Bump version to alpha2

CHANGELOG.md

@@ -1,36 +1,5 @@
 # Changelog
 
-## v0.14.2
-
-[compare changes](https://github.com/wxt-dev/wxt/compare/v0.14.1...v0.14.2)
-
-### 🚀 Enhancements
-
-- Add `filterEntrypoints` option to speed up development ([#344](https://github.com/wxt-dev/wxt/pull/344))
-
-### 🔥 Performance
-
-- Only call `findEntrypoint` once per build ([#342](https://github.com/wxt-dev/wxt/pull/342))
-
-### 🩹 Fixes
-
-- Improve error message and document use of imported variables outside an entrypoint's `main` function ([#346](https://github.com/wxt-dev/wxt/pull/346))
-- Allow `browser.runtime.getURL` to include hashes and query params for HTML paths ([#350](https://github.com/wxt-dev/wxt/pull/350))
-
-### 📖 Documentation
-
-- Fix typos and outdated ui function usage ([#347](https://github.com/wxt-dev/wxt/pull/347))
-
-### 🏡 Chore
-
-- Update templates to `^0.14.0` ([70a4961](https://github.com/wxt-dev/wxt/commit/70a4961))
-- Fix typo in function name ([a329e24](https://github.com/wxt-dev/wxt/commit/a329e24))
-
-### ❤️ Contributors
-
-- Yuns ([@yunsii](http://github.com/yunsii))
-- Armin
-
 ## v0.14.1
 
 [compare changes](https://github.com/wxt-dev/wxt/compare/v0.14.0...v0.14.1)

demo/src/entrypoints/background.ts

@@ -1,5 +1,3 @@
-import messages from 'public/_locales/en/messages.json';
-
 export default defineBackground(() => {
   console.log(browser.runtime.id);
   logId();
@@ -8,24 +6,32 @@ export default defineBackground(() => {
     chrome: __IS_CHROME__,
     firefox: __IS_FIREFOX__,
     manifestVersion: __MANIFEST_VERSION__,
-    messages,
   });
 
   // @ts-expect-error: should only accept entrypoints or public assets
   browser.runtime.getURL('/');
   browser.runtime.getURL('/background.js');
-  browser.runtime.getURL('/icon/128.png');
-  browser.runtime.getURL('/example.html#hash');
-  browser.runtime.getURL('/example.html?query=param');
-  // @ts-expect-error: should only allow hashes/query params on HTML files
-  browser.runtime.getURL('/icon-128.png?query=param');
+  browser.runtime.getURL('/icon-128.png');
 
-  // @ts-expect-error: should only accept known message names
-  browser.i18n.getMessage('test');
-  browser.i18n.getMessage('prompt_for_name');
-  browser.i18n.getMessage('hello', 'Aaron');
-  browser.i18n.getMessage('bye', ['Aaron']);
-  browser.i18n.getMessage('@@extension_id');
+  console.log([
+    // @ts-expect-error: browser.i18n should only accept known message names
+    browser.i18n.getMessage('test'),
+    browser.i18n.getMessage('promptForName'),
+    browser.i18n.getMessage('hello', ['Aaron']),
+    browser.i18n.getMessage('bye', ['Aaron']),
+    browser.i18n.getMessage('@@extension_id'),
+    browser.i18n.getMessage('nItems'),
+  ]);
+
+  console.log([
+    // @ts-expect-error: i18n should only accept known message names
+    i18n.t('test'),
+    i18n.t('promptForName'),
+    i18n.t('hello', ['Aaron']),
+    i18n.t('bye', ['Aaron']),
+    i18n.t('@@extension_id'),
+    i18n.tp('nItems', 0, ['0']),
+  ]);
 
   console.log('WXT MODE:', {
     MODE: import.meta.env.MODE,

demo/src/locales/en.yml

@@ -0,0 +1,21 @@
+promptForName: What's your name?
+hello:
+  message: Hello, $USER$
+  description: Greet the user
+  placeholders:
+    user:
+      content: $1
+      example: Paul
+bye:
+  message: Goodbye, $USER$. Come back to $OUR_SITE$ soon!
+  description: Say goodbye to the user
+  placeholders:
+    our_site:
+      content: Example.com
+    user:
+      content: $1
+      example: Paul
+nItems:
+  0: 0 items
+  1: 1 item
+  n: $1 items

demo/src/public/_locales/en/messages.json

@@ -1,29 +0,0 @@
-{
-  "prompt_for_name": {
-    "message": "What's your name?",
-    "description": "Ask for the user's name"
-  },
-  "hello": {
-    "message": "Hello, $USER$",
-    "description": "Greet the user",
-    "placeholders": {
-      "user": {
-        "content": "$1",
-        "example": "Cira"
-      }
-    }
-  },
-  "bye": {
-    "message": "Goodbye, $USER$. Come back to $OUR_SITE$ soon!",
-    "description": "Say goodbye to the user",
-    "placeholders": {
-      "our_site": {
-        "content": "Example.com"
-      },
-      "user": {
-        "content": "$1",
-        "example": "Cira"
-      }
-    }
-  }
-}

docs/.vitepress/config.ts

@@ -89,6 +89,7 @@ export default defineConfig({
             { text: 'Storage', link: '/guide/storage.md' },
             { text: 'Assets', link: '/guide/assets.md' },
             { text: 'Content Script UI', link: '/guide/content-script-ui.md' },
+            { text: 'Localization', link: '/guide/localization.md' },
             { text: 'Multiple Browsers', link: '/guide/multiple-browsers.md' },
             { text: 'Auto-imports', link: '/guide/auto-imports.md' },
             { text: 'Vite', link: '/guide/vite.md' },

docs/guide/content-script-ui.md

@@ -95,7 +95,7 @@ export default defineContentScript({
 });
 ```
 
-```ts [Svelte]
+```ts [Svelete]
 // entrypoints/example-ui.content/index.ts
 import App from './App.svelte';
 
@@ -243,8 +243,7 @@ export default defineContentScript({
 
   main(ctx) {
     // 3. Define your UI
-    const ui = createShadowRootUi(ctx, {
-      name: 'example-ui',
+    const ui = createIntegratedUi(ctx, {
       position: 'inline',
       anchor: '#anchor',
       onMount: (container) => {
@@ -265,7 +264,7 @@ export default defineContentScript({
 });
 ```
 
-```ts [Svelte]
+```ts [Svelete]
 // 1. Import the style
 import './style.css';
 import App from './App.svelte';
@@ -276,8 +275,7 @@ export default defineContentScript({
 
   main(ctx) {
     // 3. Define your UI
-    const ui = createShadowRootUi(ctx, {
-      name: 'example-ui',
+    const ui = createIntegratedUi(ctx, {
       position: 'inline',
       anchor: '#anchor',
       onMount: (container) => {
@@ -310,8 +308,7 @@ export default defineContentScript({
 
   main(ctx) {
     // 3. Define your UI
-    const ui = createShadowRootUi(ctx, {
-      name: 'example-ui',
+    const ui = createIntegratedUi(ctx, {
       position: 'inline',
       anchor: '#anchor',
       onMount: (container) => {

docs/guide/entrypoints.md

@@ -86,56 +86,3 @@ export default defineContentScript({
 :::info
 For a full list of entrypoints and each of their options, see the [`/entrypoints` folder](/entrypoints/background) documentation.
 :::
-
-### Side Effects
-
-You cannot use imported variables outside the `main` function is JS entrypoints. This includes options, as shown below:
-
-```ts
-// entrypoints/content.ts
-import { GOOGLE_MATCHES } from '~/utils/match-patterns';
-
-export default defineContentScript({
-  matches: GOOGLE_MATCHES,
-  main() {
-    // ...
-  },
-});
-```
-
-```
-$ wxt build
-wxt build
-
-WXT 0.14.1
-ℹ Building chrome-mv3 for production with Vite 5.0.5
-✖ Command failed after 360 ms
-
-[8:55:54 AM]  ERROR  entrypoints/content.ts: Cannot use imported variable "GOOGLE_MATCHES" before main function. See https://wxt.dev/guide/entrypoints.html#side-effects
-```
-
-This throws an error because WXT needs to import each entrypoint during the build process to extract its definition (containing the `match`, `run_at`, `include`/`exclude`, etc.) to render the `manifest.json` correctly. Before loading an entrypoint, a transformation is applied to remove all imports. This prevents imported modules (local or NPM) with side-effects from running during the build process, potentially throwing an error.
-
-:::details Why?
-
-When importing your entrypoint to get its definition, the file is imported in a **_node environement_**, and doesn't have access to the `window`, `chrome`, or `browser` globals a web extension ususally has access to. If WXT doesn't remove all the imports from the file, the imported modules could try and access one of these variables, throwing an error.
-
-:::
-
-:::warning
-See [`wxt-dev/wxt#336`](https://github.com/wxt-dev/wxt/issues/336) to track the status of this bug.
-:::
-
-Usually, this error occurs when you try to extract options into a shared file or try to run code outside the `main` function. To fix the example from above, use litteral values when defining an entrypoint instead of importing them:
-
-```ts
-import { GOOGLE_MATCHES } from '~/utils/match-patterns'; // [!code --]
-
-export default defineContentScript({
-  matches: GOOGLE_MATCHES, // [!code --]
-  matches: ['*//*.google.com/*'], // [!code ++]
-  main() {
-    // ...
-  },
-});
-```

docs/guide/localization.md

@@ -0,0 +1,159 @@
+---
+outline: deep
+---
+
+# Localization
+
+WXT includes a util, [`i18n`](/api/wxt/i18n/), that provides a type-safe feature-rich alternative to `browser.i18n.getMessage`.
+
+It is available automatically when you create a messages file under the `locales/` directory, and add a `default_locale` to the manifest:
+
+```
+<srcDir>
+└─ locales/
+   ├─ en.json
+   ├─ es.json5
+   ├─ fr.yml
+   ├─ de.yaml
+   └─ ...
+```
+
+> You can use JSON, JSON5, or YAML formats.
+
+```ts
+// wxt.config.ts
+export default defineConfig({
+  manifest: {
+    default_locale: 'en',
+  },
+});
+```
+
+## Message File Format
+
+```yml
+# Use plain strings
+simpleMessage: Hello world!
+
+# Nest strings in objects
+popup:
+  overview:
+    title: Nested text
+
+# Plural form support
+items:
+  1: 1 item
+  n: $1 items
+# Optionally include a custom string for 0
+cartSize:
+  0: Empty
+  1: 1 item
+  n: $1 items
+
+# Or stick with the standard web extension format (with a message, description, and placeholders)
+manifestMessage:
+  message: $THIS$ is translated
+  description: This is not-translated, helps translators
+  placeholder:
+    this:
+      content: This
+```
+
+:::tip
+`locales/<code>.json` is 100% compatible with the standard web extension localization format (`_locales/<code>/messages.json`). If you have existing messages files, just move them into the `locales/` directory.
+:::
+
+## Usage
+
+`i18n` is auto-imported, but can be manually imported from `wxt/i18n`.
+
+```ts
+import { i18n } from 'wxt/i18n';
+```
+
+### Basic Usage
+
+You can access messages by their name:
+
+```yml
+helloWorld: Hello world!
+```
+
+```ts
+i18n.t('helloWorld'); // "Hello world!"
+```
+
+Nested messages are combined into one string using an `_`.
+
+```yml
+popup:
+  overview:
+    title: Hello world!
+```
+
+```ts
+i18n.t('popup_overview_title'); // "Hello world!"
+```
+
+If a message is in the standard web extension format, don't include a `_message`, even if it's nested.
+
+```yml
+helloWorld:
+  message: Hello world!
+  description: Some description
+popup:
+  overview:
+    title:
+      message: Nested Title
+```
+
+```ts
+i18n.t('helloWorld'); // "Hello world!"
+i18n.t('popup_overview_title'); // "Nested Title"
+```
+
+### Substitutions
+
+To insert a custom string into a translation, pass an array of values as the second parameter of the `i18n.t` function:
+
+```yml
+hello: Hello, $1, my name is $2.
+```
+
+```ts
+i18n.t('hello', ['Aaron', 'Mark']); // "Hello Aaron, my name is Mark."
+```
+
+### Plural Form
+
+When getting the translation for text with a plural form, use the `i18n.tp` function.
+
+```yml
+friends:
+  0: I have no friends.
+  1: I have a friend.
+  n: I have many friends.
+```
+
+```ts
+i18n.tp('friends', 0); // "I have no friends."
+i18n.tp('friends', 1); // "I have one friend."
+i18n.tp('friends', 2); // "I have many friends."
+```
+
+The first number is the `count`. It is what decides which form will be used.
+
+Substitutions are not required. But usually, a plural form will look something like this:
+
+```yml
+items:
+  1: 1 item
+  n: $1 items
+```
+
+```ts
+i18n.tp('items', 0, ['0']); // "0 items"
+i18n.tp('items', 1, ['1']); // "1 item"
+i18n.tp('items', 2, ['2']); // "2 items"
+i18n.tp('items', 3, ['3']); // "3 items"
+```

docs/typedoc.json

@@ -5,7 +5,8 @@
     "../src/browser.ts",
     "../src/sandbox",
     "../src/storage.ts",
-    "../src/testing"
+    "../src/testing",
+    "../src/i18n"
   ],
   "plugin": ["typedoc-plugin-markdown", "typedoc-vitepress-theme"],
   "out": "./api",

e2e/tests/auto-imports.test.ts

@@ -28,6 +28,7 @@ describe('Auto Imports', () => {
             const defineContentScript: typeof import('wxt/sandbox')['defineContentScript']
             const defineUnlistedScript: typeof import('wxt/sandbox')['defineUnlistedScript']
             const fakeBrowser: typeof import('wxt/testing')['fakeBrowser']
+            const i18n: typeof import('wxt/i18n')['i18n']
             const storage: typeof import('wxt/storage')['storage']
           }
           "

e2e/tests/typescript-project.test.ts

@@ -49,10 +49,8 @@ describe('TypeScript Project', () => {
           | "/options.html"
           | "/popup.html"
           | "/sandbox.html"
-        type HtmlPublicPath = Extract<PublicPath, \`\${string}.html\`>
         export interface WxtRuntime extends Runtime.Static {
           getURL(path: PublicPath): string;
-          getURL(path: \`\${HtmlPublicPath}\${string}\`): string;
         }
       }
       "
@@ -63,7 +61,7 @@ describe('TypeScript Project', () => {
     const project = new TestProject();
     project.addFile('entrypoints/unlisted.html');
     project.addFile(
-      'public/_locales/en/messages.json',
+      'locales/en.json',
       JSON.stringify({
         prompt_for_name: {
           message: "What's your name?",
@@ -121,6 +119,36 @@ describe('TypeScript Project', () => {
         }
 
         export interface WxtI18n extends I18n.Static {
+          /**
+           * Ask for the user's name
+           *
+           * "What's your name?"
+           */
+          getMessage(
+            messageName: "prompt_for_name",
+            substitutions?: string | string[],
+            options?: GetMessageOptions,
+          ): string;
+          /**
+           * Greet the user
+           *
+           * "Hello, $USER$"
+           */
+          getMessage(
+            messageName: "hello",
+            substitutions?: string | string[],
+            options?: GetMessageOptions,
+          ): string;
+          /**
+           * Say goodbye to the user
+           *
+           * "Goodbye, $USER$. Come back to $OUR_SITE$ soon!"
+           */
+          getMessage(
+            messageName: "bye",
+            substitutions?: string | string[],
+            options?: GetMessageOptions,
+          ): string;
           /**
            * The extension or app ID; you might use this string to construct URLs for resources inside the extension. Even unlocalized extensions can use this message.
       Note: You can't use this message in a manifest file.
@@ -133,7 +161,7 @@ describe('TypeScript Project', () => {
             options?: GetMessageOptions,
           ): string;
           /**
-           * 
+           * No message description.
            *
            * "<browser.i18n.getUiLocale()>"
            */
@@ -182,36 +210,25 @@ describe('TypeScript Project', () => {
             substitutions?: string | string[],
             options?: GetMessageOptions,
           ): string;
-          /**
-           * Ask for the user's name
-           *
-           * "What's your name?"
-           */
-          getMessage(
-            messageName: "prompt_for_name",
-            substitutions?: string | string[],
-            options?: GetMessageOptions,
-          ): string;
-          /**
-           * Greet the user
-           *
-           * "Hello, $USER$"
-           */
-          getMessage(
-            messageName: "hello",
-            substitutions?: string | string[],
-            options?: GetMessageOptions,
-          ): string;
-          /**
-           * Say goodbye to the user
-           *
-           * "Goodbye, $USER$. Come back to $OUR_SITE$ soon!"
-           */
-          getMessage(
-            messageName: "bye",
-            substitutions?: string | string[],
-            options?: GetMessageOptions,
-          ): string;
+        }
+      }
+
+      declare module "wxt/i18n" {
+        export interface WxtMessageSchema {
+          t: {
+            "prompt_for_name": any;
+            "hello": any;
+            "bye": any;
+            "@@extension_id": any;
+            "@@ui_locale": any;
+            "@@bidi_dir": any;
+            "@@bidi_reversed_dir": any;
+            "@@bidi_start_edge": any;
+            "@@bidi_end_edge": any;
+          };
+          tp: {
+
+          };
         }
       }
       "

package.json

@@ -1,7 +1,7 @@
 {
   "name": "wxt",
   "type": "module",
-  "version": "0.14.2",
+  "version": "0.14.2-alpha2",
   "description": "Next gen framework for developing web extensions",
   "engines": {
     "node": ">=18",
@@ -77,6 +77,16 @@
         "default": "./dist/storage.cjs"
       }
     },
+    "./i18n": {
+      "import": {
+        "types": "./dist/i18n.d.ts",
+        "default": "./dist/i18n.js"
+      },
+      "require": {
+        "types": "./dist/i18n.d.cts",
+        "default": "./dist/i18n.cjs"
+      }
+    },
     "./vite-builder-env": {
       "types": "./dist/vite-builder-env.d.ts"
     }
@@ -135,6 +145,7 @@
     "vite": "^5.0.0",
     "web-ext-run": "^0.1.0",
     "webextension-polyfill": "^0.10.0",
+    "yaml": "^2.3.4",
     "zip-dir": "^2.0.0"
   },
   "devDependencies": {

pnpm-lock.yaml

@@ -104,6 +104,9 @@ importers:
       webextension-polyfill:
         specifier: ^0.10.0
         version: 0.10.0
+      yaml:
+        specifier: ^2.3.4
+        version: 2.3.4
       zip-dir:
         specifier: ^2.0.0
         version: 2.0.0
@@ -5385,7 +5388,6 @@ packages:
   /yaml@2.3.4:
     resolution: {integrity: sha512-8aAvwVUSHpfEqTQ4w/KMlf3HcRdt50E5ODIQJBw1fQ5RL34xabzxtUlzTXVqc4rkZsPbvrXKWnABCD7kWSmocA==}
     engines: {node: '>= 14'}
-    dev: true
 
   /yargs-parser@21.1.1:
     resolution: {integrity: sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==}

scripts/build.ts

@@ -58,6 +58,7 @@ const config: tsup.Options[] = [
       index: 'src/index.ts',
       testing: 'src/testing/index.ts',
       storage: 'src/storage.ts',
+      i18n: 'src/i18n/index.ts',
     },
     format: ['cjs', 'esm'],
     clean: true,

src/cli.ts

@@ -20,13 +20,6 @@ cli
   .option('-c, --config <file>', 'use specified config file')
   .option('-m, --mode <mode>', 'set env mode')
   .option('-b, --browser <browser>', 'specify a browser')
-  .option(
-    '-e, --filter-entrypoint <entrypoint>',
-    'only build specific entrypoints',
-    {
-      type: [],
-    },
-  )
   .option('--mv3', 'target manifest v3')
   .option('--mv2', 'target manifest v2')
   .action(
@@ -38,7 +31,6 @@ cli
         manifestVersion: flags.mv3 ? 3 : flags.mv2 ? 2 : undefined,
         configFile: flags.config,
         debug: flags.debug,
-        filterEntrypoints: getArrayFromFlags(flags, 'filterEntrypoint'),
       });
       await server.start();
       return { isOngoing: true };
@@ -51,13 +43,6 @@ cli
   .option('-c, --config <file>', 'use specified config file')
   .option('-m, --mode <mode>', 'set env mode')
   .option('-b, --browser <browser>', 'specify a browser')
-  .option(
-    '-e, --filter-entrypoint <entrypoint>',
-    'only build specific entrypoints',
-    {
-      type: [],
-    },
-  )
   .option('--mv3', 'target manifest v3')
   .option('--mv2', 'target manifest v2')
   .option('--analyze', 'visualize extension bundle')
@@ -73,7 +58,6 @@ cli
         analysis: {
           enabled: flags.analyze,
         },
-        filterEntrypoints: getArrayFromFlags(flags, 'filterEntrypoint'),
       });
     }),
   );
@@ -181,12 +165,3 @@ function wrapAction(
     }
   };
 }
-
-/**
- * Array flags, when not passed, are either `undefined` or `[undefined]`. This function filters out
- * the
- */
-function getArrayFromFlags<T>(flags: any, name: string): T[] | undefined {
-  const array = [flags[name]].flat() as Array<T | undefined>;
-  return array.filter((item) => item != null) as T[];
-}

src/core/utils/__tests__/entrypoints.test.ts

@@ -47,7 +47,6 @@ describe('Entrypoint Utils', () => {
         name,
         outputDir,
         options: {},
-        skipped: false,
       };
 
       const actual = getEntrypointOutputFile(entrypoint, ext);

src/core/utils/__tests__/manifest.test.ts

@@ -339,7 +339,6 @@ describe('Manifest Utils', () => {
           options: {
             matches: ['*://google.com/*'],
           },
-          skipped: false,
         };
         const cs1Styles: OutputAsset = {
           type: 'asset',
@@ -354,7 +353,6 @@ describe('Manifest Utils', () => {
             matches: ['*://google.com/*'],
             runAt: 'document_end',
           },
-          skipped: false,
         };
         const cs2Styles: OutputAsset = {
           type: 'asset',
@@ -369,7 +367,6 @@ describe('Manifest Utils', () => {
             matches: ['*://google.com/*'],
             runAt: 'document_end',
           },
-          skipped: false,
         };
         const cs3Styles: OutputAsset = {
           type: 'asset',
@@ -384,7 +381,6 @@ describe('Manifest Utils', () => {
             matches: ['*://duckduckgo.com/*'],
             runAt: 'document_end',
           },
-          skipped: false,
         };
         const cs4Styles: OutputAsset = {
           type: 'asset',
@@ -399,7 +395,6 @@ describe('Manifest Utils', () => {
             matches: ['*://google.com/*'],
             world: 'MAIN',
           },
-          skipped: false,
         };
         const cs5Styles: OutputAsset = {
           type: 'asset',
@@ -459,7 +454,6 @@ describe('Manifest Utils', () => {
           options: {
             matches: ['*://google.com/*'],
           },
-          skipped: false,
         };
         const generatedContentScript = {
           matches: ['*://google.com/*'],
@@ -499,7 +493,6 @@ describe('Manifest Utils', () => {
                 matches: ['*://google.com/*'],
                 cssInjectionMode,
               },
-              skipped: false,
             };
             const styles: OutputAsset = {
               type: 'asset',
@@ -544,7 +537,6 @@ describe('Manifest Utils', () => {
                 matches: ['*://google.com/*'],
                 cssInjectionMode,
               },
-              skipped: false,
             };
             const styles: OutputAsset = {
               type: 'asset',
@@ -586,7 +578,6 @@ describe('Manifest Utils', () => {
               matches: ['*://google.com/*'],
               cssInjectionMode: 'ui',
             },
-            skipped: false,
           };
           const styles: OutputAsset = {
             type: 'asset',
@@ -628,7 +619,6 @@ describe('Manifest Utils', () => {
               matches: ['*://google.com/*'],
               cssInjectionMode: 'ui',
             },
-            skipped: false,
           };
           const styles: OutputAsset = {
             type: 'asset',
@@ -667,7 +657,6 @@ describe('Manifest Utils', () => {
               matches: ['*://play.google.com/books/*'],
               cssInjectionMode: 'ui',
             },
-            skipped: false,
           };
           const styles: OutputAsset = {
             type: 'asset',
@@ -712,7 +701,6 @@ describe('Manifest Utils', () => {
             matches: ['*://google.com/*'],
             cssInjectionMode: 'ui',
           },
-          skipped: false,
         };
         const styles: OutputAsset = {
           type: 'asset',
@@ -756,7 +744,6 @@ describe('Manifest Utils', () => {
             matches: ['*://google.com/*'],
             cssInjectionMode: 'ui',
           },
-          skipped: false,
         };
         const styles: OutputAsset = {
           type: 'asset',

src/core/utils/__tests__/test-entrypoints/imported-option.ts

@@ -1,7 +0,0 @@
-import { defineContentScript } from '~/sandbox';
-import { faker } from '@faker-js/faker';
-
-export default defineContentScript({
-  matches: [faker.string.nanoid()],
-  main() {},
-});

src/core/utils/building/__tests__/find-entrypoints.test.ts

@@ -53,7 +53,6 @@ describe('findEntrypoints', () => {
           defaultIcon: { '16': '/icon/16.png' },
           defaultTitle: 'Default Title',
         },
-        skipped: false,
       },
     ],
     [
@@ -73,7 +72,6 @@ describe('findEntrypoints', () => {
         options: {
           defaultTitle: 'Title',
         },
-        skipped: false,
       },
     ],
   ])(
@@ -105,7 +103,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'options.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -126,7 +123,6 @@ describe('findEntrypoints', () => {
         options: {
           openInTab: true,
         },
-        skipped: false,
       },
     ],
   ])(
@@ -150,7 +146,6 @@ describe('findEntrypoints', () => {
         name: 'content',
         inputPath: resolve(config.entrypointsDir, 'content.ts'),
         outputDir: resolve(config.outDir, 'content-scripts'),
-        skipped: false,
       },
     ],
     [
@@ -160,7 +155,6 @@ describe('findEntrypoints', () => {
         name: 'overlay',
         inputPath: resolve(config.entrypointsDir, 'overlay.content.ts'),
         outputDir: resolve(config.outDir, 'content-scripts'),
-        skipped: false,
       },
     ],
     [
@@ -170,7 +164,6 @@ describe('findEntrypoints', () => {
         name: 'content',
         inputPath: resolve(config.entrypointsDir, 'content/index.ts'),
         outputDir: resolve(config.outDir, 'content-scripts'),
-        skipped: false,
       },
     ],
     [
@@ -180,7 +173,6 @@ describe('findEntrypoints', () => {
         name: 'overlay',
         inputPath: resolve(config.entrypointsDir, 'overlay.content/index.ts'),
         outputDir: resolve(config.outDir, 'content-scripts'),
-        skipped: false,
       },
     ],
     [
@@ -190,7 +182,6 @@ describe('findEntrypoints', () => {
         name: 'overlay',
         inputPath: resolve(config.entrypointsDir, 'overlay.content.tsx'),
         outputDir: resolve(config.outDir, 'content-scripts'),
-        skipped: false,
       },
     ],
   ])(
@@ -221,7 +212,6 @@ describe('findEntrypoints', () => {
         name: 'background',
         inputPath: resolve(config.entrypointsDir, 'background.ts'),
         outputDir: config.outDir,
-        skipped: false,
       },
     ],
     [
@@ -231,7 +221,6 @@ describe('findEntrypoints', () => {
         name: 'background',
         inputPath: resolve(config.entrypointsDir, 'background/index.ts'),
         outputDir: config.outDir,
-        skipped: false,
       },
     ],
   ])(
@@ -269,7 +258,6 @@ describe('findEntrypoints', () => {
       name: 'background',
       options: {},
       outputDir: config.outDir,
-      skipped: false,
     });
   });
 
@@ -290,7 +278,6 @@ describe('findEntrypoints', () => {
         name: 'injected',
         inputPath: resolve(config.entrypointsDir, path),
         outputDir: config.outDir,
-        skipped: false,
       };
       const options: GenericEntrypoint['options'] = {};
       globMock.mockResolvedValueOnce([path]);
@@ -317,7 +304,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'sandbox.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -328,7 +314,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'sandbox/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -339,7 +324,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'named.sandbox.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -350,7 +334,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'named.sandbox/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -363,7 +346,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'bookmarks.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -374,7 +356,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'bookmarks/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -387,7 +368,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'history.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -398,7 +378,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'history/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -411,7 +390,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'newtab.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -422,7 +400,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'newtab/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -435,7 +412,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'sidepanel.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -446,7 +422,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'sidepanel/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -457,7 +432,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'named.sidepanel.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -468,7 +442,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'named.sidepanel/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -481,7 +454,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'devtools.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -492,7 +464,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'devtools/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -505,7 +476,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'onboarding.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -516,7 +486,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'onboarding/index.html'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -529,7 +498,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'iframe.scss'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -540,7 +508,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'iframe.css'),
         outputDir: config.outDir,
         options: {},
-        skipped: false,
       },
     ],
 
@@ -553,7 +520,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'content.css'),
         outputDir: resolve(config.outDir, 'content-scripts'),
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -564,7 +530,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'overlay.content.css'),
         outputDir: resolve(config.outDir, 'content-scripts'),
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -575,7 +540,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'content/index.css'),
         outputDir: resolve(config.outDir, 'content-scripts'),
         options: {},
-        skipped: false,
       },
     ],
     [
@@ -586,7 +550,6 @@ describe('findEntrypoints', () => {
         inputPath: resolve(config.entrypointsDir, 'overlay.content/index.css'),
         outputDir: resolve(config.outDir, 'content-scripts'),
         options: {},
-        skipped: false,
       },
     ],
   ])('should find entrypoint for %s', async (path, expected) => {
@@ -774,29 +737,4 @@ describe('findEntrypoints', () => {
       expect(entrypoints).toEqual([]);
     });
   });
-
-  describe('filterEntrypoints option', () => {
-    it('should control entrypoints accessible', async () => {
-      globMock.mockResolvedValue([
-        'options/index.html',
-        'popup/index.html',
-        'ui.content/index.ts',
-        'injected.content/index.ts',
-      ]);
-      importEntrypointFileMock.mockResolvedValue({});
-      const filterEntrypoints = ['popup', 'ui'];
-      const config = fakeInternalConfig({
-        root: '/',
-        entrypointsDir: resolve('/src/entrypoints'),
-        outDir: resolve('.output'),
-        command: 'build',
-        filterEntrypoints: new Set(filterEntrypoints),
-      });
-
-      const entrypoints = await findEntrypoints(config);
-      const names = entrypoints.map((item) => item.name);
-      expect(names).toHaveLength(2);
-      expect(names).toEqual(filterEntrypoints);
-    });
-  });
 });

src/core/utils/building/__tests__/group-entrypoints.test.ts

@@ -8,7 +8,6 @@ const background: Entrypoint = {
   inputPath: '/background.ts',
   outputDir: '/.output/background',
   options: {},
-  skipped: false,
 };
 const contentScript: Entrypoint = {
   type: 'content-script',
@@ -18,7 +17,6 @@ const contentScript: Entrypoint = {
   options: {
     matches: ['<all_urls>'],
   },
-  skipped: false,
 };
 const unlistedScript: Entrypoint = {
   type: 'unlisted-script',
@@ -26,7 +24,6 @@ const unlistedScript: Entrypoint = {
   inputPath: '/injected.ts',
   outputDir: '/.output/injected',
   options: {},
-  skipped: false,
 };
 const popup: Entrypoint = {
   type: 'popup',
@@ -34,7 +31,6 @@ const popup: Entrypoint = {
   inputPath: '/popup.html',
   outputDir: '/.output/popup',
   options: {},
-  skipped: false,
 };
 const unlistedPage: Entrypoint = {
   type: 'unlisted-page',
@@ -42,7 +38,6 @@ const unlistedPage: Entrypoint = {
   inputPath: '/onboarding.html',
   outputDir: '/.output/onboarding',
   options: {},
-  skipped: false,
 };
 const options: Entrypoint = {
   type: 'options',
@@ -50,7 +45,6 @@ const options: Entrypoint = {
   inputPath: '/options.html',
   outputDir: '/.output/options',
   options: {},
-  skipped: false,
 };
 const sandbox1: Entrypoint = {
   type: 'sandbox',
@@ -58,7 +52,6 @@ const sandbox1: Entrypoint = {
   inputPath: '/sandbox1.html',
   outputDir: '/.output/sandbox1',
   options: {},
-  skipped: false,
 };
 const sandbox2: Entrypoint = {
   type: 'sandbox',
@@ -66,7 +59,6 @@ const sandbox2: Entrypoint = {
   inputPath: '/sandbox2.html',
   outputDir: '/.output/sandbox2',
   options: {},
-  skipped: false,
 };
 const unlistedStyle: Entrypoint = {
   type: 'unlisted-style',
@@ -74,7 +66,6 @@ const unlistedStyle: Entrypoint = {
   inputPath: '/injected.scss',
   outputDir: '/.output',
   options: {},
-  skipped: false,
 };
 const contentScriptStyle: Entrypoint = {
   type: 'content-script-style',
@@ -82,7 +73,6 @@ const contentScriptStyle: Entrypoint = {
   inputPath: '/overlay.content.scss',
   outputDir: '/.output/content-scripts',
   options: {},
-  skipped: false,
 };
 
 describe('groupEntrypoints', () => {

src/core/utils/building/__tests__/import-entrypoint.test.ts

@@ -2,7 +2,6 @@ import { describe, expect, it } from 'vitest';
 import { importEntrypointFile } from '~/core/utils/building';
 import { fakeInternalConfig } from '~/core/utils/testing/fake-objects';
 import { resolve } from 'node:path';
-import { unnormalizePath } from '../../paths';
 
 const entrypointPath = (filename: string) =>
   resolve('src/core/utils/__tests__/test-entrypoints', filename);
@@ -39,15 +38,4 @@ describe('importEntrypointFile', () => {
 
     expect(actual).toBeUndefined();
   });
-
-  it('should throw a custom error message when an imported variable is used before main', async () => {
-    const filePath = unnormalizePath(
-      '../src/core/utils/__tests__/test-entrypoints/imported-option.ts',
-    );
-    await expect(() =>
-      importEntrypointFile(entrypointPath('imported-option.ts'), config),
-    ).rejects.toThrowErrorMatchingInlineSnapshot(
-      `[Error: ${filePath}: Cannot use imported variable "faker" outside the main function. See https://wxt.dev/guide/entrypoints.html#side-effects]`,
-    );
-  });
 });

src/core/utils/building/build-entrypoints.ts

@@ -6,9 +6,11 @@ import {
 } from '~/types';
 import { getPublicFiles } from '~/core/utils/fs';
 import fs from 'fs-extra';
-import { dirname, resolve } from 'path';
+import { dirname, resolve, extname } from 'node:path';
 import type { Ora } from 'ora';
 import pc from 'picocolors';
+import { unnormalizePath } from '~/core/utils/paths';
+import { convertMessagesToManifest, readMessagesFile } from '~/i18n/node';
 
 export async function buildEntrypoints(
   groups: EntrypointGroup[],
@@ -25,7 +27,13 @@ export async function buildEntrypoints(
     spinner.text = pc.dim(`[${i + 1}/${groups.length}]`) + ` ${groupNames}`;
     steps.push(await config.builder.build(group));
   }
-  const publicAssets = await copyPublicDirectory(config);
+
+  const publicAssets = (
+    await Promise.all([
+      copyPublicDirectory(config),
+      copyLocalesDirectory(config),
+    ])
+  ).flat();
 
   return { publicAssets, steps };
 }
@@ -51,3 +59,31 @@ async function copyPublicDirectory(
 
   return publicAssets;
 }
+
+async function copyLocalesDirectory(
+  config: InternalConfig,
+): Promise<BuildOutput['publicAssets']> {
+  const localesExist = await fs.exists(config.localesDir);
+  if (!localesExist || config.manifest.default_locale == null) return [];
+
+  const files = await fs.readdir(config.localesDir);
+
+  return await Promise.all(
+    files.map(async (file) => {
+      const locale = file.replace(extname(file), '');
+      const fileName = unnormalizePath(`_locales/${locale}/messages.json`);
+      const srcPath = resolve(config.localesDir, file);
+      const outPath = resolve(config.outDir, fileName);
+
+      const messages = await readMessagesFile(srcPath);
+      const json = convertMessagesToManifest(messages);
+
+      await fs.ensureDir(dirname(outPath));
+      await fs.writeJson(outPath, json);
+      return {
+        fileName,
+        type: 'asset',
+      };
+    }),
+  );
+}

src/core/utils/building/find-entrypoints.ts

@@ -24,7 +24,6 @@ import {
 } from '~/core/utils/entrypoints';
 import { VIRTUAL_NOOP_BACKGROUND_MODULE_ID } from '~/core/utils/constants';
 import { CSS_EXTENSIONS_PATTERN } from '~/core/utils/paths';
-import pc from 'picocolors';
 
 /**
  * Return entrypoints and their configuration by looking through the project's files.
@@ -49,14 +48,7 @@ export async function findEntrypoints(
     );
     if (matchingGlob) {
       const type = PATH_GLOB_TO_TYPE_MAP[matchingGlob];
-      results.push({
-        name,
-        inputPath,
-        type,
-        skipped:
-          config.filterEntrypoints != null &&
-          !config.filterEntrypoints.has(name),
-      });
+      results.push({ name, inputPath, type });
     }
     return results;
   }, []);
@@ -114,22 +106,11 @@ export async function findEntrypoints(
         inputPath: VIRTUAL_NOOP_BACKGROUND_MODULE_ID,
         name: 'background',
         type: 'background',
-        skipped: false,
       }),
     );
   }
 
   config.logger.debug('All entrypoints:', entrypoints);
-  const skippedEntrypointNames = entrypointInfos
-    .filter((item) => item.skipped)
-    .map((item) => item.name);
-  if (skippedEntrypointNames.length) {
-    config.logger.warn(
-      `Filter excluded the following entrypoints:\n${skippedEntrypointNames
-        .map((item) => `${pc.dim('-')} ${pc.cyan(item)}`)
-        .join('\n')}`,
-    );
-  }
   const targetEntrypoints = entrypoints.filter((entry) => {
     const { include, exclude } = entry.options;
     if (include?.length && exclude?.length) {
@@ -144,9 +125,6 @@ export async function findEntrypoints(
     if (include?.length && !exclude?.length) {
       return include.includes(config.browser);
     }
-    if (skippedEntrypointNames.includes(entry.name)) {
-      return false;
-    }
 
     return true;
   });
@@ -158,10 +136,6 @@ interface EntrypointInfo {
   name: string;
   inputPath: string;
   type: Entrypoint['type'];
-  /**
-   * @default false
-   */
-  skipped: boolean;
 }
 
 function preventDuplicateEntrypointNames(
@@ -228,7 +202,7 @@ function getHtmlBaseOptions(document: Document): BaseEntrypointOptions {
  */
 async function getPopupEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<PopupEntrypoint> {
   const content = await fs.readFile(inputPath, 'utf-8');
   const { document } = parseHTML(content);
@@ -273,7 +247,6 @@ async function getPopupEntrypoint(
     options,
     inputPath,
     outputDir: config.outDir,
-    skipped,
   };
 }
 
@@ -283,7 +256,7 @@ async function getPopupEntrypoint(
  */
 async function getOptionsEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<OptionsEntrypoint> {
   const content = await fs.readFile(inputPath, 'utf-8');
   const { document } = parseHTML(content);
@@ -317,7 +290,6 @@ async function getOptionsEntrypoint(
     options,
     inputPath,
     outputDir: config.outDir,
-    skipped,
   };
 }
 
@@ -327,7 +299,7 @@ async function getOptionsEntrypoint(
  */
 async function getUnlistedPageEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<GenericEntrypoint> {
   const content = await fs.readFile(inputPath, 'utf-8');
   const { document } = parseHTML(content);
@@ -338,7 +310,6 @@ async function getUnlistedPageEntrypoint(
     inputPath,
     outputDir: config.outDir,
     options: getHtmlBaseOptions(document),
-    skipped,
   };
 }
 
@@ -348,7 +319,7 @@ async function getUnlistedPageEntrypoint(
  */
 async function getUnlistedScriptEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<GenericEntrypoint> {
   const defaultExport = await importEntrypointFile<UnlistedScriptDefinition>(
     inputPath,
@@ -367,7 +338,6 @@ async function getUnlistedScriptEntrypoint(
     inputPath,
     outputDir: config.outDir,
     options,
-    skipped,
   };
 }
 
@@ -376,7 +346,7 @@ async function getUnlistedScriptEntrypoint(
  */
 async function getBackgroundEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<BackgroundEntrypoint> {
   let options: Omit<BackgroundDefinition, 'main'> = {};
   if (inputPath !== VIRTUAL_NOOP_BACKGROUND_MODULE_ID) {
@@ -402,7 +372,6 @@ async function getBackgroundEntrypoint(
       type: resolvePerBrowserOption(options.type, config.browser),
       persistent: resolvePerBrowserOption(options.persistent, config.browser),
     },
-    skipped,
   };
 }
 
@@ -411,7 +380,7 @@ async function getBackgroundEntrypoint(
  */
 async function getContentScriptEntrypoint(
   config: InternalConfig,
-  { inputPath, name, skipped }: EntrypointInfo,
+  { inputPath, name }: EntrypointInfo,
 ): Promise<ContentScriptEntrypoint> {
   const { main: _, ...options } =
     await importEntrypointFile<ContentScriptDefinition>(inputPath, config);
@@ -426,7 +395,6 @@ async function getContentScriptEntrypoint(
     inputPath,
     outputDir: resolve(config.outDir, CONTENT_SCRIPT_OUT_DIR),
     options,
-    skipped,
   };
 }
 

src/core/utils/building/generate-wxt-dir.ts

@@ -6,9 +6,9 @@ import { getEntrypointBundlePath } from '~/core/utils/entrypoints';
 import { getUnimportOptions } from '~/core/utils/unimport';
 import { getEntrypointGlobals, getGlobals } from '~/core/utils/globals';
 import { normalizePath } from '~/core/utils/paths';
-import path from 'node:path';
-import { Message, parseI18nMessages } from '~/core/utils/i18n';
 import { writeFileIfDifferent, getPublicFiles } from '~/core/utils/fs';
+import glob from 'fast-glob';
+import { Message, PREDEFINED_MESSAGES, readMessagesFile } from '~/i18n/node';
 
 /**
  * Generate and write all the files inside the `InternalConfig.typesDir` directory.
@@ -79,10 +79,8 @@ import "wxt/browser";
 declare module "wxt/browser" {
   export type PublicPath =
 {{ union }}
-  type HtmlPublicPath = Extract<PublicPath, \`\${string}.html\`>
   export interface WxtRuntime extends Runtime.Static {
     getURL(path: PublicPath): string;
-    getURL(path: \`\${HtmlPublicPath}\${string}\`): string;
   }
 }
 `;
@@ -115,30 +113,38 @@ declare module "wxt/browser" {
   }
 
   export interface WxtI18n extends I18n.Static {
-{{ overrides }}
+{{ browserOverrides }}
+  }
+}
+
+declare module "wxt/i18n" {
+  export interface WxtMessageSchema {
+    t: {
+{{ translationTOverrides }}
+    };
+    tp: {
+{{ translationTpOverrides }}
+    };
   }
 }
 `;
 
   let messages: Message[];
   if (defaultLocale) {
-    const defaultLocalePath = path.resolve(
-      config.publicDir,
-      '_locales',
-      defaultLocale,
-      'messages.json',
-    );
-    const content = JSON.parse(await fs.readFile(defaultLocalePath, 'utf-8'));
-    messages = parseI18nMessages(content);
+    const [defaultLocalePath] = await glob(`${defaultLocale}.*`, {
+      cwd: config.localesDir,
+      absolute: true,
+    });
+    messages = await readMessagesFile(defaultLocalePath);
   } else {
-    messages = parseI18nMessages({});
+    messages = PREDEFINED_MESSAGES;
   }
 
   const overrides = messages.map((message) => {
     return `    /**
-     * ${message.description ?? 'No message description.'}
+     * ${message.entry.description ?? 'No message description.'}
      *
-     * "${message.message}"
+     * "${message.entry.message}"
      */
     getMessage(
       messageName: "${message.name}",
@@ -148,7 +154,22 @@ declare module "wxt/browser" {
   });
   await writeFileIfDifferent(
     filePath,
-    template.replace('{{ overrides }}', overrides.join('\n')),
+    template
+      .replace('{{ browserOverrides }}', overrides.join('\n'))
+      .replace(
+        '{{ translationTOverrides }}',
+        messages
+          .filter((message) => !message.isPlural)
+          .map((message) => `      "${message.name}": any;`)
+          .join('\n'),
+      )
+      .replace(
+        '{{ translationTpOverrides }}',
+        messages
+          .filter((message) => message.isPlural)
+          .map((message) => `      "${message.name}": any;`)
+          .join('\n'),
+      ),
   );
 
   return filePath;

src/core/utils/building/get-internal-config.ts

@@ -72,10 +72,8 @@ export async function getInternalConfig(
     srcDir,
     mergedConfig.entrypointsDir ?? 'entrypoints',
   );
-  const filterEntrypoints = !!mergedConfig.filterEntrypoints?.length
-    ? new Set(mergedConfig.filterEntrypoints)
-    : undefined;
   const publicDir = path.resolve(srcDir, mergedConfig.publicDir ?? 'public');
+  const localesDir = path.resolve(srcDir, mergedConfig.localesDir ?? 'locales');
   const typesDir = path.resolve(wxtDir, 'types');
   const outBaseDir = path.resolve(root, mergedConfig.outDir ?? '.output');
   const outDir = path.resolve(outBaseDir, `${browser}-mv${manifestVersion}`);
@@ -104,7 +102,6 @@ export async function getInternalConfig(
     command,
     debug,
     entrypointsDir,
-    filterEntrypoints,
     env,
     fsCache: createFsCache(wxtDir),
     imports: mergedConfig.imports ?? {},
@@ -115,6 +112,7 @@ export async function getInternalConfig(
     outBaseDir,
     outDir,
     publicDir,
+    localesDir,
     root,
     runnerConfig,
     srcDir,
@@ -195,13 +193,12 @@ function mergeInlineConfig(
     configFile: inlineConfig.configFile,
     debug: inlineConfig.debug ?? userConfig.debug,
     entrypointsDir: inlineConfig.entrypointsDir ?? userConfig.entrypointsDir,
-    filterEntrypoints:
-      inlineConfig.filterEntrypoints ?? userConfig.filterEntrypoints,
     imports,
     logger: inlineConfig.logger ?? userConfig.logger,
     manifest,
     mode: inlineConfig.mode ?? userConfig.mode,
     publicDir: inlineConfig.publicDir ?? userConfig.publicDir,
+    localesDir: inlineConfig.localesDir ?? userConfig.localesDir,
     runner,
     srcDir: inlineConfig.srcDir ?? userConfig.srcDir,
     outDir: inlineConfig.outDir ?? userConfig.outDir,

src/core/utils/building/import-entrypoint.ts

@@ -2,7 +2,7 @@ import createJITI, { TransformOptions as JitiTransformOptions } from 'jiti';
 import { InternalConfig } from '~/types';
 import { createUnimport } from 'unimport';
 import fs from 'fs-extra';
-import { relative, resolve } from 'node:path';
+import { resolve } from 'node:path';
 import { getUnimportOptions } from '~/core/utils/unimport';
 import { removeProjectImportStatements } from '~/core/utils/strings';
 import { normalizePath } from '~/core/utils/paths';
@@ -89,17 +89,8 @@ export async function importEntrypointFile<T>(
     const res = await jiti(path);
     return res.default;
   } catch (err) {
-    if (err instanceof ReferenceError) {
-      // "XXX is not defined" - usually due to WXT removing imports
-      const variableName = err.message.replace(' is not defined', '');
-      const filePath = relative(config.root, path);
-      throw Error(
-        `${filePath}: Cannot use imported variable "${variableName}" outside the main function. See https://wxt.dev/guide/entrypoints.html#side-effects`,
-        { cause: err },
-      );
-    } else {
-      throw err;
-    }
+    config.logger.error(err);
+    throw err;
   }
 }
 

src/core/utils/i18n.ts

@@ -1,52 +0,0 @@
-export interface Message {
-  name: string;
-  message: string;
-  description?: string;
-}
-
-const predefinedMessages = {
-  '@@extension_id': {
-    message: '<browser.runtime.id>',
-    description:
-      "The extension or app ID; you might use this string to construct URLs for resources inside the extension. Even unlocalized extensions can use this message.\nNote: You can't use this message in a manifest file.",
-  },
-  '@@ui_locale': {
-    message: '<browser.i18n.getUiLocale()>',
-    description: '',
-  },
-  '@@bidi_dir': {
-    message: '<ltr|rtl>',
-    description:
-      'The text direction for the current locale, either "ltr" for left-to-right languages such as English or "rtl" for right-to-left languages such as Japanese.',
-  },
-  '@@bidi_reversed_dir': {
-    message: '<rtl|ltr>',
-    description:
-      'If the @@bidi_dir is "ltr", then this is "rtl"; otherwise, it\'s "ltr".',
-  },
-  '@@bidi_start_edge': {
-    message: '<left|right>',
-    description:
-      'If the @@bidi_dir is "ltr", then this is "left"; otherwise, it\'s "right".',
-  },
-  '@@bidi_end_edge': {
-    message: '<right|left>',
-    description:
-      'If the @@bidi_dir is "ltr", then this is "right"; otherwise, it\'s "left".',
-  },
-};
-
-/**
- * Get a list of all messages and their metadata from JSON file contents.
- *
- * @param messagesJson The contents of a `_locales/en/messages.json` file.
- */
-export function parseI18nMessages(messagesJson: object): Message[] {
-  return Object.entries({
-    ...predefinedMessages,
-    ...messagesJson,
-  }).map<Message>(([name, details]) => ({
-    name,
-    ...details,
-  }));
-}

src/core/utils/testing/fake-objects.ts

@@ -59,7 +59,7 @@ export const fakeContentScriptEntrypoint =
     name: faker.string.alpha(),
     options: {
       matches: [],
-      matchAboutBlank: faker.datatype.boolean(),
+      matchAboutBlank: faker.helpers.arrayElement([true, false, undefined]),
       matchOriginAsFallback: faker.helpers.arrayElement([
         true,
         false,
@@ -73,7 +73,6 @@ export const fakeContentScriptEntrypoint =
       ]),
     },
     outputDir: fakeDir('.output'),
-    skipped: faker.datatype.boolean(),
   }));
 
 export const fakeBackgroundEntrypoint = fakeObjectCreator<BackgroundEntrypoint>(
@@ -82,11 +81,10 @@ export const fakeBackgroundEntrypoint = fakeObjectCreator<BackgroundEntrypoint>(
     inputPath: 'entrypoints/background.ts',
     name: 'background',
     options: {
-      persistent: faker.datatype.boolean(),
+      persistent: faker.helpers.arrayElement([true, false, undefined]),
       type: faker.helpers.maybe(() => 'module'),
     },
     outputDir: fakeDir('.output'),
-    skipped: faker.datatype.boolean(),
   }),
 );
 
@@ -97,7 +95,6 @@ export const fakeUnlistedScriptEntrypoint =
     name: faker.string.alpha(),
     outputDir: fakeDir('.output'),
     options: {},
-    skipped: faker.datatype.boolean(),
   }));
 
 export const fakeOptionsEntrypoint = fakeObjectCreator<OptionsEntrypoint>(
@@ -107,11 +104,10 @@ export const fakeOptionsEntrypoint = fakeObjectCreator<OptionsEntrypoint>(
     name: 'options',
     outputDir: fakeDir('.output'),
     options: {
-      browserStyle: faker.datatype.boolean(),
-      chromeStyle: faker.datatype.boolean(),
-      openInTab: faker.datatype.boolean(),
+      browserStyle: faker.helpers.arrayElement([true, false, undefined]),
+      chromeStyle: faker.helpers.arrayElement([true, false, undefined]),
+      openInTab: faker.helpers.arrayElement([true, false, undefined]),
     },
-    skipped: faker.datatype.boolean(),
   }),
 );
 
@@ -138,7 +134,6 @@ export const fakePopupEntrypoint = fakeObjectCreator<PopupEntrypoint>(() => ({
       undefined,
     ]),
   },
-  skipped: faker.datatype.boolean(),
 }));
 
 export const fakeGenericEntrypoint = fakeObjectCreator<GenericEntrypoint>(
@@ -157,7 +152,6 @@ export const fakeGenericEntrypoint = fakeObjectCreator<GenericEntrypoint>(
     name: faker.string.alpha(),
     outputDir: fakeDir('.output'),
     options: {},
-    skipped: faker.datatype.boolean(),
   }),
 );
 
@@ -217,6 +211,7 @@ export const fakeInternalConfig = fakeObjectCreator<InternalConfig>(() => {
     outBaseDir: fakeDir(),
     outDir: fakeDir(),
     publicDir: fakeDir(),
+    localesDir: fakeDir(),
     root: fakeDir(),
     runnerConfig: {
       config: {},

src/core/utils/unimport.ts

@@ -12,6 +12,7 @@ export function getUnimportOptions(
     imports: [
       { name: 'defineConfig', from: 'wxt' },
       { name: 'fakeBrowser', from: 'wxt/testing' },
+      { name: 'i18n', from: 'wxt/i18n' },
     ],
     presets: [
       { package: 'wxt/client' },

src/i18n/__tests__/client.test.ts

@@ -0,0 +1,165 @@
+import { describe, it, vi, expect } from 'vitest';
+import { createExtensionI18n } from '../client';
+import { fakeBrowser } from '@webext-core/fake-browser';
+
+let getMessageMock = vi.fn();
+fakeBrowser.i18n.getMessage = getMessageMock;
+
+describe('createExtensionI18n', () => {
+  describe('t', () => {
+    it('should return the text from browsesr.i18n.getMessage', () => {
+      const expected = 'Hello world';
+      const i18n = createExtensionI18n();
+      getMessageMock.mockReturnValue(expected);
+
+      const actual = i18n.t('key', ['']);
+
+      expect(actual).toBe(expected);
+    });
+
+    it("should return a blank string when the message doesn't exist", () => {
+      const i18n = createExtensionI18n();
+      // browser.i18n.getMessage returns a blank string when the message doesn't exist
+      getMessageMock.mockReturnValue('');
+
+      const actual = i18n.t('unknown-key');
+
+      expect(actual).toBe('');
+    });
+
+    it('should pass substitutions in correctly', () => {
+      const i18n = createExtensionI18n();
+      const key = 'key';
+      const subs = ['1', 'two'];
+
+      i18n.t(key, subs);
+
+      expect(getMessageMock).toBeCalledWith(key, subs);
+    });
+  });
+
+  describe('tp', () => {
+    it.each([
+      [0, '0 items'],
+      [1, '1 items'],
+      [2, '2 items'],
+      [3, '3 items'],
+    ])(
+      'should return the correct string for format "{n}" and count=%s',
+      (count, expected) => {
+        const i18n = createExtensionI18n();
+        getMessageMock.mockReturnValue(`${count} items`);
+
+        const actual = i18n.tp('key', count, [String(count)]);
+
+        expect(actual).toBe(expected);
+      },
+    );
+
+    it.each([
+      [0, '0 items'],
+      [1, '1 item'],
+      [2, '2 items'],
+      [3, '3 items'],
+    ])(
+      'should return the correct string for format "{1} | {n}" and count=%s',
+      (count, expected) => {
+        const i18n = createExtensionI18n();
+        getMessageMock.mockReturnValue(`1 item | ${count} items`);
+
+        const actual = i18n.tp('key', count, [String(count)]);
+
+        expect(actual).toBe(expected);
+      },
+    );
+
+    it.each([
+      [0, '0 items'],
+      [1, '1 item'],
+      [2, '2 items'],
+      [3, '3 items'],
+    ])(
+      'should return the correct string for format "{0} | {1} | {n}" and count=%s',
+      (count, expected) => {
+        const i18n = createExtensionI18n();
+        getMessageMock.mockReturnValue(`0 items | 1 item | ${count} items`);
+
+        const actual = i18n.tp('key', count, [String(count)]);
+
+        expect(actual).toBe(expected);
+      },
+    );
+
+    it('should pass substitutions in correctly', () => {
+      const i18n = createExtensionI18n();
+      const key = 'key';
+      const count = 4;
+      const subs = ['1', 'two'];
+      getMessageMock.mockReturnValue(`0 items | 1 item | ${count} items`);
+
+      i18n.tp(key, count, subs);
+
+      expect(getMessageMock).toBeCalledWith(key, subs);
+    });
+  });
+
+  it('should support custom types', () => {
+    const i18n = createExtensionI18n<{
+      t: {
+        singularNoSubs: undefined;
+        singularOneSub: [name: string];
+        singularTwoSubs: [string, string];
+      };
+      tp: {
+        pluralNoSubs: undefined;
+        pluralOneSub: [name: string];
+        pluralTwoSubs: [string, string];
+      };
+    }>();
+    getMessageMock.mockReturnValue('');
+
+    i18n.t('singularNoSubs');
+    // @ts-expect-error
+    i18n.t('singularNoSubs', ['1', '2']);
+
+    i18n.t('singularOneSub', ['one']);
+    // @ts-expect-error
+    i18n.t('singularOneSub');
+
+    i18n.t('singularTwoSubs', ['one', 'two']);
+    // @ts-expect-error
+    i18n.t('singularTwoSubs', ['one']);
+    // @ts-expect-error
+    i18n.t('singularTwoSubs');
+
+    // @ts-expect-error
+    i18n.t('pluralNoSubs');
+    // @ts-expect-error
+    i18n.t('pluralOneSub');
+    // @ts-expect-error
+    i18n.t('pluralTwoSubs');
+
+    i18n.tp('pluralNoSubs', 0);
+    // @ts-expect-error
+    i18n.tp('pluralNoSubs', 0, ['1', '2']);
+    // @ts-expect-error
+    i18n.tp('pluralNoSubs');
+
+    i18n.tp('pluralOneSub', 0, ['one']);
+    // @ts-expect-error
+    i18n.tp('pluralOneSub', 0);
+
+    i18n.tp('pluralTwoSubs', 0, ['one', 'two']);
+    // @ts-expect-error
+    i18n.tp('pluralTwoSubs', 0, ['one']);
+    // @ts-expect-error
+    i18n.tp('pluralTwoSubs', 0);
+
+    // @ts-expect-error
+    i18n.tp('singularNoSubs');
+    // @ts-expect-error
+    i18n.tp('singularOneSub');
+    // @ts-expect-error
+    i18n.tp('singularTwoSubs');
+  });
+});

src/i18n/__tests__/fixtures/input.yml

@@ -0,0 +1,13 @@
+simple: Hello world!
+manifestStyle:
+  message: This is the translated text
+  description: This is a description to give translators more context (it's never translated)
+interpolation: Hello $1, my name is $2
+some:
+  nested:
+    translation: You can nest translations inside deep objects
+escapeTheDollarSign: You owe me $$100
+pluralForm:
+  n: $1 items
+  1: 1 item
+  0: Zero items

src/i18n/__tests__/fixtures/manifest.json

@@ -0,0 +1,21 @@
+{
+  "simple": {
+    "message": "Hello world!"
+  },
+  "manifestStyle": {
+    "message": "This is the translated text",
+    "description": "This is a description to give translators more context (it's never translated)"
+  },
+  "interpolation": {
+    "message": "Hello $1, my name is $2"
+  },
+  "some_nested_translation": {
+    "message": "You can nest translations inside deep objects"
+  },
+  "escapeTheDollarSign": {
+    "message": "You owe me $$100"
+  },
+  "pluralForm": {
+    "message": "Zero items | 1 item | $1 items"
+  }
+}

src/i18n/__tests__/fixtures/messages.json

@@ -0,0 +1,87 @@
+[
+  {
+    "entry": {
+      "message": "Hello world!"
+    },
+    "name": "simple"
+  },
+  {
+    "entry": {
+      "description": "This is a description to give translators more context (it's never translated)",
+      "message": "This is the translated text"
+    },
+    "name": "manifestStyle"
+  },
+  {
+    "entry": {
+      "message": "Hello $1, my name is $2"
+    },
+    "name": "interpolation"
+  },
+  {
+    "entry": {
+      "message": "You can nest translations inside deep objects"
+    },
+    "name": "some_nested_translation"
+  },
+  {
+    "entry": {
+      "message": "You owe me $$100"
+    },
+    "name": "escapeTheDollarSign"
+  },
+  {
+    "entry": {
+      "message": "Zero items | 1 item | $1 items"
+    },
+    "isPlural": true,
+    "name": "pluralForm"
+  },
+  {
+    "entry": {
+      "description": "The extension or app ID; you might use this string to construct URLs for resources inside the extension. Even unlocalized extensions can use this message.\nNote: You can't use this message in a manifest file.",
+      "message": "<browser.runtime.id>"
+    },
+    "isBuiltin": true,
+    "name": "@@extension_id"
+  },
+  {
+    "entry": {
+      "message": "<browser.i18n.getUiLocale()>"
+    },
+    "isBuiltin": true,
+    "name": "@@ui_locale"
+  },
+  {
+    "entry": {
+      "description": "The text direction for the current locale, either \"ltr\" for left-to-right languages such as English or \"rtl\" for right-to-left languages such as Japanese.",
+      "message": "<ltr|rtl>"
+    },
+    "isBuiltin": true,
+    "name": "@@bidi_dir"
+  },
+  {
+    "entry": {
+      "description": "If the @@bidi_dir is \"ltr\", then this is \"rtl\"; otherwise, it's \"ltr\".",
+      "message": "<rtl|ltr>"
+    },
+    "isBuiltin": true,
+    "name": "@@bidi_reversed_dir"
+  },
+  {
+    "entry": {
+      "description": "If the @@bidi_dir is \"ltr\", then this is \"left\"; otherwise, it's \"right\".",
+      "message": "<left|right>"
+    },
+    "isBuiltin": true,
+    "name": "@@bidi_start_edge"
+  },
+  {
+    "entry": {
+      "description": "If the @@bidi_dir is \"ltr\", then this is \"right\"; otherwise, it's \"left\".",
+      "message": "<right|left>"
+    },
+    "isBuiltin": true,
+    "name": "@@bidi_end_edge"
+  }
+]

src/i18n/__tests__/node.test.ts

@@ -0,0 +1,29 @@
+import { readFile } from 'node:fs/promises';
+import { resolve } from 'node:path';
+import { describe, it, expect } from 'vitest';
+import { convertMessagesToManifest, readMessagesFile } from '../node';
+
+const inputFile = resolve(__dirname, 'fixtures/input.yml');
+const messagesFile = resolve(__dirname, 'fixtures/messages.json');
+const manifestFile = resolve(__dirname, 'fixtures/manifest.json');
+
+describe('I18n Node Utils', () => {
+  describe('readMessagesFile', () => {
+    it('should return all available messages and metadata', async () => {
+      const expected = JSON.parse(await readFile(messagesFile, 'utf-8'));
+      const actual = await readMessagesFile(inputFile);
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  describe('convertMessagesToManifest', () => {
+    it('should return all available messages and metadata', async () => {
+      const input = JSON.parse(await readFile(messagesFile, 'utf-8'));
+      const expected = JSON.parse(await readFile(manifestFile, 'utf-8'));
+
+      const actual = convertMessagesToManifest(input);
+
+      expect(actual).toEqual(expected);
+    });
+  });
+});

src/i18n/client.ts

@@ -0,0 +1,75 @@
+import { browser } from '~/browser';
+
+export interface DefaultMessageSchema {
+  t: {
+    [key: string]: string[] | undefined;
+  };
+  tp: {
+    [key: string]: string[] | undefined;
+  };
+}
+
+export function createExtensionI18n<
+  TMessageSchema = unknown,
+>(): ExtensionI18n<TMessageSchema> {
+  const untyped: UntypedExtensionI18n = {
+    t(key, substitutions) {
+      return browser.i18n.getMessage(key, substitutions);
+    },
+    tp(key, count, substitutions) {
+      const plural = browser.i18n
+        .getMessage(key as string, substitutions)
+        .split(' | ');
+
+      // "n items"
+      if (plural.length === 1) return plural[0];
+
+      // "1 item | n items"
+      if (plural.length === 2) {
+        if (count === 1) return plural[0];
+        return plural[1];
+      }
+
+      // "0 items | 1 item | n items"
+      if (count === 0 || count === 1) return plural[count];
+      return plural[2];
+    },
+  };
+  return untyped as ExtensionI18n<TMessageSchema>;
+}
+
+export type ExtensionI18n<TMessageSchema> =
+  TMessageSchema extends DefaultMessageSchema
+    ? TypedExtensionI18n<TMessageSchema>
+    : UntypedExtensionI18n;
+
+export interface TypedExtensionI18n<
+  TMessageSchema extends DefaultMessageSchema,
+> {
+  t<TKey extends KeysWithoutSub<TMessageSchema['t']>>(key: TKey): string;
+  t<TKey extends KeysWithSub<TMessageSchema['t']>>(
+    key: TKey,
+    substitutions: TMessageSchema['t'][TKey],
+  ): string;
+
+  tp<TKey extends KeysWithoutSub<TMessageSchema['tp']>>(
+    key: TKey,
+    count: number,
+  ): string;
+  tp<TKey extends KeysWithSub<TMessageSchema['tp']>>(
+    key: TKey,
+    count: number,
+    substitutions: TMessageSchema['tp'][TKey],
+  ): string;
+}
+
+export interface UntypedExtensionI18n {
+  t(key: string, substitutions?: string[]): string;
+  tp(key: string, count: number, substitutions?: string[]): string;
+}
+
+type FilterKeys<TObject, TFilterType> = {
+  [K in keyof TObject]-?: TObject[K] extends TFilterType ? K : never;
+}[keyof TObject];
+type KeysWithSub<TObject> = FilterKeys<TObject, string[]>;
+type KeysWithoutSub<TObject> = FilterKeys<TObject, undefined>;

src/i18n/index.ts

@@ -0,0 +1,21 @@
+/**
+ * Simple, type-safe alternative to `browser.i18n.getMessage` with support for placeholders and plurals.
+ *
+ * See [the guide](https://wxt.dev/guide/localization.html) for more information.
+ *
+ * @module wxt/i18n
+ */
+
+import { DefaultMessageSchema, createExtensionI18n } from './client';
+
+export interface WxtMessageSchema extends DefaultMessageSchema {
+  // Overriden per-project
+}
+
+export const i18n = createExtensionI18n<WxtMessageSchema>();
+export {
+  DefaultMessageSchema,
+  ExtensionI18n,
+  TypedExtensionI18n,
+  UntypedExtensionI18n,
+} from './client';

src/i18n/node.ts

@@ -0,0 +1,210 @@
+import { readFile } from 'node:fs/promises';
+import JSON5 from 'json5';
+import YAML from 'yaml';
+
+/**
+ * Convert a file containing localized text in WXT's custom format into valid extension manifest
+ * format.
+ */
+export async function readMessagesFile(file: string): Promise<Message[]> {
+  const text = await readFile(file, 'utf-8');
+  return readMessagesText(text);
+}
+
+/**
+ * Convert a string containing localized text in WXT's custom format into valid extension manifest
+ * format.
+ */
+export function readMessagesText(text: string): Message[] {
+  const parsers: Array<(text: string) => any> = [
+    JSON.parse,
+    JSON5.parse,
+    YAML.parse,
+  ];
+
+  for (const parse of parsers) {
+    try {
+      const result = parse(text);
+      if (typeof result === 'object') {
+        return readMessagesObject(result);
+      }
+    } catch {
+      continue;
+    }
+  }
+
+  throw Error('I18n messages text is not valid JSON, JSON5, or YAML');
+}
+
+/**
+ * Convert an object containing localized text in WXT's custom format into valid extension manifest
+ * format.
+ */
+export function readMessagesObject(input: ExtensionI18nSchema): Message[] {
+  const messagesFromInput = findEntries([], input);
+  return [...messagesFromInput, ...PREDEFINED_MESSAGES];
+}
+
+export function convertMessagesToManifest(
+  messages: Message[],
+): RawExtensionI18nSchema {
+  return messages
+    .filter((message) => !message.isBuiltin)
+    .reduce<RawExtensionI18nSchema>((schema, { name, entry }) => {
+      schema[name] = entry;
+      return schema;
+    }, {});
+}
+
+function findEntries(
+  keyPath: string[],
+  input: ExtensionI18nSchema | ExtensionI18nEntry,
+): Message[] {
+  const name = keyPath.join('_');
+  if (isBasicEntry(input))
+    return [
+      {
+        name,
+        entry: { message: input },
+      },
+    ];
+  if (isManifestEntry(input))
+    return [
+      {
+        name,
+        entry: input,
+      },
+    ];
+  if (isPluralEntry(input))
+    return [
+      {
+        name,
+        entry: {
+          message: Object.values(input).join(' | '),
+        },
+        isPlural: true,
+      },
+    ];
+
+  return Object.entries(input).reduce<Message[]>((items, [key, child]) => {
+    const nestedEntries = findEntries(keyPath.concat(key), child);
+    return [...items, ...nestedEntries];
+  }, []);
+}
+
+function isBasicEntry(
+  entry: ExtensionI18nSchema | ExtensionI18nEntry,
+): entry is ExtensionI18nBasicEntry {
+  return typeof entry === 'string';
+}
+
+function isManifestEntry(
+  entry: ExtensionI18nSchema | ExtensionI18nEntry,
+): entry is ExtensionI18nManifestEntry {
+  const keys = Object.keys(entry);
+  if (keys.length < 1 || keys.length > 3) return false;
+
+  const knownKeys = new Set(['message', 'placeholders', 'description']);
+  const unknownKeys = keys.filter((key) => !knownKeys.has(key));
+  return unknownKeys.length === 0;
+}
+
+function isPluralEntry(
+  entry: ExtensionI18nSchema | ExtensionI18nEntry,
+): entry is ExtensionI18nPluralEntry {
+  const keys = Object.keys(entry);
+  if (keys.length === 0) return false;
+
+  const invalidKeys = keys.filter((key) => key !== 'n' && isNaN(Number(key)));
+  return invalidKeys.length === 0;
+}
+
+export const PREDEFINED_MESSAGES: Message[] = [
+  {
+    name: '@@extension_id',
+    isBuiltin: true,
+    entry: {
+      message: '<browser.runtime.id>',
+      description:
+        "The extension or app ID; you might use this string to construct URLs for resources inside the extension. Even unlocalized extensions can use this message.\nNote: You can't use this message in a manifest file.",
+    },
+  },
+  {
+    name: '@@ui_locale',
+    isBuiltin: true,
+    entry: {
+      message: '<browser.i18n.getUiLocale()>',
+    },
+  },
+  {
+    name: '@@bidi_dir',
+    isBuiltin: true,
+    entry: {
+      message: '<ltr|rtl>',
+      description:
+        'The text direction for the current locale, either "ltr" for left-to-right languages such as English or "rtl" for right-to-left languages such as Japanese.',
+    },
+  },
+  {
+    name: '@@bidi_reversed_dir',
+    isBuiltin: true,
+    entry: {
+      message: '<rtl|ltr>',
+      description:
+        'If the @@bidi_dir is "ltr", then this is "rtl"; otherwise, it\'s "ltr".',
+    },
+  },
+  {
+    name: '@@bidi_start_edge',
+    isBuiltin: true,
+    entry: {
+      message: '<left|right>',
+      description:
+        'If the @@bidi_dir is "ltr", then this is "left"; otherwise, it\'s "right".',
+    },
+  },
+  {
+    name: '@@bidi_end_edge',
+    isBuiltin: true,
+    entry: {
+      message: '<right|left>',
+      description:
+        'If the @@bidi_dir is "ltr", then this is "right"; otherwise, it\'s "left".',
+    },
+  },
+];
+
+export type RawExtensionI18nSchema = Record<string, RawExtensionI18nEntry>;
+export interface RawExtensionI18nEntry {
+  message: string;
+  description?: string;
+  placeholders?: Record<
+    string,
+    {
+      content: string;
+      example?: string;
+    }
+  >;
+}
+
+export type ExtensionI18nBasicEntry = string;
+export type ExtensionI18nManifestEntry = RawExtensionI18nEntry;
+export type ExtensionI18nPluralEntry = {
+  n: string;
+  [i: number]: string;
+};
+export type ExtensionI18nEntry =
+  | ExtensionI18nBasicEntry
+  | ExtensionI18nManifestEntry
+  | ExtensionI18nPluralEntry;
+
+export interface ExtensionI18nSchema {
+  [name: string]: ExtensionI18nSchema | ExtensionI18nEntry;
+}
+
+export interface Message {
+  name: string;
+  entry: RawExtensionI18nEntry;
+  isPlural?: boolean;
+  isBuiltin?: boolean;
+}

src/types/external.ts

@@ -27,16 +27,16 @@ export interface InlineConfig {
    * @default "${config.root}/public"
    */
   publicDir?: string;
+  /**
+   * Directory containing localization files used for translation.
+   *
+   * @default "${config.srcDir}/locales"
+   */
+  localesDir?: string;
   /**
    * @default "${config.srcDir}/entrypoints"
    */
   entrypointsDir?: string;
-  /**
-   * A list of entrypoint names (`"popup"`, `"options"`, etc.) to build. Will speed up the build if
-   * your extension has lots of entrypoints, and you don't need to build all of them to develop a
-   * feature.
-   */
-  filterEntrypoints?: string[];
   /**
    * Output directory that stored build folders and ZIPs.
    *
@@ -383,7 +383,6 @@ export interface BaseEntrypoint {
    */
   outputDir: string;
   options: BaseEntrypointOptions;
-  skipped: boolean;
 }
 
 export interface GenericEntrypoint extends BaseEntrypoint {

src/types/internal.ts

@@ -18,10 +18,10 @@ export interface InternalConfig {
   root: string;
   srcDir: string;
   publicDir: string;
+  localesDir: string;
   wxtDir: string;
   typesDir: string;
   entrypointsDir: string;
-  filterEntrypoints?: Set<string>;
   outBaseDir: string;
   outDir: string;
   debug: boolean;