bump version for early release

e2e/tests/output-structure.test.ts

@@ -362,11 +362,13 @@ describe('Output Directory Structure', () => {
           function logHello(name) {
             console.log(\`Hello \${name}!\`);
           }
+          _background;
           const definition = defineBackground({
             main() {
               logHello("background");
             }
           });
+          _background;
           chrome;
           function print(method, ...args) {
             return;
@@ -389,6 +391,7 @@ describe('Output Directory Structure', () => {
             throw err;
           }
         })();
+        _background;
         "
       `);
   });

package.json

@@ -1,7 +1,7 @@
 {
   "name": "wxt",
   "type": "module",
-  "version": "0.17.12",
+  "version": "0.17.13-alpha1",
   "description": "Next gen framework for developing web extensions",
   "engines": {
     "node": ">=18",

pnpm-lock.yaml

@@ -4919,8 +4919,8 @@ packages:
       loose-envify: 1.4.0
     dev: false
 
-  /scule@1.0.0:
-    resolution: {integrity: sha512-4AsO/FrViE/iDNEPaAQlb77tf0csuq27EsVpy6ett584EcRTp6pTDLoGWVxCD77y5iU5FauOvhsI4o1APwPoSQ==}
+  /scule@1.3.0:
+    resolution: {integrity: sha512-6FtHJEvt+pVMIB9IBY+IcCJ6Z5f1iQnytgyfKMhDKgmzYG+TeH/wx1y3l27rshSbLiSanrR9ffZDrEsmjlQF2g==}
     dev: false
 
   /semver-diff@4.0.0:
@@ -5550,7 +5550,7 @@ packages:
       mlly: 1.4.2
       pathe: 1.1.1
       pkg-types: 1.0.3
-      scule: 1.0.0
+      scule: 1.3.0
       strip-literal: 1.3.0
       unplugin: 1.5.0
     transitivePeerDependencies:

src/core/builders/vite/index.ts

@@ -19,6 +19,7 @@ import {
 } from '~/core/utils/virtual-modules';
 import { Hookable } from 'hookable';
 import { toArray } from '~/core/utils/arrays';
+import { safeVarName } from '~/core/utils/strings';
 
 export async function createViteBuilder(
   wxtConfig: ResolvedConfig,
@@ -87,14 +88,22 @@ export async function createViteBuilder(
       plugins.push(wxtPlugins.cssEntrypoints(entrypoint, wxtConfig));
     }
 
+    const iifeReturnValueName = safeVarName(entrypoint.name);
     const libMode: vite.UserConfig = {
       mode: wxtConfig.mode,
       plugins,
+      esbuild: {
+        // Add a footer with the returned value so it can return values to `scripting.executeScript`
+        // Footer is added apart of esbuild to make sure it's not minified. It
+        // get's removed if added to `build.rollupOptions.output.footer`
+        // See https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/scripting/executeScript#return_value
+        footer: iifeReturnValueName + ';',
+      },
       build: {
         lib: {
           entry,
           formats: ['iife'],
-          name: '_',
+          name: iifeReturnValueName,
           fileName: entrypoint.name,
         },
         rollupOptions: {

src/core/utils/strings.ts

@@ -5,6 +5,14 @@ export function kebabCaseAlphanumeric(str: string): string {
     .replace(/\s+/g, '-'); // Replace spaces with hyphens
 }
 
+/**
+ * Return a safe variable name for a given string.
+ */
+export function safeVarName(str: string): string {
+  // _ prefix to ensure it doesn't start with a number
+  return '_' + kebabCaseAlphanumeric(str).replace('-', '_');
+}
+
 /**
  * Removes import statements from the top of a file. Keeps import.meta and inline, async `import()`
  * calls.

src/types/index.ts

@@ -737,16 +737,24 @@ export interface IsolatedWorldContentScriptDefinition
   extends IsolatedWorldContentScriptEntrypointOptions {
   /**
    * Main function executed when the content script is loaded.
+   *
+   * When running a content script with `browser.scripting.executeScript`,
+   * values returned from this function will be returned in the `executeScript`
+   * result as well. Otherwise returning a value does nothing.
    */
-  main(ctx: ContentScriptContext): void | Promise<void>;
+  main(ctx: ContentScriptContext): any | Promise<any>;
 }
 
 export interface MainWorldContentScriptDefinition
   extends MainWorldContentScriptEntrypointOptions {
   /**
    * Main function executed when the content script is loaded.
+   *
+   * When running a content script with `browser.scripting.executeScript`,
+   * values returned from this function will be returned in the `executeScript`
+   * result as well. Otherwise returning a value does nothing.
    */
-  main(): void | Promise<void>;
+  main(): any | Promise<any>;
 }
 
 export type ContentScriptDefinition =
@@ -763,8 +771,12 @@ export interface BackgroundDefinition extends BackgroundEntrypointOptions {
 export interface UnlistedScriptDefinition extends BaseEntrypointOptions {
   /**
    * Main function executed when the unlisted script is ran.
+   *
+   * When running a content script with `browser.scripting.executeScript`,
+   * values returned from this function will be returned in the `executeScript`
+   * result as well. Otherwise returning a value does nothing.
    */
-  main(): void | Promise<void>;
+  main(): any | Promise<any>;
 }
 
 /**

src/virtual/content-script-isolated-world-entrypoint.ts

@@ -2,16 +2,23 @@ import definition from 'virtual:user-content-script-isolated-world-entrypoint';
 import { logger } from '../sandbox/utils/logger';
 import { ContentScriptContext } from 'wxt/client';
 
-(async () => {
+const result = (async () => {
   try {
     const { main, ...options } = definition;
     const ctx = new ContentScriptContext(import.meta.env.ENTRYPOINT, options);
 
-    await main(ctx);
+    return await main(ctx);
   } catch (err) {
     logger.error(
       `The content script "${import.meta.env.ENTRYPOINT}" crashed on startup!`,
       err,
     );
+    throw err;
   }
 })();
+
+// Return the main function's result to the background when executed via the
+// scripting API. Default export causes the IIFE to return a value.
+// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/scripting/executeScript#return_value
+// Tested on both Chrome and Firefox
+export default result;

src/virtual/content-script-main-world-entrypoint.ts

@@ -1,14 +1,21 @@
 import definition from 'virtual:user-content-script-main-world-entrypoint';
 import { logger } from '../sandbox/utils/logger';
 
-(async () => {
+const result = (async () => {
   try {
     const { main } = definition;
-    await main();
+    return await main();
   } catch (err) {
     logger.error(
       `The content script "${import.meta.env.ENTRYPOINT}" crashed on startup!`,
       err,
     );
+    throw err;
   }
 })();
+
+// Return the main function's result to the background when executed via the
+// scripting API. Default export causes the IIFE to return a value.
+// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/scripting/executeScript#return_value
+// Tested on both Chrome and Firefox
+export default result;

src/virtual/unlisted-script-entrypoint.ts

@@ -1,13 +1,20 @@
 import definition from 'virtual:user-unlisted-script-entrypoint';
 import { logger } from '../sandbox/utils/logger';
 
-(async () => {
+const result = (async () => {
   try {
-    await definition.main();
+    return await definition.main();
   } catch (err) {
     logger.error(
       `The unlisted script "${import.meta.env.ENTRYPOINT}" crashed on startup!`,
       err,
     );
+    throw err;
   }
 })();
+
+// Return the main function's result to the background when executed via the
+// scripting API. Default export causes the IIFE to return a value.
+// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/scripting/executeScript#return_value
+// Tested on both Chrome and Firefox
+export default result;