feat: improve file watcher with chokidar and better ignore patterns (#2621)

Co-authored-by: GitHub Action <action@github.com>

packages/opencode/src/file/watcher.ts

@@ -0,0 +1,61 @@
+import z from "zod/v4"
+import { Bus } from "../bus"
+import chokidar from "chokidar"
+import { Flag } from "../flag/flag"
+import { Instance } from "../project/instance"
+import { Log } from "../util/log"
+import { FileIgnore } from "./ignore"
+import { Config } from "../config/config"
+
+export namespace FileWatcher {
+  const log = Log.create({ service: "file.watcher" })
+
+  export const Event = {
+    Updated: Bus.event(
+      "file.watcher.updated",
+      z.object({
+        file: z.string(),
+        event: z.union([z.literal("add"), z.literal("change"), z.literal("unlink")]),
+      }),
+    ),
+  }
+
+  const state = Instance.state(
+    async () => {
+      if (Instance.project.vcs !== "git") return {}
+      log.info("init")
+      const cfg = await Config.get()
+      const ignore = (cfg.watcher?.ignore ?? []).map((v) => new Bun.Glob(v))
+      const watcher = chokidar.watch(Instance.directory, {
+        ignoreInitial: true,
+        awaitWriteFinish: true,
+        ignored: (filepath) => {
+          return FileIgnore.match(filepath, {
+            extra: ignore,
+          })
+        },
+      })
+      watcher.on("change", (file) => {
+        Bus.publish(Event.Updated, { file, event: "change" })
+      })
+      watcher.on("add", (file) => {
+        Bus.publish(Event.Updated, { file, event: "add" })
+      })
+      watcher.on("unlink", (file) => {
+        Bus.publish(Event.Updated, { file, event: "unlink" })
+      })
+      watcher.on("ready", () => {
+        log.info("ready")
+      })
+      return { watcher }
+    },
+    async (state) => {
+      state.watcher?.close()
+    },
+  )
+
+  export function init() {
+    if (!Flag.OPENCODE_EXPERIMENTAL_WATCHER) return
+    state()
+  }
+}