Hermes-agent

apps/desktop/electron/git-worktrees.cjs

@@ -0,0 +1,174 @@
+'use strict'
+
+// Resolve git-worktree relationships for a set of session cwds, reading git's
+// on-disk metadata directly (no `git` spawn per path):
+//
+//   - A normal checkout has a `.git` DIRECTORY at its root → it's the main
+//     worktree; its repo root IS that directory's parent.
+//   - A linked worktree has a `.git` FILE: `gitdir: <repo>/.git/worktrees/<name>`.
+//     That admin dir's `commondir` points back at the shared `<repo>/.git`, whose
+//     parent is the main repo root.
+//
+// Grouping by repoRoot therefore clusters a repo's main checkout with all of its
+// linked worktrees, regardless of how the worktree directories are named. The
+// branch (read from the worktree's own HEAD) gives each worktree a meaningful
+// label.
+
+const fs = require('node:fs')
+const path = require('node:path')
+const { resolveRequestedPathForIpc } = require('./hardening.cjs')
+
+// Walk up from `start` to the nearest ancestor that carries a `.git` entry
+// (file for a linked worktree, dir for the main checkout). Capped so a stray
+// path can't loop forever.
+function findGitHost(start, fsImpl) {
+  let dir = start
+
+  for (let i = 0; i < 64; i += 1) {
+    const dotgit = path.join(dir, '.git')
+
+    try {
+      if (fsImpl.existsSync(dotgit)) {
+        return dir
+      }
+    } catch {
+      return null
+    }
+
+    const parent = path.dirname(dir)
+
+    if (parent === dir) {
+      return null
+    }
+
+    dir = parent
+  }
+
+  return null
+}
+
+function readBranch(gitDir, fsImpl) {
+  try {
+    const head = fsImpl.readFileSync(path.join(gitDir, 'HEAD'), 'utf8').trim()
+    const ref = head.match(/^ref:\s*refs\/heads\/(.+)$/)
+
+    if (ref) {
+      return ref[1]
+    }
+
+    // Detached HEAD: surface a short sha so the worktree still gets a label.
+    return /^[0-9a-f]{7,40}$/i.test(head) ? head.slice(0, 8) : null
+  } catch {
+    return null
+  }
+}
+
+// Given the directory that owns the `.git` entry, resolve its worktree identity.
+function resolveFromHost(host, fsImpl) {
+  const dotgit = path.join(host, '.git')
+  let stat
+
+  try {
+    stat = fsImpl.statSync(dotgit)
+  } catch {
+    return null
+  }
+
+  if (stat.isDirectory()) {
+    return {
+      repoRoot: host,
+      worktreeRoot: host,
+      isMainWorktree: true,
+      branch: readBranch(dotgit, fsImpl)
+    }
+  }
+
+  // Linked worktree: `.git` is a file pointing at the admin dir.
+  let contents
+
+  try {
+    contents = fsImpl.readFileSync(dotgit, 'utf8').trim()
+  } catch {
+    return null
+  }
+
+  const match = contents.match(/^gitdir:\s*(.+)$/m)
+
+  if (!match) {
+    return null
+  }
+
+  const adminDir = path.resolve(host, match[1].trim())
+
+  // `commondir` resolves to the shared `<repo>/.git`; fall back to walking two
+  // levels up from `<repo>/.git/worktrees/<name>` if it's missing.
+  let commonDir
+
+  try {
+    const rel = fsImpl.readFileSync(path.join(adminDir, 'commondir'), 'utf8').trim()
+    commonDir = path.resolve(adminDir, rel)
+  } catch {
+    commonDir = path.dirname(path.dirname(adminDir))
+  }
+
+  return {
+    repoRoot: path.dirname(commonDir),
+    worktreeRoot: host,
+    isMainWorktree: false,
+    branch: readBranch(adminDir, fsImpl)
+  }
+}
+
+function resolveWorktree(startPath, fsImpl = fs) {
+  let resolved
+
+  try {
+    resolved = resolveRequestedPathForIpc(startPath, { purpose: 'Worktree lookup' })
+  } catch {
+    return null
+  }
+
+  let start = resolved
+
+  try {
+    const stat = fsImpl.statSync(resolved)
+
+    if (!stat.isDirectory()) {
+      start = path.dirname(resolved)
+    }
+  } catch {
+    return null
+  }
+
+  const host = findGitHost(start, fsImpl)
+
+  if (!host) {
+    return null
+  }
+
+  return resolveFromHost(host, fsImpl)
+}
+
+// Batch entry point for the renderer: maps each requested cwd to its worktree
+// info (or null when it isn't inside a git checkout / can't be read). Dedupes so
+// many sessions sharing a cwd cost one lookup.
+async function worktreesForIpc(cwds, options = {}) {
+  const fsImpl = options.fs || fs
+  const list = Array.isArray(cwds) ? cwds : []
+  const out = {}
+
+  for (const cwd of list) {
+    if (typeof cwd !== 'string' || !cwd.trim() || cwd in out) {
+      continue
+    }
+
+    out[cwd] = resolveWorktree(cwd, fsImpl)
+  }
+
+  return out
+}
+
+module.exports = {
+  resolveWorktree,
+  worktreesForIpc
+}