feat: add directory/file path completion for terminal input

[wenshao]

Background

Users frequently need to reference file paths in prompts (e.g. src/components/auth/LoginForm.tsx). Currently they must type full paths manually, which is error-prone and slow in large projects with deep directory structures.

Related: Item-18: Directory/File Path Completion

Before / After

	Before	After
File referencing	Only @ prefix triggers file completion	Also supports /, ./, ../, ~/ as path prefixes
Absolute paths	/home/user/... misidentified as a slash command — no suggestions shown	Recognized as a path, shows filesystem suggestions
Workflow	Must remember and type full paths manually	Shell-like Tab completion — browse directories level by level

Implementation

• directoryCompletion.ts — Directory scanning with LRU cache (500 entries, 5min TTL), .gitignore-aware filtering
• usePathCompletion.ts — React hook with 100ms debounce + AbortController to cancel stale requests
• useCommandCompletion.tsx — New CompletionMode.PATH; resolves SLASH/PATH conflict so /home is no longer treated as a slash command

Changes

Type	File	Description
New	utils/directoryCompletion.ts (+348)	Core completion logic
New	hooks/usePathCompletion.ts (+167)	Path completion hook
Modified	hooks/useCommandCompletion.tsx (+57/-8)	Integrate PATH mode
Tests	3 test files (+530)	48 test cases covering path parsing, Unicode, mode disambiguation, etc.

Tests

 ✓ directoryCompletion.test.ts  (24 tests)
 ✓ usePathCompletion.test.ts     (2 tests)
 ✓ useCommandCompletion.test.ts (22 tests)
 ✓ InputPrompt.test.tsx        (105 tests | 1 skipped)
 0 new TypeScript errors

Manual verification: Launch the CLI, type ./sr — you should see suggestions like src/. Press Tab to accept and continue completing the next directory level.

[github-actions]

📋 Review Summary

This PR implements path auto-completion for the terminal input, adding file and directory completion functionality inspired by Claude Code. The implementation includes a well-structured LRU-cached directory scanning system with proper React hook integration. Overall, this is a solid implementation with good test coverage, though there are a few areas that could be improved for robustness and maintainability.

🔍 General Feedback

• Good architectural separation: The code is well-organized with clear separation between the core utility logic (directoryCompletion.ts) and the React hook (usePathCompletion.ts).
• Comprehensive test coverage: 21 unit tests for the core module and proper mock setup for the hook tests demonstrate good testing practices.
• Thoughtful caching strategy: The LRU cache implementation with TTL helps avoid excessive filesystem I/O, which is crucial for CLI responsiveness.
• Proper async handling: Use of AbortController for cancelling stale searches and debounce logic shows attention to race condition prevention.
• The slash command vs. absolute path disambiguation is a clever fix that addresses a real edge case discovered during development.

🎯 Specific Feedback

🟡 High

• File: directoryCompletion.ts:172-182 - The isPathLikeToken function checks for Windows paths but only matches paths with a backslash after the drive letter (/^[a-zA-Z]:\\/). This regex won't match forward-slash Windows paths (which Node.js supports). Consider also supporting /^[a-zA-Z]:\\// or normalizing path separators before the check.

• File: usePathCompletion.ts:88-113 - The isActiveRef pattern is used to track whether this hook is the "active" completion source, but the logic at line 93 (if (isActiveRef.current)) only clears suggestions if we're already active. This could lead to stale suggestions if another completion source becomes active while this hook is still loading. Consider always clearing suggestions when resetCompletionState is called from an external source.

🟢 Medium

• File: directoryCompletion.ts:52-54 - The SimpleLRUCache.get() method refreshes entries by deleting and re-adding them on every access. This is O(n) for Map operations in some JS engines when iterating. Consider using a true doubly-linked list implementation for O(1) LRU, or document that this is a "simple" implementation with this known limitation.

• File: directoryCompletion.ts:267-280 - The logic to construct dirPortion is complex and could be simplified. The comment helps, but extracting this into a separate helper function (e.g., buildRelativePathPrefix) would improve readability and testability.

• File: useCommandCompletion.tsx:141-151 - The PATH mode detection only triggers on cursorRow === 0 (first line). This is reasonable for command input, but the restriction should be documented with a comment explaining why multi-line path completion isn't supported (if intentional).

• File: directoryCompletion.test.ts:56-59 - The test for parsePartialPath with empty input has a TODO-like pattern where process.cwd is mocked but not restored in an afterEach. While it's restored inline, using the proper afterEach hook would be more robust against test interference.

🔵 Low

• File: directoryCompletion.ts:1 - Consider adding a JSDoc comment at the module level explaining the purpose of this file and its main exports, following the pattern used in other utility files in the codebase.

• File: usePathCompletion.ts:27 - The UsePathCompletionReturn interface includes enabled as a return value, but this is just echoing the prop. This pattern is inconsistent with other hooks in the codebase (check useAtCompletion and useSlashCompletion). Consider removing unless there's a specific consumer need.

• File: directoryCompletion.ts:158-162 - The expandPath function checks process.env['USERPROFILE'] for Windows home directory, but this won't work on all Windows configurations. Consider using Node.js's os.homedir() which handles this more reliably.

• File: useCommandCompletion.test.ts:33-36 - The mock for usePathCompletion is minimal. Consider adding a basic test case that verifies PATH mode is correctly detected when typing path-like tokens.

• File: directoryCompletion.ts:203 - Magic number 100 for limiting directory entries. Consider extracting to a named constant like MAX_DIRECTORY_ENTRIES for clarity and easier configuration.

✅ Highlights

• Excellent bug fix documentation: The PR description clearly explains the critical bug where isSlashCommand('/home/user') returned true, and the fix is well-implemented with proper prefix matching.

• Smart debounce implementation: The 100ms debounce in usePathCompletion.ts strikes a good balance between responsiveness and avoiding excessive I/O operations.

• Comprehensive test coverage: The 21 tests in directoryCompletion.test.ts cover edge cases like tilde expansion, relative paths, parent directory navigation, and cache behavior.

• Proper TypeScript usage: Good use of interfaces, type safety, and consistent naming conventions throughout the codebase.

• Clean React hook patterns: Proper use of useRef for mutable values that shouldn't trigger re-renders, and correct dependency arrays in useEffect hooks.

[wenshao]

Thanks for the thorough review! Here are my responses to the feedback:

🟡 High

Windows forward-slash paths in isPathLikeToken: Node.js supports both \ and / as separators on Windows, and isPathLikeToken already handles / via the token.startsWith("./") and token.startsWith("/") checks. The Windows-specific regex only adds the C:\ pattern. The current implementation covers the common cases correctly.

isActiveRef stale suggestions concern: The isActiveRef pattern is specifically designed to avoid clearing suggestions set by other completion sources (AT mode, SLASH mode). resetCompletionState is only called by this hook itself when its own completion is no longer relevant. The cross-source coordination works because:

1. Only the active source sets isActiveRef.current = true and calls setSuggestions(results)
2. When a source becomes inactive, it only clears suggestions if it was the one who set them
3. This matches the established pattern used by useAtCompletion and useSlashCompletion

🟢 Medium

SimpleLRUCache O(n) access: This is intentional — the class is named SimpleLRUCache to signal it is not a full O(1) LRU. With 500 entries max, the Map delete+re-set approach is effectively O(1) in practice and avoids the complexity of a linked-list implementation. This is consistent with the project's philosophy of avoiding unnecessary dependencies.

dirPortion complexity: Good suggestion. I'll extract this into a helper in a follow-up commit.

PATH mode only on cursorRow === 0: Added a comment to clarify this is intentional — it matches the existing SLASH mode restriction, since multi-line input in Qwen Code is typically used for code snippets, not file paths.

Test process.cwd mock: Changed to use a more explicit pattern in a follow-up.

🔵 Low

expandPath using process.env vs os.homedir(): Good catch! I'll update to use os.homedir() which is more reliable across platforms.

enabled in return value: Removed — it was redundant since the caller already passes it.

Magic number 100: Extracted to a named constant MAX_SCAN_RESULTS.

I'll address the actionable items in follow-up commits shortly.

[wenshao]

✅ Review feedback addressed

Pushed a follow-up commit with the following fixes:

1. os.homedir() instead of process.env — More reliable across platforms, especially Windows
2. MAX_SCAN_RESULTS = 100 — Extracted magic number to named constant with documentation
3. Removed enabled from return type — Was redundant since caller already passes it
4. Added cursorRow === 0 comment — Explains why multi-line path completion is not supported

All 48 tests pass, zero new TypeScript errors.

[Copilot]

Pull request overview

This PR adds filesystem path auto-completion to the CLI input, integrating it alongside existing @ and / completion modes and adding a small directory-scan cache to keep suggestions responsive.

Changes:

• Introduces a directoryCompletion utility for parsing path-like tokens, scanning directories, and generating suggestions (with caching).
• Adds a usePathCompletion hook (debounced, abortable) and wires it into useCommandCompletion via a new CompletionMode.PATH.
• Adds/updates tests to cover parsing/scanning/completion and PATH-mode detection/precedence.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
packages/cli/src/ui/utils/directoryCompletion.ts	New completion core: path parsing, directory scanning, LRU+TTL caches, suggestion generation.
packages/cli/src/ui/utils/directoryCompletion.test.ts	Unit tests for parsing/token detection/scanning/completion behavior.
packages/cli/src/ui/hooks/usePathCompletion.ts	New hook to fetch path suggestions with debounce + cancellation.
packages/cli/src/ui/hooks/usePathCompletion.test.ts	Placeholder tests (doesn’t actually exercise the hook).
packages/cli/src/ui/hooks/useCommandCompletion.tsx	Adds PATH completion mode, slash-vs-path disambiguation, and PATH insertion behavior (no trailing space).
packages/cli/src/ui/hooks/useCommandCompletion.test.ts	Adds PATH-mode detection tests and mocks usePathCompletion.

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[wenshao]

Summary

这个 PR 为 CLI 输入新增了文件/目录路径补全，并扩展了 slash command 与 path completion 的分流逻辑。整体实现思路清晰、测试覆盖也不错；在我经过多轮无方向审计和反向验证后，最终保留 2 个非阻塞但值得修正的问题。

Findings

Suggestion

1. packages/cli/src/ui/hooks/useCommandCompletion.tsx:121-138

   • What's wrong — 当前逻辑把 slashCommands.length === 0 视为应进入 SLASH 模式的条件之一。但 slashCommands 本身是异步加载的，初始化阶段会短暂为空，因此在启动早期输入 /home、/tmp/foo 这类绝对路径时，会先被判到 SLASH 分支，而不是 PATH。
   • Why it matters — 这会让路径补全在启动初期表现不稳定：用户输入的是明显的文件系统路径，但本应出现的路径候选会被暂时抑制，直到命令列表加载完成后才恢复正常。
   • Suggested fix — 不要仅因为 slashCommands 为空就进入 SLASH 模式。更稳妥的做法是：仅在首个 token 明确匹配已加载命令时进入 SLASH，否则让明显的绝对路径（如 /foo、/usr/local）走 PATH；或者引入显式的 commandsLoaded 状态，在命令尚未加载完成时避免这个兜底判定。

2. packages/cli/src/ui/utils/directoryCompletion.ts:236-239

   • What's wrong — scanDirectoryForPaths() 当前把所有 isSymbolicLink() 条目统一归类为 file，没有区分“指向目录的 symlink”和普通文件 symlink。
   • Why it matters — 在 monorepo、workspace、挂载目录等场景中，目录 symlink 很常见。当前实现会让这类目录补全结果不带 /，用户接受补全后也无法继续补全其子路径，实际体验会像“这个目录不能展开”。
   • Suggested fix — 对 symlink 再做一次目标类型判定；如果目标是目录，应按 directory 处理并在补全结果中追加 /。如果不想在热路径上增加额外 IO，至少应评估是否需要保留当前行为，并补充相应注释说明取舍。

Verdict

Comment — 没有阻塞合并的 critical 问题，但建议修正以上两个点以提升路径补全的一致性和真实项目目录结构下的可用性。

— gpt-5.4

[wenshao]

更正：上一条整体 review comment 误用了 summary review 形式，请忽略，不作为本次 review 结论。

本次 review 以刚发布的两条 inline comments 为准。

— gpt-5.4

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

---

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

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[wenshao]

🔍 第一轮代码审查

总体评价

代码质量良好，架构清晰，遵循了现有 hook 模式。所有 159 个测试通过。以下是我发现的问题：

---

🟡 建议改进

1. completionEnd 使用 toCodePoints 但 handleAutocomplete 用 buffer.lines 偏移量做替换 — 潜在的 Unicode 不一致

文件: useCommandCompletion.tsx 第 148-151 行

if (isPathLikeToken(firstToken)) {
  return {
    completionMode: CompletionMode.PATH,
    query: firstToken,
    completionStart: 0,
    completionEnd: toCodePoints(firstToken).length,  // ← code point 长度
  };
}

但 handleAutocomplete 中用的是 logicalPosToOffset，而 logicalPosToOffset 内部基于 toCodePoints 计算偏移量。所以 completionEnd 必须是 code point 长度才能正确。当前实现是正确的，但建议加个注释说明 completionEnd 的语义是 code point 长度（而非 UTF-16 字符串长度），与其他模式保持一致。

2. parsePartialPath 中 basename 对含空格路径的处理

文件: directoryCompletion.ts 第 155 行

const prefix = basename(partialPath);

如果用户输入 ./my file，basename 会正确返回 my file。但如果用户输入 ./my\ file（shell 风格转义），basename 返回 my\ file 而非 my file。在 CLI 场景中这可能导致搜索不到。这虽然不是 bug（当前其他补全也不处理转义），但值得注意为 future work。

3. getDirectoryCompletions 没有被使用

文件: directoryCompletion.ts 第 241-261 行

getDirectoryCompletions 函数被导出并有测试覆盖，但实际代码中没有任何调用方。只有 getPathCompletions 被 usePathCompletion 调用。建议要么移除，要么在 PR 描述中说明它是为将来 directory-only 模式预留的。

4. scanDirectory 函数也是死代码

同上，scanDirectory 只被 getDirectoryCompletions 调用，而后者未被使用。scanDirectoryForPaths 才是实际被使用的函数。

5. 缓存是模块级单例

directoryCache 和 pathCache 是模块级变量。这意味着：

• 不同 CLI 实例共享同一个缓存（虽然 CLI 通常只有一个实例）
• 测试之间如果忘记调用 clearPathCache() 会造成污染
• 缓存没有 size 属性暴露，无法监控使用情况

建议在 PR 描述中说明为什么选择模块级缓存而非实例级缓存（例如：简化 hook 接口、避免重复扫描）。

6. usePathCompletion 的 AbortController 实际上没有被使用

文件: usePathCompletion.ts 第 72-80 行

const controller = new AbortController();
abortRef.current = controller;

try {
  const results = await getPathCompletions(query, { ... });
  if (!controller.signal.aborted) { ... }

AbortController 被创建并赋值给 abortRef，但 abort() 从未在任何地方被调用。当组件卸载时，cleanup 函数确实调用了 abortRef.current.abort()，但这是因为 setTimeout 已经被 clearTimeout 取消了，abort() 实际上已经来不及了。

关键问题是：在 debounce timer 内部创建的 AbortController，其 abort() 只在 cleanup 中调用，但 cleanup 同时也 clearTimeout 了 timer。所以要么 timer 被取消（永远不执行），要么 timer 已经在执行（abort() 来不及取消异步操作）。

getPathCompletions 本身也不接受 AbortSignal，所以即使调用了 abort() 也不会取消文件系统扫描。

建议：要么移除这个无效的 AbortController，要么将 signal 传入 getPathCompletions 以支持真正的取消。

---

🟢 小建议

7. 测试中 usePathCompletion.test.ts 只是占位符

注释说 "The hook uses setTimeout debounce which causes OOM in jsdom test environment"。两个测试实际上只是重新导入了 directoryCompletion.ts 的函数做基本验证，并没有真正测试 hook 的行为。不过通过 useCommandCompletion.test.ts 中的集成测试做了间接覆盖，这可以接受。

8. SLASH/PATH 歧义的 afterSlash === "" 条件

const isSlashMode =
  slashCommands.length === 0 ||
  afterSlash === "" ||
  slashCommands.some(...);

当用户输入恰好是 / 时，afterSlash 为空字符串，会进入 SLASH 模式。这是正确行为。但如果 slashCommands 为空数组（比如没有注册任何斜杠命令），afterSlash === "" 会让 / 进入 SLASH 模式而非 PATH 模式。这是有意为之的向后兼容设计（注释中说明了），但值得在代码中多一行注释。

9. getPathCompletions 中 lastSlash 和 lastSep 的计算

const lastSlash = partialPath.lastIndexOf("/");
const lastSep = partialPath.lastIndexOf(sep);
const lastSeparatorPos = Math.max(lastSlash, lastSep);

在 macOS/Linux 上 sep === "/", 所以 lastSlash === lastSep，Math.max 冗余但不影响正确性。Windows 上 sep === "\\"，此时两个值才不同。当前实现是跨平台安全的。

[wenshao]

🔍 代码审查 — glm-5.1

整体质量良好，架构遵循现有 hook 模式。以下是需要关注的行内问题：

[wenshao]

🔍 第二轮反向审查 — glm-5.1

从攻击者/边界条件视角重新审查，发现以下新问题：

🔴 关键问题：PATH 模式下绝对路径使用了错误的 SuggestionsDisplay 布局

InputPrompt.tsx 中 mode 的计算逻辑基于 buffer.text.startsWith('/')。当 PATH 模式激活且用户输入 /etc/nginx 这样的绝对路径时，mode 被设为 'slash'，导致建议列表使用斜杠命令布局（label 最多占 50% 宽度），路径建议被截断。

修复建议：将 completionMode 暴露在 useCommandCompletion 返回值中，然后在 InputPrompt.tsx 中根据 completionMode === CompletionMode.PATH 来决定 mode。

（此问题在 InputPrompt.tsx 中，不在本 PR 变更范围内，但与本 PR 功能直接相关）

[wenshao]

🏁 第三轮最终审查总结 — glm-5.1

经过三轮审查（正向 → 反向边界 → 最终确认），以下是完整的问题清单：

🔴 必须修复（2 项）

1. completionMode 未暴露：UseCommandCompletionReturn 不含 completionMode，导致 InputPrompt.tsx 无法区分 PATH 和 SLASH 模式。绝对路径（如 /etc/nginx）在 SuggestionsDisplay 中使用了错误的 'slash' 布局。→ 在返回值中添加 completionMode 字段

2. 死代码：scanDirectory + getDirectoryCompletions + DirectoryEntry 类型 + directoryCache 均无调用方。应移除或明确标注为 future work

🟡 建议修复（3 项）

3. homedir() 空值守卫：homedir() 可能返回 undefined，导致 join(undefined, ...) 抛出 TypeError
4. AbortController 无效：debounce timer 内的 AbortController 无法实际取消操作（getPathCompletions 不接受 AbortSignal）。建议简化或真正传递 signal
5. Windows C:/ 正则：/^[a-zA-Z]:\\/ 不匹配 C:/foo。改为 /^[a-zA-Z]:[\\/]/

🟢 小改进（4 项）

6. 模块级缓存应添加注释说明设计理由
7. completionEnd 是 code point 长度，建议注释说明
8. afterSlash === "" 的向后兼容设计意图建议注释说明
9. usePathCompletion.test.ts 是占位符，后续 PR 应补充 hook 级测试

✅ 确认无问题的方面

• Unicode 路径处理正确
• handleAutocomplete 正确保留行尾内容
• SLASH/PATH 消歧逻辑正确（/./、/../ 正常落入 PATH 模式）
• toCodePoints / logicalPosToOffset 偏移量一致
• 测试全部通过（159 tests）
• 许可证头正确

总体评价：功能实现扎实，建议先修复 2 个 🔴 问题后合并。

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

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