fix(windows): path handling fixes for Windows

[pschiel]

fixes#10360
fixes#10872
fixes#11042
fixes#11043
fixes#11044
fixes#11045
fixes#10871
fixes#8924
fixes#8567
fixes#7279
fixes#6020

fixes ALL test cases in the test suite running on win32 system

(most likely plus a series of more issues)

partly fixes#9077
possibly fixes#10798
possibly fixes#10716
possibly fixes#10642

Summary

This fix solves a whole series of bugs, resulting from filepath issues with backslashes occuring on Windows.

→ Solution: normalize all internal paths to forward slashes using centralized Filesystem wrappers

Why this works: all win32 shells work with forward slash paths, this is de-facto industry standard (git, vscode, cmake, ... all use this pattern)

Observed issues

❌ git rev-parse --show-toplevel returns E:/x/y forward slash format → worktree/directory mismatch
❌ path.resolve(), path.relative(), realpathSync.native(), realpath (bash) break with git bash paths (various issues)
❌ /d/x within C drive (/c/) results in things like C:\d\x
❌ relative paths not working like expected using cross-drive
❌ contains logic not working → issues with permission system and external_directory
❌ /tmp inside git bash is something else outside of it
❌ tools break using backslash paths (some backslashes get "eaten")
❌ escaping hell for agents → requires double/quadruple escaping
❌ observed in all win32 native shells (git bash, cmd, powershell/pwsh)
❌ few issues in app/desktop (wrong filepath splits/usage)
❌ bun hard crashing with segfault when spawn() is used with non-existing directory

Tested with fix

✅ local test suite succeeds now with 100% (bun test in packages/opencode)
✅ all possible path variants (C:\a\b, C:/a/b, /c/a/b, /cygdrive/c/a/b) are normalized into C:/a/b format
✅ full functionality of all tools (ENOENT errors gone, permissions, relative paths, external directory, LSP)
✅ worktree/sandbox handling correct
✅ tested TUI and desktop
✅ bun spawns via bash/pty not segfaulting

How to reproduce/test

• test suite
• running prompts with various problematic/mixed filepaths (see attached md example)

Notes

A few more places would require normalization - but they're unused/dead code (should be removed):

• packages/ui/src/context/sync.tsx line 16 absolute()
• packages/ui/src/context/local.tsx line 392, 420, 455, 546 - file tree operations (no file tree used)

[github-actions]

Hey! Your PR title (feat) support MSYS forward slashes with experimental flag doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[Hona]

This sounds perfect @pschiel

If you can get it ready and finish the cleanup you said I can test and approve.

Btw don't put it behind an experimental flag. We'll ship once it's working.

[Hona]

fyi this is a symlink.
on windows its disabled by default

enable it with

git config core.symlinks true

then recheckout all the files with

git checkout -- .

obviously that would reset any changes so stash/commit first.
that will fix the typecheck too

[pschiel]

was intentional, as this requires admin permissions on windows.

thoughts: changing symlink into export statement in 2 files is worth it for that (the other ~70 symlinks are fonts/images and not affected by TS parsing)

[neriousy]

Something like this would've worked keeping as a simlink

/// <reference path="../../ui/src/custom-elements.d.ts" />

[pschiel]

@neriousy I went by this https://typescript-eslint.io/rules/triple-slash-reference/ which mentions triple slash being discouraged in modern ES6, and a rule for it.

please feel free to change, it was just so typecheck and tests run without errors, in a win32 environment

[pschiel]

Can't reproduce that unicode fail. Ran tests on git bash, powershell and in a Debian container, all passed 🤔

[Hona]

Yup definitely get the whole need for bash compatible paths at all times, give me a sec to investigate impl details and options

[pschiel]

added fixes to avoid bun hard crashing (segfaulting) when invalid cwd is passed

[pschiel]

issues with added prompt test: BunProc.install() hangs in Windows and runs into the timeout -> added Mock in test
d997822382d0b66059c0b0f4bfb56cac331fd775

[edemaine]

Just bumped into this and hope it can be finalized! I made some similar changes in #13671 and #13659 but happy to see you got all the way to 0 errors. I think most of #13659 is still relevant for Cygwin support, but I can review it once this gets merged. Anyway, let me know if I can help.

[pschiel]

Just bumped into this and hope it can be finalized! I made some similar changes in #13671 and #13659 but happy to see you got all the way to 0 errors. I think most of #13659 is still relevant for Cygwin support, but I can review it once this gets merged. Anyway, let me know if I can help.

they apparently prefer their own thing, closing this one - getting no replies since december. despite all the things clearly broken.
dropped using opencode due to this, someone else needs to continue - patch shows what needs to be fixed and how.

[tppawelgrzesik]

@Hona@adamdotdevin@neriousy so is this being worked on elsewhere?

I saw some PRs merged regarding Windows path handling but as of Windows App/Web 1.2.20 change detection / review is still completely broken, eg. always stays empty.

[Hona]

Yes it's nots far off

[tppawelgrzesik]

@Hona alright thanks. I really hope this comes sometime soon.

As of today it's still not working properly.