feat!: ESM background support (#398)

BREAKING CHANGE: The build output has changed slightly. This isn't a huge deal, and no steps are required for users unless you're doing something weird with the output files after a build. Before: ``` .output/ <target>/ chunks/ popup-<hash>.js popup.html ``` After: ``` .output/ <target>/ popup.html popup.js ``` This applies for all HTML files, not just the popup.
wxt-dev · Feb 2, 2024 · eca3029 · eca3029
1 parent 41fa320
commit eca3029
Show file tree

Hide file tree

Showing 8 changed files with 340 additions and 81 deletions.
diff --git a/demo/src/entrypoints/background.ts b/demo/src/entrypoints/background.ts
@@ -1,37 +1,41 @@
 import messages from 'public/_locales/en/messages.json';
 
-export default defineBackground(() => {
-  console.log(browser.runtime.id);
-  logId();
-  console.log({
-    browser: import.meta.env.BROWSER,
-    chrome: import.meta.env.CHROME,
-    firefox: import.meta.env.FIREFOX,
-    manifestVersion: import.meta.env.MANIFEST_VERSION,
-    messages,
-  });
+export default defineBackground({
+  // type: 'module',
 
-  // @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');
+  main() {
+    console.log(browser.runtime.id);
+    logId();
+    console.log({
+      browser: import.meta.env.BROWSER,
+      chrome: import.meta.env.CHROME,
+      firefox: import.meta.env.FIREFOX,
+      manifestVersion: import.meta.env.MANIFEST_VERSION,
+      messages,
+    });
 
-  // @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');
+    // @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');
 
-  console.log('WXT MODE:', {
-    MODE: import.meta.env.MODE,
-    DEV: import.meta.env.DEV,
-    PROD: import.meta.env.PROD,
-  });
+    // @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');
 
-  storage.setItem('session:startTime', Date.now());
+    console.log('WXT MODE:', {
+      MODE: import.meta.env.MODE,
+      DEV: import.meta.env.DEV,
+      PROD: import.meta.env.PROD,
+    });
+
+    storage.setItem('session:startTime', Date.now());
+  },
 });
diff --git a/e2e/tests/output-structure.test.ts b/e2e/tests/output-structure.test.ts
@@ -227,4 +227,169 @@ describe('Output Directory Structure', () => {
       true,
     );
   });
+
+  it('should generate ESM background script when type=module', async () => {
+    const project = new TestProject();
+    project.addFile(
+      'utils/log.ts',
+      `export function logHello(name: string) {
+        console.log(\`Hello \${name}!\`);
+      }`,
+    );
+    project.addFile(
+      'entrypoints/background.ts',
+      `export default defineBackground({
+        type: "module",
+        main() {
+          logHello("background");
+        },
+      })`,
+    );
+    project.addFile(
+      'entrypoints/popup/index.html',
+      `<html>
+        <head>
+          <script type="module" src="./main.ts"></script>
+        </head>
+      </html>`,
+    );
+    project.addFile('entrypoints/popup/main.ts', `logHello('popup')`);
+
+    await project.build({
+      experimental: {
+        // Simplify the build output for comparison
+        includeBrowserPolyfill: false,
+      },
+      vite: () => ({
+        build: {
+          // Make output for snapshot readible
+          minify: false,
+        },
+      }),
+    });
+
+    expect(await project.serializeFile('.output/chrome-mv3/background.js'))
+      .toMatchInlineSnapshot(`
+      ".output/chrome-mv3/background.js
+      ----------------------------------------
+      import { l as logHello } from "./chunks/log-bezs0tt4.js";
+      function defineBackground(arg) {
+        if (typeof arg === "function")
+          return { main: arg };
+        return arg;
+      }
+      const definition = defineBackground({
+        type: "module",
+        main() {
+          logHello("background");
+        }
+      });
+      chrome;
+      function print(method, ...args) {
+        return;
+      }
+      var logger = {
+        debug: (...args) => print(console.debug, ...args),
+        log: (...args) => print(console.log, ...args),
+        warn: (...args) => print(console.warn, ...args),
+        error: (...args) => print(console.error, ...args)
+      };
+      try {
+        const res = definition.main();
+        if (res instanceof Promise) {
+          console.warn(
+            "The background's main() function return a promise, but it must be synchonous"
+          );
+        }
+      } catch (err) {
+        logger.error("The background crashed on startup!");
+        throw err;
+      }
+      "
+    `);
+  });
+
+  it('should generate IIFE background script when type=undefined', async () => {
+    const project = new TestProject();
+    project.addFile(
+      'utils/log.ts',
+      `export function logHello(name: string) {
+          console.log(\`Hello \${name}!\`);
+        }`,
+    );
+    project.addFile(
+      'entrypoints/background.ts',
+      `export default defineBackground({
+          main() {
+            logHello("background");
+          },
+        })`,
+    );
+    project.addFile(
+      'entrypoints/popup/index.html',
+      `<html>
+          <head>
+            <script type="module" src="./main.ts"></script>
+          </head>
+        </html>`,
+    );
+    project.addFile('entrypoints/popup/main.ts', `logHello('popup')`);
+
+    await project.build({
+      experimental: {
+        // Simplify the build output for comparison
+        includeBrowserPolyfill: false,
+      },
+      vite: () => ({
+        build: {
+          // Make output for snapshot readible
+          minify: false,
+        },
+      }),
+    });
+
+    expect(await project.serializeFile('.output/chrome-mv3/background.js'))
+      .toMatchInlineSnapshot(`
+        ".output/chrome-mv3/background.js
+        ----------------------------------------
+        (function() {
+          "use strict";
+          function defineBackground(arg) {
+            if (typeof arg === "function")
+              return { main: arg };
+            return arg;
+          }
+          function logHello(name) {
+            console.log(\`Hello \${name}!\`);
+          }
+          const definition = defineBackground({
+            main() {
+              logHello("background");
+            }
+          });
+          chrome;
+          function print(method, ...args) {
+            return;
+          }
+          var logger = {
+            debug: (...args) => print(console.debug, ...args),
+            log: (...args) => print(console.log, ...args),
+            warn: (...args) => print(console.warn, ...args),
+            error: (...args) => print(console.error, ...args)
+          };
+          try {
+            const res = definition.main();
+            if (res instanceof Promise) {
+              console.warn(
+                "The background's main() function return a promise, but it must be synchonous"
+              );
+            }
+          } catch (err) {
+            logger.error("The background crashed on startup!");
+            throw err;
+          }
+        })();
+        "
+      `);
+  });
 });
diff --git a/src/core/builders/vite/index.ts b/src/core/builders/vite/index.ts
@@ -75,23 +75,7 @@ export async function createViteBuilder(
    * Return the basic config for building an entrypoint in [lib mode](https://vitejs.dev/guide/build.html#library-mode).
    */
   const getLibModeConfig = (entrypoint: Entrypoint): vite.InlineConfig => {
-    let virtualEntrypointType: VirtualEntrypointType | undefined;
-    switch (entrypoint.type) {
-      case 'background':
-      case 'unlisted-script':
-        virtualEntrypointType = entrypoint.type;
-        break;
-      case 'content-script':
-        virtualEntrypointType =
-          entrypoint.options.world === 'MAIN'
-            ? 'content-script-main-world'
-            : 'content-script-isolated-world';
-        break;
-    }
-    const entry = virtualEntrypointType
-      ? `virtual:wxt-${virtualEntrypointType}?${entrypoint.inputPath}`
-      : entrypoint.inputPath;
-
+    const entry = getRollupEntry(entrypoint);
     const plugins: NonNullable<vite.UserConfig['plugins']> = [
       wxtPlugins.entrypointGroupGlobals(entrypoint),
     ];
@@ -157,14 +141,16 @@ export async function createViteBuilder(
       build: {
         rollupOptions: {
           input: entrypoints.reduce<Record<string, string>>((input, entry) => {
-            input[entry.name] = entry.inputPath;
+            input[entry.name] = getRollupEntry(entry);
             return input;
           }, {}),
           output: {
             // Include a hash to prevent conflicts
             chunkFileNames: 'chunks/[name]-[hash].js',
-            // Include a hash to prevent conflicts
-            entryFileNames: 'chunks/[name]-[hash].js',
+            // Place JS entrypoints in main directory without a hash. (popup.html & popup.js are
+            // next to each other). The unique entrypoint name requirement prevents conflicts with
+            // scripts of the same name
+            entryFileNames: '[name].js',
             // We can't control the "name", so we need a hash to prevent conflicts
             assetFileNames: 'assets/[name]-[hash].[ext]',
           },
@@ -263,3 +249,26 @@ function getBuildOutputChunks(
   if (Array.isArray(result)) return result.flatMap(({ output }) => output);
   return result.output;
 }
+
+/**
+ * Returns the input module ID (virtual or real file) for an entrypoint. The returned string should
+ * be passed as an input to rollup.
+ */
+function getRollupEntry(entrypoint: Entrypoint): string {
+  let virtualEntrypointType: VirtualEntrypointType | undefined;
+  switch (entrypoint.type) {
+    case 'background':
+    case 'unlisted-script':
+      virtualEntrypointType = entrypoint.type;
+      break;
+    case 'content-script':
+      virtualEntrypointType =
+        entrypoint.options.world === 'MAIN'
+          ? 'content-script-main-world'
+          : 'content-script-isolated-world';
+      break;
+  }
+  return virtualEntrypointType
+    ? `virtual:wxt-${virtualEntrypointType}?${entrypoint.inputPath}`
+    : entrypoint.inputPath;
+}
diff --git a/src/core/create-server.ts b/src/core/create-server.ts
@@ -8,7 +8,6 @@ import {
 } from '~/types';
 import {
   getEntrypointBundlePath,
-  getEntrypointOutputFile,
   resolvePerBrowserOption,
 } from '~/core/utils/entrypoints';
 import {
@@ -197,15 +196,6 @@ function createFileReloader(options: {
           .join(', ')}`,
       );
 
-      const rebuiltNames = changes.rebuildGroups
-        .flat()
-        .map((entry) => {
-          return pc.cyan(
-            relative(config.outDir, getEntrypointOutputFile(entry, '')),
-          );
-        })
-        .join(pc.dim(', '));
-
       // Rebuild entrypoints on change
       const allEntrypoints = await findEntrypoints(config);
       const { output: newOutput } = await rebuild(
@@ -221,15 +211,24 @@ function createFileReloader(options: {
       switch (changes.type) {
         case 'extension-reload':
           server.reloadExtension();
+          consola.success(`Reloaded extension`);
           break;
         case 'html-reload':
-          reloadHtmlPages(changes.rebuildGroups, server, config);
+          const { reloadedNames } = reloadHtmlPages(
+            changes.rebuildGroups,
+            server,
+            config,
+          );
+          consola.success(`Reloaded: ${getFilenameList(reloadedNames)}`);
           break;
         case 'content-script-reload':
           reloadContentScripts(changes.changedSteps, config, server);
+          const rebuiltNames = changes.rebuildGroups
+            .flat()
+            .map((entry) => entry.name);
+          consola.success(`Reloaded: ${getFilenameList(rebuiltNames)}`);
           break;
       }
-      consola.success(`Reloaded: ${rebuiltNames}`);
     });
   };
 }
@@ -279,9 +278,26 @@ function reloadHtmlPages(
   groups: EntrypointGroup[],
   server: WxtDevServer,
   config: InternalConfig,
-) {
-  groups.flat().forEach((entry) => {
+): { reloadedNames: string[] } {
+  // groups might contain other files like background/content scripts, and we only care about the HTMl pages
+  const htmlEntries = groups
+    .flat()
+    .filter((entry) => entry.inputPath.endsWith('.html'));
+
+  htmlEntries.forEach((entry) => {
     const path = getEntrypointBundlePath(entry, config.outDir, '.html');
     server.reloadPage(path);
   });
+
+  return {
+    reloadedNames: htmlEntries.map((entry) => entry.name),
+  };
+}
+
+function getFilenameList(names: string[]): string {
+  return names
+    .map((name) => {
+      return pc.cyan(name);
+    })
+    .join(pc.dim(', '));
 }