+      expect(checker.shouldExclude('.idea')).toBe(true)
+      expect(checker.shouldExclude('src/index.ts')).toBe(false)
+
+      mock.module('child_process', () => ({ spawnSync: origSpawnSync }))
+    })
+
+    test('should merge global and local patterns', () => {
+      const globalIgnorePath = join(GLOBAL_IGNORE, 'ignore')
+      writeFileSync(globalIgnorePath, '*.bak')
+      writeFileSync(join(TEST_DIR, '.gitignore'), '*.log')
+
+      const origSpawnSync = require('child_process').spawnSync
+      const spawnSyncMock = mock((cmd: string, args: string[], opts: any) => {
+        if (cmd === 'git' && args.includes('core.excludesFile')) {
+          return { status: 0, stdout: globalIgnorePath + '\n', stderr: '' }
+        }
+        return origSpawnSync(cmd, args, opts)
+      })
+      mock.module('child_process', () => ({ spawnSync: spawnSyncMock }))
+      _resetGlobalCache()
+
+      const checker = loadGitignore(TEST_DIR)
+
+      expect(checker.shouldExclude('backup.bak')).toBe(true)
+      expect(checker.shouldExclude('debug.log')).toBe(true)
+      expect(checker.shouldExclude('src/index.ts')).toBe(false)
+
+      mock.module('child_process', () => ({ spawnSync: origSpawnSync }))
+    })
+  })
 })

src/shared/gitignore.ts

@@ -1,4 +1,6 @@
+import { spawnSync } from 'child_process'
 import { existsSync, readFileSync } from 'fs'
+import { homedir } from 'os'
 import { join } from 'path'
 
 const ALWAYS_EXCLUDE = [
@@ -24,15 +26,46 @@ export interface GitignoreChecker {
 
 export function loadGitignore(appPath: string): GitignoreChecker {
   const gitignorePath = join(appPath, '.gitignore')
+  const globalPatterns = loadGlobalPatterns()
   const patterns = existsSync(gitignorePath)
-    ? [...ALWAYS_EXCLUDE, ...parseGitignore(readFileSync(gitignorePath, 'utf-8'))]
-    : DEFAULT_PATTERNS
+    ? [...ALWAYS_EXCLUDE, ...globalPatterns, ...parseGitignore(readFileSync(gitignorePath, 'utf-8'))]
+    : [...DEFAULT_PATTERNS, ...globalPatterns]
 
   return {
     shouldExclude: (path: string) => matchesPattern(path, patterns),
   }
 }
 
+export const _resetGlobalCache = () => {
+  cachedGlobalPatterns = undefined
+}
+
+let cachedGlobalPatterns: string[] | undefined
+
+const expandHome = (filepath: string) =>
+  filepath.startsWith('~/') ? join(homedir(), filepath.slice(2)) : filepath
+
+function getGlobalExcludesPath(): string | null {
+  const result = spawnSync('git', ['config', '--global', 'core.excludesFile'], {
+    encoding: 'utf-8',
+  })
+  if (result.status === 0 && result.stdout.trim()) {
+    return expandHome(result.stdout.trim())
+  }
+  const xdgHome = process.env.XDG_CONFIG_HOME || join(homedir(), '.config')
+  const defaultPath = join(xdgHome, 'git', 'ignore')
+  if (existsSync(defaultPath)) return defaultPath
+  return null
+}
+
+function loadGlobalPatterns(): string[] {
+  if (cachedGlobalPatterns !== undefined) return cachedGlobalPatterns
+  const path = getGlobalExcludesPath()
+  cachedGlobalPatterns =
+    path && existsSync(path) ? parseGitignore(readFileSync(path, 'utf-8')) : []
+  return cachedGlobalPatterns
+}
+
 function parseGitignore(content: string): string[] {
   return content
     .split('\n')