fix(windows): git path resolution for modified files across Git Bash, MSYS2, and Cygwin (#16422)

packages/opencode/test/config/config.test.ts

@@ -25,6 +25,34 @@ async function writeConfig(dir: string, config: object, name = "opencode.json")
   await Filesystem.write(path.join(dir, name), JSON.stringify(config))
 }
 
+async function check(map: (dir: string) => string) {
+  if (process.platform !== "win32") return
+  await using globalTmp = await tmpdir()
+  await using tmp = await tmpdir({ git: true, config: { snapshot: true } })
+  const prev = Global.Path.config
+  ;(Global.Path as { config: string }).config = globalTmp.path
+  Config.global.reset()
+  try {
+    await writeConfig(globalTmp.path, {
+      $schema: "https://opencode.ai/config.json",
+      snapshot: false,
+    })
+    await Instance.provide({
+      directory: map(tmp.path),
+      fn: async () => {
+        const cfg = await Config.get()
+        expect(cfg.snapshot).toBe(true)
+        expect(Instance.directory).toBe(Filesystem.resolve(tmp.path))
+        expect(Instance.project.id).not.toBe("global")
+      },
+    })
+  } finally {
+    await Instance.disposeAll()
+    ;(Global.Path as { config: string }).config = prev
+    Config.global.reset()
+  }
+}
+
 test("loads config with defaults when no files exist", async () => {
   await using tmp = await tmpdir()
   await Instance.provide({
@@ -56,6 +84,23 @@ test("loads JSON config file", async () => {
   })
 })
 
+test("loads project config from Git Bash and MSYS2 paths on Windows", async () => {
+  // Git Bash and MSYS2 both use /<drive>/... paths on Windows.
+  await check((dir) => {
+    const drive = dir[0].toLowerCase()
+    const rest = dir.slice(2).replaceAll("\\", "/")
+    return `/${drive}${rest}`
+  })
+})
+
+test("loads project config from Cygwin paths on Windows", async () => {
+  await check((dir) => {
+    const drive = dir[0].toLowerCase()
+    const rest = dir.slice(2).replaceAll("\\", "/")
+    return `/cygdrive/${drive}${rest}`
+  })
+})
+
 test("ignores legacy tui keys in opencode config", async () => {
   await using tmp = await tmpdir({
     init: async (dir) => {

packages/opencode/test/util/filesystem.test.ts

@@ -440,4 +440,67 @@ describe("filesystem", () => {
       expect(await fs.readFile(filepath, "utf-8")).toBe(content)
     })
   })
+
+  describe("resolve()", () => {
+    test("resolves slash-prefixed drive paths on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const forward = tmp.path.replaceAll("\\", "/")
+      expect(Filesystem.resolve(`/${forward}`)).toBe(Filesystem.normalizePath(tmp.path))
+    })
+
+    test("resolves slash-prefixed drive roots on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toUpperCase()
+      expect(Filesystem.resolve(`/${drive}:`)).toBe(Filesystem.resolve(`${drive}:/`))
+    })
+
+    test("resolves Git Bash and MSYS2 paths on Windows", async () => {
+      // Git Bash and MSYS2 both use /<drive>/... paths on Windows.
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      const rest = tmp.path.slice(2).replaceAll("\\", "/")
+      expect(Filesystem.resolve(`/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+    })
+
+    test("resolves Git Bash and MSYS2 drive roots on Windows", async () => {
+      // Git Bash and MSYS2 both use /<drive> paths on Windows.
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      expect(Filesystem.resolve(`/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+    })
+
+    test("resolves Cygwin paths on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      const rest = tmp.path.slice(2).replaceAll("\\", "/")
+      expect(Filesystem.resolve(`/cygdrive/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+    })
+
+    test("resolves Cygwin drive roots on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      expect(Filesystem.resolve(`/cygdrive/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+    })
+
+    test("resolves WSL mount paths on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      const rest = tmp.path.slice(2).replaceAll("\\", "/")
+      expect(Filesystem.resolve(`/mnt/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+    })
+
+    test("resolves WSL mount roots on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+      const drive = tmp.path[0].toLowerCase()
+      expect(Filesystem.resolve(`/mnt/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+    })
+  })
 })

packages/opencode/test/util/which.test.ts

@@ -22,6 +22,13 @@ function env(PATH: string): NodeJS.ProcessEnv {
   }
 }
 
+function envPath(Path: string): NodeJS.ProcessEnv {
+  return {
+    Path,
+    PathExt: process.env["PathExt"] ?? process.env["PATHEXT"],
+  }
+}
+
 function same(a: string | null, b: string) {
   if (process.platform === "win32") {
     expect(a?.toLowerCase()).toBe(b.toLowerCase())
@@ -79,4 +86,15 @@ describe("util.which", () => {
 
     expect(which("pathext", { PATH: bin, PATHEXT: ".CMD" })).toBe(file)
   })
+
+  test("uses Windows Path casing fallback", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    const bin = path.join(tmp.path, "bin")
+    await fs.mkdir(bin)
+    const file = await cmd(bin, "mixed")
+
+    same(which("mixed", envPath(bin)), file)
+  })
 })