feat: add porcelain worktree parser with listWorktrees and parseWorktreeListPorcelain

Introduce git worktree list --porcelain parsing following upstream opencode patterns. Exports listWorktrees() for full worktree enumeration with branch info alongside existing detectWorktreePath().

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/start-work/index.ts

@@ -1,4 +1,4 @@
 export { HOOK_NAME, createStartWorkHook } from "./start-work-hook"
-export { detectWorktreePath } from "./worktree-detector"
+export { detectWorktreePath, listWorktrees, parseWorktreeListPorcelain } from "./worktree-detector"
 export type { ParsedUserRequest } from "./parse-user-request"
 export { parseUserRequest } from "./parse-user-request"

src/hooks/start-work/worktree-detector.test.ts

@@ -2,7 +2,7 @@
 
 import { describe, expect, test, spyOn, beforeEach, afterEach } from "bun:test"
 import * as childProcess from "node:child_process"
-import { detectWorktreePath } from "./worktree-detector"
+import { detectWorktreePath, parseWorktreeListPorcelain, listWorktrees } from "./worktree-detector"
 
 describe("detectWorktreePath", () => {
   let execFileSyncSpy: ReturnType<typeof spyOn>
@@ -77,3 +77,113 @@ describe("detectWorktreePath", () => {
     })
   })
 })
+
+describe("parseWorktreeListPorcelain", () => {
+  test("#given porcelain output with multiple worktrees #when parsing #then returns all entries", () => {
+    // given
+    const output = [
+      "worktree /home/user/main-repo",
+      "HEAD abc1234",
+      "branch refs/heads/main",
+      "",
+      "worktree /home/user/worktrees/feature-a",
+      "HEAD def5678",
+      "branch refs/heads/feature-a",
+      "",
+    ].join("\n")
+
+    // when
+    const result = parseWorktreeListPorcelain(output)
+
+    // then
+    expect(result).toEqual([
+      { path: "/home/user/main-repo", branch: "main", bare: false },
+      { path: "/home/user/worktrees/feature-a", branch: "feature-a", bare: false },
+    ])
+  })
+
+  test("#given bare worktree #when parsing #then marks bare flag", () => {
+    // given
+    const output = [
+      "worktree /home/user/bare-repo",
+      "HEAD abc1234",
+      "bare",
+      "",
+    ].join("\n")
+
+    // when
+    const result = parseWorktreeListPorcelain(output)
+
+    // then
+    expect(result).toEqual([
+      { path: "/home/user/bare-repo", branch: undefined, bare: true },
+    ])
+  })
+
+  test("#given empty output #when parsing #then returns empty array", () => {
+    expect(parseWorktreeListPorcelain("")).toEqual([])
+  })
+
+  test("#given output without trailing newline #when parsing #then still captures last entry", () => {
+    // given
+    const output = [
+      "worktree /repo",
+      "HEAD abc1234",
+      "branch refs/heads/dev",
+    ].join("\n")
+
+    // when
+    const result = parseWorktreeListPorcelain(output)
+
+    // then
+    expect(result).toEqual([
+      { path: "/repo", branch: "dev", bare: false },
+    ])
+  })
+})
+
+describe("listWorktrees", () => {
+  let execFileSyncSpy: ReturnType<typeof spyOn>
+
+  beforeEach(() => {
+    execFileSyncSpy = spyOn(childProcess, "execFileSync").mockImplementation(
+      ((_file: string, _args: string[]) => "") as typeof childProcess.execFileSync,
+    )
+  })
+
+  afterEach(() => {
+    execFileSyncSpy.mockRestore()
+  })
+
+  test("#given valid git repo #when listing #then returns parsed worktree entries", () => {
+    // given
+    execFileSyncSpy.mockImplementation(
+      ((_file: string, _args: string[]) =>
+        "worktree /repo\nHEAD abc\nbranch refs/heads/main\n\n") as typeof childProcess.execFileSync,
+    )
+
+    // when
+    const result = listWorktrees("/repo")
+
+    // then
+    expect(result).toEqual([{ path: "/repo", branch: "main", bare: false }])
+    expect(execFileSyncSpy).toHaveBeenCalledWith(
+      "git",
+      ["worktree", "list", "--porcelain"],
+      expect.objectContaining({ cwd: "/repo" }),
+    )
+  })
+
+  test("#given non-git directory #when listing #then returns empty array", () => {
+    // given
+    execFileSyncSpy.mockImplementation((_file: string, _args: string[]) => {
+      throw new Error("not a git repository")
+    })
+
+    // when
+    const result = listWorktrees("/tmp/not-a-repo")
+
+    // then
+    expect(result).toEqual([])
+  })
+})

src/hooks/start-work/worktree-detector.ts

@@ -1,5 +1,68 @@
 import { execFileSync } from "node:child_process"
 
+export type WorktreeEntry = {
+  path: string
+  branch: string | undefined
+  bare: boolean
+}
+
+export function parseWorktreeListPorcelain(output: string): WorktreeEntry[] {
+  const lines = output.split("\n").map((line) => line.trim())
+  const entries: WorktreeEntry[] = []
+  let current: Partial<WorktreeEntry> | undefined
+
+  for (const line of lines) {
+    if (!line) {
+      if (current?.path) {
+        entries.push({
+          path: current.path,
+          branch: current.branch,
+          bare: current.bare ?? false,
+        })
+      }
+      current = undefined
+      continue
+    }
+
+    if (line.startsWith("worktree ")) {
+      current = { path: line.slice("worktree ".length).trim() }
+      continue
+    }
+
+    if (!current) continue
+
+    if (line.startsWith("branch ")) {
+      current.branch = line.slice("branch ".length).trim().replace(/^refs\/heads\//, "")
+    } else if (line === "bare") {
+      current.bare = true
+    }
+  }
+
+  if (current?.path) {
+    entries.push({
+      path: current.path,
+      branch: current.branch,
+      bare: current.bare ?? false,
+    })
+  }
+
+  return entries
+}
+
+export function listWorktrees(directory: string): WorktreeEntry[] {
+  try {
+    const output = execFileSync("git", ["worktree", "list", "--porcelain"], {
+      cwd: directory,
+      encoding: "utf-8",
+      timeout: 5000,
+      stdio: ["pipe", "pipe", "pipe"],
+    })
+    return parseWorktreeListPorcelain(output)
+  } catch {
+    return []
+  }
+}
+
 export function detectWorktreePath(directory: string): string | null {
   try {
     return execFileSync("git", ["rev-parse", "--show-toplevel"], {