Terminal: Windows file links miss backslash relative paths and case- or slash-variant home folders #231

Summary

In the Terminal, Ctrl-click on a Windows-style relative path does nothing, because it isn't detected as a link. Compilers and test runners on Windows print these all the time (src\index.ts:12, .\src\index.ts:12:7, ..\lib\a.ts:3). ~/… paths also fail to expand when the working directory is a Windows home path written in lower case (c:\users\jane\…) or with forward slashes (C:/Users/Jane/…). A quoted path with spaces is cut at the first space.

T3 Code fixed the same parser in pingdotgg/t3code#21199 and #19627. BiBCode's terminal-links.ts has the same patterns they changed.

Current behavior (verified at a0ea849ef92b)

Detection (apps/web/src/terminal-links.ts)

• FILE_PATH_PATTERN at :41-42:

  /(?:~\/|\.{1,2}\/|\/|[A-Za-z]:[\\/]|\\\\)[^\s"'`<>]+|[A-Za-z0-9._-]+(?:\/[A-Za-z0-9._-]+)+(?::\d+){0,2}/g

  The ~, ./ and ../ prefixes and the bare relative form (dir/file) accept only /. Drive-letter paths (C:\…, C:/…) and UNC paths already work.
• The file is imported by the find projection worker (file header), so it has to stay dependency-free.
• The link provider is registered in apps/web/src/components/ThreadTerminalPanel.tsx:1715.

Resolution

• resolvePathLinkTarget (:381-398) expands ~/ only (not ~\) through inferHomeFromCwd.
• inferHomeFromCwd (:142-160) matches a Windows home with /^([A-Za-z]:\\Users\\[^\\]+)/ at :153. That is case-sensitive (Users) and backslash-only.
• Helpers: isWindowsAbsolutePath (:122-124), isWindowsPathStyle (:130-132), joinPath (:134-140). packages/shared/src/path.ts:28-32 has a related isAbsoluteHostPath.

Reproduced by running the module at a0ea849ef92b under Node 24 (extractTerminalLinks and resolvePathLinkTarget):

Existing tests – apps/web/src/terminal-links.test.ts: "finds Windows absolute paths with forward slashes" (:62), "expands home paths for macOS, Linux, and Windows cwd styles" (:292), "joins relative Windows paths and trims existing cwd separators" (:305). None of them cover backslash relative paths, ~\, a lower-case or forward-slash Windows home, or quoted paths with spaces.

Steps to reproduce

1. On a Windows environment, open a Terminal in a project.
2. Run echo src\index.ts:12 (or any tool that prints a relative backslash path).
3. Hover and Ctrl-click the path.

Expected: it's underlined and opens src\index.ts at line 12 in the editor.
Actual: it isn't a link. The same happens for .\… and ..\…. ~\… resolves under the working directory instead of the home.

Proposed change

1. Accept both separators in relative forms (as T3 #21199):

   /(?:~[\\/]|\.{1,2}[\\/]|\/|[A-Za-z]:[\\/]|\\\\)[^\s"'`<>]+|[A-Za-z0-9._-]+(?:[\\/][A-Za-z0-9._-]+)+(?::\d+){0,2}/g

2. Quoted paths with spaces. Add a quoted-path pattern that keeps the whole path between matching quotes, plus a :line[:col] suffix inside or outside the quotes. A quoted match wins over a partial unquoted token. Keep the range correct across wrapped rows (resolveWrappedTerminalLinkRange).
3. Home detection, case-insensitive, both slashes (as T3 #19627): /^([A-Za-z]:[\\/]Users[\\/][^\\/]+)/i. Expand ~\ as well as ~/ when the cwd is Windows-style.
4. Relative backslash paths resolve against the cwd with joinPath, the same as / paths today. .\ and ..\ segments are kept as they are, like ./ and ../ today.
5. Keep the module dependency-free.

T3 Code reference (their claims, not measured by us)

• pingdotgg/t3code#21199, "recognize Windows terminal file links" (merged 2026-10-18). They report that src\index.ts:12 and .\src\index.ts:12 didn't match and that "C:\Users\Jane Doe\project\index.ts:12" was cut to C:\Users\Jane. Their fix: the regex above, a QUOTED_FILE_PATH_PATTERN with precedence over partial tokens, ~\ expansion, and it.each cases (src\index.ts:12, .\src\index.ts:12:7, ..\src\index.ts:12, C:\Users\Jane\project\index.ts:12, quoted paths).
• pingdotgg/t3code#19627, "match Windows home paths case-insensitively in file links" (merged 2026-10-18): the home regex above, in packages/shared/src/fileLinks.ts.

Acceptance criteria

• Table-driven unit tests in apps/web/src/terminal-links.test.ts (it.each), run from apps/web with vp test run --project unit src/terminal-links.test.ts:
  • extractTerminalLinks: every row of the table above, plus ..\..\a\b.ts:1:2, src\a.ts:12: (trailing colon trimmed), (src\a.ts:12) (delimiters trimmed), '.\a b\c.ts', a backtick-quoted path, a line with a URL and a backslash path (both found, no overlap), and \\server\share\a.ts (still detected, and still refused as a network path on activation);
  • resolvePathLinkTarget: ~/ and ~\ with C:\Users\Jane\…, c:\users\jane\…, C:/Users/Jane/… and c:/USERS/jane/…; .\src\a.ts:3 and src\a.ts against C:\repo and C:\repo\; POSIX home and relative cases unchanged.
  • With only terminal-links.ts reverted, the new cases fail.
• Wrapped lines: a quoted path with spaces that wraps across two rows maps back to the right buffer range (a resolveWrappedTerminalLinkRange test).
• Existing behavior unchanged: all current terminal-links.test.ts cases, URL detection, file:// handling, OSC 8 links, and the network-path refusal ("Network paths can't be opened from the terminal.").
• Desktop e2e: vp run test:ui:desktop, including apps/desktop/e2e/specs/project-session-terminal.e2e.ts and terminal-font.e2e.ts. If the Windows native desktop job can run a terminal link check, add the src\index.ts:12 case there; otherwise say so in the PR.
• Gates: vp check (zero warnings), vp run typecheck, Release Smoke. No Rust or contract changes are expected; if any appear, cargo fmt --all --check, cargo clippy --workspace --all-targets -- -D warnings, cargo test --workspace and vp run check:contracts too.
• UI.md and vercel-react-best-practices reviews are recorded. docs/testing/ runbooks are reviewed (cross-platform-validation.md:3632-3645, terminal links) and updated or stated "remain accurate".
• Profiler coverage line in the delivery report. Terminal content and paths never reach profiler records or logs.

Living docs to update

• docs/user/workspace-ui.md:1495-1508 (Terminal links): Windows relative paths, ~\, quoted paths with spaces.
• docs/testing/cross-platform-validation.md:3632-3645: add a Windows relative-path row to the manual check.

Not in scope

• Chat and Markdown file links (a different parser).
• Opening network paths; they stay refused.
• Normalizing .\ / ..\ before opening.

Related

• None found in BiBCode's open or closed issues (searched for terminal link, Windows path, backslash).

Open questions

• Should a bare dir\file be linked when the cwd is POSIX? It's a legal but rare filename there; T3 links it everywhere.
• For a forward-slash Windows home (C:/Users/Jane), which separator should the expanded path use? isWindowsPathStyle treats C:/… as Windows style, so joinPath would produce a mixed C:/Users/Jane\x.ts. Keeping the home's own separator seems safer.