enable parcel file watcher, expand parcel ignore patterns, replace fs watcher for git branches with parcel (#4805)

packages/opencode/src/project/project.ts

@@ -12,6 +12,7 @@ export namespace Project {
     .object({
       id: z.string(),
       worktree: z.string(),
+      vcsDir: z.string().optional(),
       vcs: z.literal("git").optional(),
       time: z.object({
         created: z.number(),
@@ -80,9 +81,16 @@ export namespace Project {
       .cwd(worktree)
       .text()
       .then((x) => x.trim())
+    const vcsDir = await $`git rev-parse --path-format=absolute --git-dir`
+      .quiet()
+      .nothrow()
+      .cwd(worktree)
+      .text()
+      .then((x) => x.trim())
     const project: Info = {
       id,
       worktree,
+      vcsDir,
       vcs: "git",
       time: {
         created: Date.now(),

packages/opencode/src/project/vcs.ts

@@ -1,10 +1,10 @@
 import { $ } from "bun"
-import { watch, type FSWatcher } from "fs"
 import path from "path"
 import z from "zod"
 import { Log } from "@/util/log"
 import { Bus } from "@/bus"
 import { Instance } from "./instance"
+import { FileWatcher } from "@/file/watcher"
 
 const log = Log.create({ service: "vcs" })
 
@@ -39,49 +39,31 @@ export namespace Vcs {
 
   const state = Instance.state(
     async () => {
-      if (Instance.project.vcs !== "git") {
-        return { branch: async () => undefined, watcher: undefined }
+      const vcsDir = Instance.project.vcsDir
+      if (Instance.project.vcs !== "git" || !vcsDir) {
+        return { branch: async () => undefined, unsubscribe: undefined }
       }
       let current = await currentBranch()
       log.info("initialized", { branch: current })
 
-      const gitDir = await $`git rev-parse --git-dir`
-        .quiet()
-        .nothrow()
-        .cwd(Instance.worktree)
-        .text()
-        .then((x) => x.trim())
-        .catch(() => undefined)
-      if (!gitDir) {
-        log.warn("failed to resolve git directory")
-        return { branch: async () => current, watcher: undefined }
-      }
-
-      const gitHead = path.join(gitDir, "HEAD")
-      let watcher: FSWatcher | undefined
-      // we should probably centralize file watching (see watcher.ts)
-      // but parcel still marked experimental rn
-      try {
-        watcher = watch(gitHead, async () => {
-          const next = await currentBranch()
-          if (next !== current) {
-            log.info("branch changed", { from: current, to: next })
-            current = next
-            Bus.publish(Event.BranchUpdated, { branch: next })
-          }
-        })
-        log.info("watching", { path: gitHead })
-      } catch (e) {
-        log.warn("failed to watch git HEAD", { error: e })
-      }
+      const head = path.join(vcsDir, "HEAD")
+      const unsubscribe = Bus.subscribe(FileWatcher.Event.Updated, async (evt) => {
+        if (evt.properties.file !== head) return
+        const next = await currentBranch()
+        if (next !== current) {
+          log.info("branch changed", { from: current, to: next })
+          current = next
+          Bus.publish(Event.BranchUpdated, { branch: next })
+        }
+      })
 
       return {
         branch: async () => current,
-        watcher,
+        unsubscribe,
       }
     },
     async (state) => {
-      state.watcher?.close()
+      state.unsubscribe?.()
     },
   )