fix: resolve Windows path separator inconsistency and make tests OS-independent by flanny7 · Pull Request #1383 · dyoshikawa/rulesync

flanny7 · 2026-03-27T04:21:37Z

Hello,
I always appreciate your work on rulesync.

Following up on Issue #1251 and related Windows path behaviors, I have created a Pull Request to resolve the path separator inconsistency and make the tests OS-independent.

Description

Closes #1251

This PR fixes the Windows path separator inconsistency that caused backslashes (\) to appear in contexts requiring forward slashes (/), and implements OS-independent parameterized tests to ensure cross-platform reliability.

Root Cause

path.join() from node:path uses the platform separator — backslash on Windows. The codebase used path.join() in four non-filesystem contexts that require forward slashes:

.gitignore entries — The gitignore spec requires forward slashes. On Windows, RULESYNC_CURATED_SKILLS_RELATIVE_DIR_PATH resolved to .rulesync\skills\.curated, producing an invalid gitignore entry.
GitHub API paths — fetch.ts used path.join(basePath, featurePath) to build repository paths sent to the GitHub Contents API. On Windows this produced paths like packages\shared\rules, which the API cannot resolve.
Rule file @-references — AiFile.getRelativePathFromCwd() used path.join() to produce display paths that are written verbatim into generated rule files (e.g., @.cursor/rules/sub/my-rule.md in TOON format and Claude Code legacy format). On Windows, when a rule file is in a subdirectory, path.relative() returns sub\my-rule.md, causing getRelativePathFromCwd() to produce @.cursor/rules/sub\my-rule.md — broken syntax.
Directory display paths — AiDir.getRelativePathFromCwd() had the same issue (used for dry-run logging and changed-path reporting).

Affected Components

Component	Impact
`gitignore` command	Generated `.gitignore` contained backslash entries on Windows
`fetch` command	GitHub API requests failed with 404 Not Found on Windows
Non-root rules	`@`-references in generated root rule files contained backslashes on Windows

Changes Made

src/constants/rulesync-paths.ts: Changed path.join to path.posix.join so constants always use forward slashes. When these constants are later used in filesystem operations (e.g., path.join(process.cwd(), constant)), path.join normalizes them to the platform separator automatically.
src/lib/fetch.ts: Changed join(basePath, featurePath) to posix.join(basePath, featurePath) for the GitHub API path construction.
src/types/ai-file.ts & src/types/ai-dir.ts: Added .replace(/\\/g, "/") to getRelativePathFromCwd() so paths written into rule file content always use forward slashes, regardless of what path.join() produces on the host OS.

Testing Strategy & Added Tests

To prevent false positives on macOS/Linux CI runners (where path.join natively returns /), the tests have been designed to be strictly OS-independent:

Parameterized Input Testing (src/types/tool-file.test.ts, src/types/ai-dir.test.ts, src/lib/fetch.test.ts): Instead of destructively mocking node:path, we use it.each to explicitly inject both Windows-style (\\) and POSIX-style (/) path strings. This guarantees that the path sanitization logic works consistently across all platforms without breaking native OS testing capabilities.
Static Constants & Gitignore (src/constants/rulesync-paths.test.ts, src/cli/commands/gitignore.test.ts): Added assertions to verify that dynamically generated constants and gitignore entries never contain backslashes (.not.toContain("\\")). (Any regressions in base paths will be caught by Windows runners in the CI matrix).

Please let me know if there are any formatting issues or if I missed anything in the contribution guidelines. I would be happy to fix them.

There is no rush at all for the review. Your time and consideration are greatly appreciated.

dyoshikawa-claw

The path separator fix looks good overall, but one test case is not actually exercising the parameterized inputs. That makes the OS-independent coverage weaker than intended, so I think this needs one small correction before merging.

dyoshikawa-claw · 2026-03-27T09:48:56Z

+          relativeDirPath: ".cursor/rules",
+          relativeFilePath: "sub\\rule.md",
+          fileContent: "content",
+          validate: false,


This test is parameterized, but the constructor call below still hardcodes the Windows-style input. As written, the POSIX case is not actually being exercised, so the test only covers one path shape.

Copilot

Pull request overview

This PR addresses Windows-specific path separator issues by ensuring forward-slash (POSIX) paths are used in non-filesystem contexts (e.g., gitignore entries, GitHub API paths, and rule-file @ references), and adds OS-independent tests to prevent regressions.

Changes:

Normalize generated “display/reference” paths to use / by replacing backslashes in AiFile/AiDir relative path helpers.
Use path.posix.join for GitHub API path construction and for Rulesync relative-path constants that must remain POSIX.
Add cross-platform tests asserting forward-slash-only outputs for constants, gitignore entries, and fetch API paths.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/types/tool-file.test.ts	Adds parameterized test for forward-slash output (but currently doesn’t apply the table inputs).
src/types/ai-file.ts	Forces `/` in `getRelativePathFromCwd()` output.
src/types/ai-dir.ts	Forces `/` in `getRelativePathFromCwd()` output.
src/types/ai-dir.test.ts	New test coverage for `AiDir.getRelativePathFromCwd()` path separator normalization.
src/lib/fetch.ts	Uses `posix.join` for GitHub Contents API path building.
src/lib/fetch.test.ts	Adds regression test ensuring API paths never contain backslashes.
src/constants/rulesync-paths.ts	Switches Rulesync path constants to `posix.join` to keep `/` on all OSes.
src/constants/rulesync-paths.test.ts	Asserts Rulesync path constants never contain backslashes.
src/cli/commands/gitignore.test.ts	Asserts all gitignore entries are forward-slash-only.

Copilot · 2026-03-27T14:58:30Z

+          relativeDirPath: ".cursor/rules",
+          relativeFilePath: "sub\\rule.md",


The parameterized cases in this it.each aren’t actually applied: the TestToolFile is constructed with hard-coded relativeDirPath and relativeFilePath values, so the Windows/POSIX inputs from the table are ignored. This makes the test pass without exercising the intended cross-platform scenarios. Use the relativeDirPath/relativeFilePath arguments from it.each when constructing TestToolFile (and consider setting baseDir if the constructor requires it).

Suggested change

relativeDirPath: ".cursor/rules",

relativeFilePath: "sub\\rule.md",

baseDir: testDir,

relativeDirPath,

relativeFilePath,

flanny7 · 2026-03-29T13:02:09Z

Thank you for the review.

I fixed the issue in src/types/tool-file.test.ts with the following changes:

Parameter Fix: The it.each parameters (relativeDirPath and relativeFilePath) were declared but not passed to the TestToolFile constructor.
Logical Update: Updated the constructor to use these parameterized inputs instead of hardcoded values.
Environment Support: Added baseDir: testDir so that both Windows-style (\) and POSIX-style (/) paths are now independently exercised.

GitHub API and .gitignore entries require forward slashes, but path.join() produces backslashes on Windows. This caused fetch command failures with subdirectory paths and gitignore entries with mixed separators. Changes: - src/constants/rulesync-paths.ts: Use path.posix.join to ensure constants always contain forward slashes. When used in filesystem operations (e.g., join(cwd, constant)), path.join automatically normalizes to platform separators. - src/lib/fetch.ts: Use posix.join for GitHub API path construction instead of platform-dependent join. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Add tests verifying that: - rulesync-paths constants always use forward slashes - .gitignore entries use only forward slashes - GitHub API paths never contain backslashes These tests catch Windows path separator issues that would break fetch and gitignore commands on Windows systems. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Normalize backslashes to forward slashes in AiFile.getRelativePathFromCwd() and AiDir.getRelativePathFromCwd(). These methods produce paths that are written into generated rule file content (e.g., @.cursor/rules/my-rule.md) via rules-processor.ts. On Windows, when rules are in subdirectories, path.relative() returns backslash-separated paths, causing getRelativePathFromCwd() to produce paths with backslashes—invalid syntax for rule files. The fix applies .replace(/\\/g, "/") to normalize the output, ensuring cross-platform consistency regardless of the host OS. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Add tests to verify that getRelativePathFromCwd() normalizes backslashes to forward slashes: - tool-file.test.ts: Test AiFile.getRelativePathFromCwd() with backslash in relativeFilePath (simulating Windows path.relative() output) - ai-dir.test.ts (new): Test AiDir.getRelativePathFromCwd() with backslash in relativeDirPath Both tests verify that the return value never contains backslashes, ensuring paths written into rule file content are always cross-platform compatible. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Replaced host-OS-dependent path tests with `it.each` blocks that explicitly test both Windows-style and POSIX-style path inputs. This prevents false positives on macOS/Linux CI runners and ensures path sanitization logic is robust without destructively mocking `node:path`.

Fix it.each test in tool-file.test.ts that declared relativeDirPath and relativeFilePath parameters but hardcoded values in the TestToolFile constructor, making the Windows-style path case never actually exercised. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dyoshikawa · 2026-03-30T04:22:35Z

@flanny7 Thank you!

- Add explanatory comments in ai-file.ts and ai-dir.ts for why .replace() is used instead of path.posix.join (#1) - Improve fetch.test.ts with parameterized Windows-style backslash path test inputs via it.each (#2) - Normalize backslashes in fetch.ts resolvedPath for API compatibility - Update coding-guidelines.md to distinguish filesystem paths (path.join) from semantic/API paths (path.posix.join) (#3) Closes #1394 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fix: address review findings from PR #1383 Windows path separator fix

flanny7 force-pushed the fix/path-backslash branch from 74eea7f to 02a51e4 Compare March 27, 2026 04:25

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dyoshikawa-claw reviewed Mar 27, 2026

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dyoshikawa requested a review from Copilot March 27, 2026 14:55

Copilot started reviewing on behalf of dyoshikawa March 27, 2026 14:55 View session

Copilot AI reviewed Mar 27, 2026

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flanny7 and others added 7 commits March 29, 2026 22:02

style: apply oxfmt to test files

f96c15e

flanny7 force-pushed the fix/path-backslash branch from 697d957 to 28a23fe Compare March 29, 2026 13:02

dyoshikawa mentioned this pull request Mar 30, 2026

Review findings from PR #1383: Windows path separator fix #1394

Closed

dyoshikawa merged commit d0a3241 into dyoshikawa:main Mar 30, 2026
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dyoshikawa mentioned this pull request Mar 30, 2026

fix: address review findings from PR #1383 Windows path separator fix #1398

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dyoshikawa added a commit that referenced this pull request Mar 31, 2026

Merge pull request #1398 from dyoshikawa/issue-1394

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fix: address review findings from PR #1383 Windows path separator fix

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fix: resolve Windows path separator inconsistency and make tests OS-independent#1383

fix: resolve Windows path separator inconsistency and make tests OS-independent#1383
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		relativeDirPath: ".cursor/rules",
		relativeFilePath: "sub\\rule.md",

-          relativeDirPath: ".cursor/rules",
-          relativeFilePath: "sub\\rule.md",
+          baseDir: testDir,
+          relativeDirPath,
+          relativeFilePath,

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flanny7 commented Mar 27, 2026

Description

Root Cause

Affected Components

Changes Made

Testing Strategy & Added Tests

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