fix(cc-watcher): stop burning 65k inotify watches on the plugin cache

`plugins` sat in WATCH_SUBDIRS, so it got fs.watch({recursive:true}). On Linux that's a userland tree walk costing ONE inotify watch per directory, and ~/.claude/plugins is the plugin cache: full git checkouts with node_modules, 44k+ directories. The dashboard process held 65,464 watches against the default fs.inotify.max_user_watches of 65536, leaving none for systemd/IBus — IBus exited on boot and Unikey died with it. Config Explorer only reads two top-level files out of that tree (installed_plugins.json, known_marketplaces.json), so watch plugins/ flat: 1 watch instead of 44k. The small config subdirs stay recursive. Measured on the running service: 65,464 -> 96 watches, and touching installed_plugins.json still broadcasts cc_config_changed.
2026-09-07 08:32:19 +07:00
parent 3223c8edac
commit ae9b3dbcd5
2 changed files with 89 additions and 3 deletions
@@ -0,0 +1,73 @@
+/**
+ * @file Unit tests for cc-watcher's inotify budget. Node's recursive fs.watch is
+ * a userland tree walk on Linux that costs one inotify watch per directory, so
+ * recursively watching ~/.claude/plugins (plugin cache: git checkouts with
+ * node_modules) exhausted fs.inotify.max_user_watches and starved the desktop.
+ * These tests pin which watched subdirs may be recursive.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const { describe, it, beforeEach, afterEach } = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("fs");
+const path = require("path");
+const os = require("os");
+
+let tmpHome;
+let realWatch;
+let calls;
+
+describe("cc-watcher inotify budget", () => {
+  beforeEach(() => {
+    tmpHome = fs.mkdtempSync(path.join(os.tmpdir(), "cc-watcher-"));
+    process.env.CLAUDE_HOME = tmpHome;
+    for (const d of ["agents", "commands", "skills", "output-styles", "hooks", "plugins"]) {
+      fs.mkdirSync(path.join(tmpHome, d), { recursive: true });
+    }
+    // The real shape that caused the leak: a deep tree under plugins/.
+    fs.mkdirSync(path.join(tmpHome, "plugins", "cache", "x", "y", "node_modules", "z"), {
+      recursive: true,
+    });
+
+    calls = [];
+    realWatch = fs.watch;
+    fs.watch = (target, opts, cb) => {
+      calls.push({ target, recursive: !!(opts && opts.recursive) });
+      return realWatch(
+        target,
+        typeof opts === "function" ? {} : opts,
+        typeof opts === "function" ? opts : cb
+      );
+    };
+    delete require.cache[require.resolve("../lib/cc-watcher")];
+    delete require.cache[require.resolve("../lib/claude-home")];
+  });
+
+  afterEach(() => {
+    require("../lib/cc-watcher").stopCcWatcher();
+    fs.watch = realWatch;
+    delete process.env.CLAUDE_HOME;
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+  });
+
+  it("never watches plugins/ recursively", () => {
+    require("../lib/cc-watcher").startCcWatcher({ broadcast: () => {} });
+    const pluginsWatches = calls.filter((c) => c.target === path.join(tmpHome, "plugins"));
+    assert.equal(pluginsWatches.length, 1, "plugins/ should get exactly one watch");
+    assert.equal(pluginsWatches[0].recursive, false, "plugins/ must not be watched recursively");
+  });
+
+  it("still watches plugins/ so its top-level config files fire", () => {
+    require("../lib/cc-watcher").startCcWatcher({ broadcast: () => {} });
+    assert.ok(calls.some((c) => c.target === path.join(tmpHome, "plugins")));
+  });
+
+  it("keeps recursion for the small config subdirs", () => {
+    require("../lib/cc-watcher").startCcWatcher({ broadcast: () => {} });
+    for (const sub of ["agents", "commands", "skills", "output-styles", "hooks"]) {
+      const w = calls.find((c) => c.target === path.join(tmpHome, sub));
+      assert.ok(w, `${sub} should be watched`);
+      assert.equal(w.recursive, true, `${sub} should stay recursive`);
+    }
+  });
+});