fix(watcher): close deleted opened documents

src/daemon.ts

@@ -5,8 +5,9 @@
 import * as fs from "node:fs";
 import * as net from "node:net";
 import * as path from "node:path";
+import type { FileSystemWatcher } from "vscode-languageserver-protocol";
 import { LspClient } from "./client.ts";
-import { findRoot, findServerById, pathToUri } from "./root.ts";
+import { findRoot, findServerById, pathToUri, uriToPath } from "./root.ts";
 import type { ServerConfig } from "./types.ts";
 import { WorkspaceWatcher, type FileEvent } from "./watcher.ts";
 import {
@@ -21,6 +22,7 @@ import {
 const DEFAULT_IDLE_TTL_MS = 5 * 60 * 1000;
 const WATCHER_READY_TIMEOUT_MS = 5000;
 const FILE_CHANGE_DELETED = 3;
+const WATCH_KIND_DELETE = 4;
 
 // Client Entry - One LspClient per (server.id, rootDir), plus the bookkeeping
 // needed to keep files in sync and evict on idleness.
@@ -110,8 +112,22 @@ async function getOrCreateEntry(
 // Attach Watcher - Registration can happen during initialize, before the daemon subscribes.
 async function attachWatcher(entry: ClientEntry): Promise<void> {
   if (process.env.PI_LSP_DISABLE_WATCHERS) return;
-  const sync = async () => {
-    const patterns = entry.client.getFileWatchers();
+  entry.unsubscribeWatchers = entry.client.onWatchersChanged(() => void refreshWatcher(entry));
+  await refreshWatcher(entry);
+}
+
+function watcherPatterns(entry: ClientEntry): FileSystemWatcher[] {
+  const registered = entry.client.getFileWatchers();
+  const openedDeletes = [...entry.opened.keys()].map((uri) => ({
+    globPattern: uriToPath(uri).split(path.sep).join("/"),
+    kind: WATCH_KIND_DELETE,
+  }));
+  return [...registered, ...openedDeletes];
+}
+
+async function refreshWatcher(entry: ClientEntry): Promise<void> {
+  if (process.env.PI_LSP_DISABLE_WATCHERS) return;
+  const patterns = watcherPatterns(entry);
   if (patterns.length === 0 && !entry.watcher) return;
   if (!entry.watcher) {
     entry.watcher = new WorkspaceWatcher(entry.rootDir, (events) =>
@@ -124,9 +140,6 @@ async function attachWatcher(entry: ClientEntry): Promise<void> {
   }
   entry.watcher.setPatterns(patterns);
   if (patterns.length > 0) await waitForWatcherReady(entry);
-  };
-  entry.unsubscribeWatchers = entry.client.onWatchersChanged(() => void sync());
-  await sync();
 }
 
 async function waitForWatcherReady(entry: ClientEntry): Promise<void> {
@@ -157,6 +170,7 @@ function forwardEvents(entry: ClientEntry, events: FileEvent[]): void {
       if (event.type !== FILE_CHANGE_DELETED || !entry.opened.has(event.uri)) continue;
       entry.client.closeDocument(event.uri);
       entry.opened.delete(event.uri);
+      void refreshWatcher(entry);
     }
     if (process.env.LSP_DEBUG) {
       log(`watcher fire`, entry.server.id, JSON.stringify(events));
@@ -206,6 +220,7 @@ async function syncFile(
     if (prev === undefined) {
       entry.client.openDocument(filePath);
       entry.opened.set(uri, stat.mtimeMs);
+      await refreshWatcher(entry);
       return { uri, changed: true };
     } else if (prev !== stat.mtimeMs) {
       entry.client.notifyChange(filePath);

test/integration/watcher-typescript.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, before, after } from "node:test";
+import * as assert from "node:assert/strict";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+import {
+  setTestSocket,
+  stopTestDaemon,
+  runCliJson,
+  requireServer,
+} from "../helpers.ts";
+
+const skip = requireServer("typescript-language-server");
+
+async function pollUntil<T>(
+  fn: () => Promise<T>,
+  predicate: (v: T) => boolean,
+  timeoutMs: number,
+  intervalMs = 250,
+): Promise<T> {
+  const deadline = Date.now() + timeoutMs;
+  let last: T = await fn();
+  while (Date.now() < deadline) {
+    if (predicate(last)) return last;
+    await new Promise((r) => setTimeout(r, intervalMs));
+    last = await fn();
+  }
+  return last;
+}
+
+interface DiagResult {
+  [serverId: string]: { diagnostics?: { message: string }[] };
+}
+
+describe("watcher: typescript handles deleted opened files", { skip: skip ?? undefined }, () => {
+  let tmpDir: string;
+  let mainFile: string;
+  let helperFile: string;
+  const env = { ...process.env };
+  let cleanup: () => void;
+
+  before(async () => {
+    delete env.NODE_OPTIONS;
+    cleanup = setTestSocket(env);
+    await stopTestDaemon(env);
+
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "pi-lsp-ts-watch-"));
+    fs.writeFileSync(
+      path.join(tmpDir, ".pi-lsp.json"),
+      JSON.stringify({ disable: ["oxlint"] }),
+    );
+    fs.writeFileSync(
+      path.join(tmpDir, "tsconfig.json"),
+      JSON.stringify(
+        {
+          compilerOptions: {
+            target: "ES2022",
+            module: "ESNext",
+            moduleResolution: "Bundler",
+            strict: true,
+            noEmit: true,
+          },
+          include: ["*.ts"],
+        },
+        null,
+        2,
+      ),
+    );
+    mainFile = path.join(tmpDir, "main.ts");
+    helperFile = path.join(tmpDir, "helper.ts");
+    fs.writeFileSync(
+      mainFile,
+      'import { helper } from "./helper";\n\nconsole.log(helper());\n',
+    );
+    fs.writeFileSync(helperFile, "export function helper(): number {\n  return 1;\n}\n");
+  });
+
+  after(async () => {
+    await stopTestDaemon(env);
+    cleanup();
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it("reports missing module after an opened imported file is deleted", async () => {
+    const initial = (await runCliJson(
+      [mainFile, "diagnostics", '{"timeoutMs":5000}'],
+      env,
+    )) as DiagResult;
+    assert.deepEqual(initial["typescript-language-server"]?.diagnostics ?? [], []);
+
+    await runCliJson([helperFile, "diagnostics", '{"timeoutMs":5000}'], env);
+    fs.rmSync(helperFile);
+
+    const result = await pollUntil(
+      async () =>
+        (await runCliJson(
+          [mainFile, "diagnostics", '{"timeoutMs":3000}'],
+          env,
+        )) as DiagResult,
+      (r) => {
+        const diags = r["typescript-language-server"]?.diagnostics ?? [];
+        return diags.some((d) => d.message.includes("Cannot find module './helper'"));
+      },
+      15000,
+      500,
+    );
+
+    const diags = result["typescript-language-server"]?.diagnostics ?? [];
+    assert.ok(
+      diags.some((d) => d.message.includes("Cannot find module './helper'")),
+      `Expected missing-module diagnostic after deleting opened helper.ts, got: ${JSON.stringify(diags)}`,
+    );
+  });
+});