fix: file reloading mechanism and add profile watch ignores

packages/wxt/src/core/__tests__/create-server.test.ts

@@ -0,0 +1,88 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { createFileReloader } from '../create-server';
+import { findEntrypoints, rebuild } from '../utils/building';
+import {
+  fakeBackgroundEntrypoint,
+  fakeBuildOutput,
+  fakeDevServer,
+  fakeOutputChunk,
+  setFakeWxt,
+} from '../utils/testing/fake-objects';
+
+vi.mock('../utils/building', async () => {
+  const actual =
+    await vi.importActual<typeof import('../utils/building')>(
+      '../utils/building',
+    );
+  return {
+    ...actual,
+    findEntrypoints: vi.fn(),
+    rebuild: vi.fn(),
+  };
+});
+
+describe('createFileReloader', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    setFakeWxt({
+      config: {
+        root: '/root',
+        dev: {
+          server: {
+            watchDebounce: 100,
+          },
+        },
+      },
+    });
+    vi.mocked(findEntrypoints).mockResolvedValue([]);
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+    vi.useRealTimers();
+  });
+
+  it('should detect relevant file changes even when noisy file events happen first', async () => {
+    const relevantFile = '/root/src/entrypoints/background.ts';
+    const noisyProfileFile =
+      '/root/private/.dev-profile/Default/Cache/Cache_Data/d573fa6484e43cf9_0';
+    const backgroundEntrypoint = fakeBackgroundEntrypoint({
+      inputPath: relevantFile,
+    });
+    const currentOutput = fakeBuildOutput({
+      steps: [
+        {
+          entrypoints: backgroundEntrypoint,
+          chunks: [fakeOutputChunk({ moduleIds: [relevantFile] })],
+        },
+      ],
+      publicAssets: [],
+    });
+    const server = fakeDevServer({
+      currentOutput,
+      reloadExtension: vi.fn(),
+    });
+
+    vi.mocked(rebuild).mockResolvedValue({
+      output: currentOutput,
+      manifest: currentOutput.manifest,
+      warnings: [],
+    });
+
+    const reloadOnChange = createFileReloader(server);
+
+    const fixedFirst = reloadOnChange('change', noisyProfileFile);
+    await vi.advanceTimersByTimeAsync(50);
+    const fixedSecond = reloadOnChange('change', relevantFile);
+    await vi.advanceTimersByTimeAsync(500);
+    await Promise.all([fixedFirst, fixedSecond]);
+
+    expect(rebuild).toBeCalledTimes(1);
+    expect(rebuild).toBeCalledWith(
+      [],
+      [expect.objectContaining({ inputPath: relevantFile })],
+      expect.anything(),
+    );
+    expect(server.reloadExtension).toBeCalledTimes(1);
+  });
+});

packages/wxt/src/core/builders/vite/index.ts

@@ -25,7 +25,7 @@ import { ViteNodeServer } from 'vite-node/server';
 import { ViteNodeRunner } from 'vite-node/client';
 import { installSourcemapsSupport } from 'vite-node/source-map';
 import { createExtensionEnvironment } from '../../utils/environments';
-import { dirname, extname, join, relative } from 'node:path';
+import { dirname, extname, join, relative, resolve } from 'node:path';
 import fs from 'fs-extra';
 import { normalizePath } from '../../utils';
 
@@ -66,7 +66,11 @@ export async function createViteBuilder(
 
     config.server ??= {};
     config.server.watch = {
-      ignored: [`${wxtConfig.outBaseDir}/**`, `${wxtConfig.wxtDir}/**`],
+      ignored: [
+        `${wxtConfig.outBaseDir}/**`,
+        `${wxtConfig.wxtDir}/**`,
+        ...getRunnerProfileWatchIgnores(wxtConfig),
+      ],
     };
 
     // TODO: Remove once https://github.com/wxt-dev/wxt/pull/1411 is merged
@@ -371,6 +375,59 @@ export async function createViteBuilder(
   };
 }
 
+export function getRunnerProfileWatchIgnores(
+  wxtConfig: ResolvedConfig,
+): string[] {
+  const root = normalizePath(wxtConfig.root);
+  const chromiumArgProfiles = extractPathArgs(
+    wxtConfig.runnerConfig.config?.chromiumArgs,
+    '--user-data-dir',
+  );
+  const firefoxArgProfiles = extractPathArgs(
+    wxtConfig.runnerConfig.config?.firefoxArgs,
+    '-profile',
+  );
+  const profiles = [
+    wxtConfig.runnerConfig.config?.chromiumProfile,
+    wxtConfig.runnerConfig.config?.firefoxProfile,
+    ...chromiumArgProfiles,
+    ...firefoxArgProfiles,
+  ].filter((profile): profile is string => typeof profile === 'string');
+
+  return Array.from(
+    new Set(
+      profiles
+        .map((profile) => normalizePath(resolve(wxtConfig.root, profile)))
+        // Avoid accidentally disabling all file watching.
+        .filter((profilePath) => profilePath !== root)
+        .map((profilePath) => `${profilePath}/**`),
+    ),
+  );
+}
+
+function extractPathArgs(args: string[] | undefined, flag: string): string[] {
+  if (!args?.length) return [];
+
+  const paths: string[] = [];
+  for (let i = 0; i < args.length; i++) {
+    const arg = args[i];
+
+    if (arg.startsWith(`${flag}=`)) {
+      const value = arg.slice(flag.length + 1).trim();
+      if (value) paths.push(value);
+      continue;
+    }
+
+    if (arg === flag) {
+      const nextValue = args[i + 1]?.trim();
+      if (nextValue) paths.push(nextValue);
+      i += 1;
+    }
+  }
+
+  return paths;
+}
+
 function getBuildOutputChunks(
   result: Awaited<ReturnType<typeof vite.build>>,
 ): BuildStepOutput['chunks'] {

packages/wxt/src/core/create-server.ts

@@ -1,4 +1,3 @@
-import { debounce } from 'perfect-debounce';
 import chokidar from 'chokidar';
 import {
   BuildStepOutput,
@@ -15,6 +14,7 @@ import {
 import {
   internalBuild,
   detectDevChanges,
+  getRelevantDevChangedFiles,
   rebuild,
   findEntrypoints,
 } from './utils/building';
@@ -202,24 +202,31 @@ async function createServerInternal(): Promise<WxtDevServer> {
  * Returns a function responsible for reloading different parts of the extension when a file
  * changes.
  */
-function createFileReloader(server: WxtDevServer) {
+export function createFileReloader(server: WxtDevServer) {
   const fileChangedMutex = new Mutex();
   const changeQueue: Array<[string, string]> = [];
+  let processLoop: Promise<void> | undefined;
 
-  const cb = async (event: string, path: string) => {
-    changeQueue.push([event, path]);
-
+  const processQueue = async () => {
     const reloading = fileChangedMutex.runExclusive(async () => {
-      if (server.currentOutput == null) return;
-
       const fileChanges = changeQueue
         .splice(0, changeQueue.length)
         .map(([_, file]) => file);
       if (fileChanges.length === 0) return;
+      if (server.currentOutput == null) return;
+
+      const relevantFileChanges = getRelevantDevChangedFiles(
+        fileChanges,
+        server.currentOutput,
+      );
+      if (relevantFileChanges.length === 0) return;
 
       await wxt.reloadConfig();
 
-      const changes = detectDevChanges(fileChanges, server.currentOutput);
+      const changes = detectDevChanges(
+        relevantFileChanges,
+        server.currentOutput,
+      );
       if (changes.type === 'no-change') return;
 
       if (changes.type === 'full-restart') {
@@ -236,7 +243,7 @@ function createFileReloader(server: WxtDevServer) {
 
       // Log the entrypoints that were effected
       wxt.logger.info(
-        `Changed: ${Array.from(new Set(fileChanges))
+        `Changed: ${relevantFileChanges
           .map((file) => pc.dim(relative(wxt.config.root, file)))
           .join(', ')}`,
       );
@@ -288,10 +295,30 @@ function createFileReloader(server: WxtDevServer) {
     });
   };
 
-  return debounce(cb, wxt.config.dev.server!.watchDebounce, {
-    leading: true,
-    trailing: false,
-  });
+  const waitForDebounceWindow = async () => {
+    await new Promise((resolve) => {
+      setTimeout(resolve, wxt.config.dev.server!.watchDebounce);
+    });
+  };
+
+  const queueWorker = async () => {
+    while (true) {
+      await processQueue();
+
+      await waitForDebounceWindow();
+      if (changeQueue.length === 0) break;
+    }
+  };
+
+  return async (event: string, path: string) => {
+    // Queue every event before debouncing so we never drop changes.
+    changeQueue.push([event, path]);
+
+    processLoop ??= queueWorker().finally(() => {
+      processLoop = undefined;
+    });
+    await processLoop;
+  };
 }
 
 /**

packages/wxt/src/core/utils/building/__tests__/detect-dev-changes.test.ts

@@ -252,6 +252,60 @@ describe('Detect Dev Changes', () => {
       expect(actual).toEqual(expected);
     });
 
+    it('should ignore unrelated changed files when checking html-only reloads', async () => {
+      const changedPath = '/root/page1.html';
+      const unrelatedPath =
+        '/root/private/.dev-profile/Default/Cache/Cache_Data/1004_0';
+      const htmlPage1 = fakePopupEntrypoint({
+        inputPath: changedPath,
+      });
+      const htmlPage2 = fakeOptionsEntrypoint({
+        inputPath: '/root/page2.html',
+      });
+      const htmlPage3 = fakeGenericEntrypoint({
+        type: 'sandbox',
+        inputPath: '/root/page3.html',
+      });
+
+      const step1: BuildStepOutput = {
+        entrypoints: [htmlPage1, htmlPage2],
+        chunks: [
+          fakeOutputAsset({
+            fileName: 'page1.html',
+          }),
+        ],
+      };
+      const step2: BuildStepOutput = {
+        entrypoints: [htmlPage3],
+        chunks: [
+          fakeOutputAsset({
+            fileName: 'page2.html',
+          }),
+        ],
+      };
+
+      const currentOutput: BuildOutput = {
+        manifest: fakeManifest(),
+        publicAssets: [],
+        steps: [step1, step2],
+      };
+      const expected: DevModeChange = {
+        type: 'html-reload',
+        cachedOutput: {
+          ...currentOutput,
+          steps: [step2],
+        },
+        rebuildGroups: [[htmlPage1, htmlPage2]],
+      };
+
+      const actual = detectDevChanges(
+        [unrelatedPath, changedPath],
+        currentOutput,
+      );
+
+      expect(actual).toEqual(expected);
+    });
+
     it('should detect changes to entrypoints/<name>/index.html files', async () => {
       const changedPath = '/root/page1/index.html';
       const htmlPage1 = fakePopupEntrypoint({

packages/wxt/src/core/utils/building/detect-dev-changes.ts

@@ -36,30 +36,35 @@ export function detectDevChanges(
   changedFiles: string[],
   currentOutput: BuildOutput,
 ): DevModeChange {
-  const isConfigChange = some(
+  const relevantChangedFiles = getRelevantDevChangedFiles(
     changedFiles,
+    currentOutput,
+  );
+
+  const isConfigChange = some(
+    relevantChangedFiles,
     (file) => file === wxt.config.userConfigMetadata.configFile,
   );
   if (isConfigChange) return { type: 'full-restart' };
 
-  const isWxtModuleChange = some(changedFiles, (file) =>
+  const isWxtModuleChange = some(relevantChangedFiles, (file) =>
     file.startsWith(wxt.config.modulesDir),
   );
   if (isWxtModuleChange) return { type: 'full-restart' };
 
   const isRunnerChange = some(
-    changedFiles,
+    relevantChangedFiles,
     (file) => file === wxt.config.runnerConfig.configFile,
   );
   if (isRunnerChange) return { type: 'browser-restart' };
 
   const changedSteps = new Set(
-    changedFiles.flatMap((changedFile) =>
+    relevantChangedFiles.flatMap((changedFile) =>
       findEffectedSteps(changedFile, currentOutput),
     ),
   );
   if (changedSteps.size === 0) {
-    const hasPublicChange = some(changedFiles, (file) =>
+    const hasPublicChange = some(relevantChangedFiles, (file) =>
       file.startsWith(wxt.config.publicDir),
     );
     if (hasPublicChange) {
@@ -93,8 +98,8 @@ export function detectDevChanges(
   }
 
   const isOnlyHtmlChanges =
-    changedFiles.length > 0 &&
-    every(changedFiles, (file) => file.endsWith('.html'));
+    relevantChangedFiles.length > 0 &&
+    every(relevantChangedFiles, (file) => file.endsWith('.html'));
   if (isOnlyHtmlChanges) {
     return {
       type: 'html-reload',
@@ -125,6 +130,19 @@ export function detectDevChanges(
   };
 }
 
+export function getRelevantDevChangedFiles(
+  changedFiles: string[],
+  currentOutput: BuildOutput,
+): string[] {
+  return Array.from(new Set(changedFiles)).filter((changedFile) => {
+    if (changedFile === wxt.config.userConfigMetadata.configFile) return true;
+    if (changedFile.startsWith(wxt.config.modulesDir)) return true;
+    if (changedFile === wxt.config.runnerConfig.configFile) return true;
+    if (changedFile.startsWith(wxt.config.publicDir)) return true;
+    return findEffectedSteps(changedFile, currentOutput).length > 0;
+  });
+}
+
 /**
  * For a single change, return all the step of the build output that were effected by it.
  */