Fix workers with old targets (#6579)

packages/core/core/src/public/Environment.js

@@ -224,6 +224,10 @@ export default class Environment implements IEnvironment {
  }
 
  let matchedBrowsers = browserslist(browsers);
+ if (matchedBrowsers.length === 0) {
+ return false;
+ }
+
  let minBrowsers = getExcludedBrowsers(minVersions);
  let withoutMinBrowsers = browserslist([...browsers, ...minBrowsers]);
  return matchedBrowsers.length === withoutMinBrowsers.length;

packages/core/integration-tests/test/integration/worker-dynamic/index.js

@@ -1,4 +1,2 @@
 let worker = new Worker(new URL('worker.js', import.meta.url), {type: 'module'});
-export default new Promise(resolve => {
- worker.addEventListener('message', resolve);
-});
+worker.addEventListener('message', output);

packages/core/integration-tests/test/javascript.js

@@ -798,13 +798,48 @@ describe('javascript', function() {
  assertBundles(b, [
  {
  name: 'index.js',
+ assets: ['index.js', 'bundle-url.js', 'get-worker-url.js'],
+ },
+ {
  assets: [
- 'index.js',
+ 'worker.js',
  'bundle-url.js',
- 'get-worker-url.js',
- 'esmodule-helpers.js',
+ 'cacheLoader.js',
+ 'js-loader.js',
  ],
  },
+ {
+ assets: ['async.js', 'esmodule-helpers.js'],
+ },
+ ]);
+
+ let res = await new Promise(resolve => {
+ run(b, {
+ output: resolve,
+ });
+ });
+ assert.deepEqual(res, {default: 42});
+ });
+
+ it('should support bundling workers with dynamic import with legacy browser targets', async function() {
+ let b = await bundle(
+ path.join(__dirname, '/integration/worker-dynamic/index.js'),
+ {
+ defaultTargetOptions: {
+ outputFormat: 'esmodule',
+ shouldScopeHoist: true,
+ engines: {
+ browsers: 'IE 11',
+ },
+ },
+ },
+ );
+
+ assertBundles(b, [
+ {
+ name: 'index.js',
+ assets: ['index.js', 'bundle-url.js', 'get-worker-url.js'],
+ },
  {
  assets: [
  'worker.js',
@@ -814,12 +849,16 @@ describe('javascript', function() {
  ],
  },
  {
- assets: ['async.js', 'esmodule-helpers.js'],
+ assets: ['async.js'],
  },
  ]);
 
- let res = await run(b);
- assert.deepEqual(await res.default, {default: 42});
+ let res = await new Promise(resolve => {
+ run(b, {
+ output: resolve,
+ });
+ });
+ assert.deepEqual(res, {default: 42});
  });
 
  it('should support bundling workers of type module', async function() {

packages/transformers/js/core/src/lib.rs

@@ -272,6 +272,7 @@ pub fn transform(config: Config) -> Result<TransformResult, std::io::Error> {
  let decls = collect_decls(&module);
 
  let mut preset_env_config = swc_ecma_preset_env::Config::default();
+ preset_env_config.dynamic_import = true;
  if let Some(versions) = targets_to_versions(&config.targets) {
  preset_env_config.targets = Some(Targets::Versions(versions));
  preset_env_config.shipped_proposals = true;