Make swc jest configurable without a flag

.changeset/polite-chefs-boil.md

@@ -0,0 +1,6 @@
+---
+'modular-scripts': minor
+---
+
+Use of swc Jest for testing can now be configured through modular configuration
+file

docs/configuration.md

@@ -40,6 +40,7 @@ module.exports = {
   externalAllowList: ['**'],
   publicUrl: '',
   generateSourceMap: true,
+  swcJest: false,
 };
 ```
 
@@ -69,8 +70,8 @@ esm.sh. Only applies to ESM Views.
 Packages that should be bundled and not fetched from a CDN. We recommend
 allowing all packages to be handled by the CDN, except for particular cases
 where they would not work correctly. See
-[known-limitations](./esm-views/known-limitations.md). Defaults to none. Only
-applies to ESM Views.
+[customize bundle strategy](./esm-views/customize-bundle-strategy.md). Defaults
+to none. Only applies to ESM Views.
 
 ### externalAllowList
 
@@ -103,6 +104,16 @@ Should build process generate a source map - can be disabled for performance
 reasons. Source maps are resource heavy and can cause out of memory issue for
 large source files.
 
+### swcJest
+
+**Type**: `boolean`
+
+**Default**: `false`
+
+Use Rust based SWC Jest runner instead of ts-jest & babel for performance
+improvements. Can be breaking for certain tests and configurations. Cannot be
+configured per package, must be configured at root.
+
 ## `package.json#modular`
 
 _NOTE: This property is created automatically and is described here for

package.json

@@ -14,7 +14,7 @@
     "lint:fix": "yarn lint --fix",
     "create-modular-react-app": "ts-node packages/create-modular-react-app/src/cli.ts",
     "modular": "ts-node packages/modular-scripts/src/cli.ts",
-    "test": "cross-env NODE_OPTIONS=--max_old_space_size=5120 yarn modular test --swc --runInBand --env=node",
+    "test": "cross-env NODE_OPTIONS=--max_old_space_size=5120 yarn modular test --runInBand --env=node",
     "build": "yarn workspace @modular-scripts/workspace-resolver build && yarn workspace create-modular-react-app build && yarn workspace modular-scripts build && yarn modular build @modular-scripts/remote-view && yarn prepare:remote-view",
     "prepare": "is-ci || husky install",
     "prepare:remote-view:copy": "cp -R dist/modular-scripts-remote-view packages/remote-view/dist",
@@ -106,7 +106,8 @@
     "coverageProvider": "v8"
   },
   "modular": {
-    "type": "root"
+    "type": "root",
+    "swcJest": true
   },
   "lint-staged": {
     "*.{js,ts,tsx,mjs,md,yml,json}": "yarn prettier --write -l",

packages/modular-scripts/src/test/index.ts

@@ -13,6 +13,7 @@ import {
   computeRegexesFromPackageNames,
   partitionPackages,
 } from '../utils/unobtrusiveModular';
+import { getConfig } from '../utils/config';
 
 export interface TestOptions {
   bypass: boolean;
@@ -91,10 +92,18 @@ async function test(options: TestOptions, packages?: string[]): Promise<void> {
   // pass in jest configuration
   const { createJestConfig } = await import('./config');
 
+  const configuredSwc = swc ? swc : getConfig('swcJest', getModularRoot());
+  console.error(
+    'CONFIGURED SWC: ',
+    JSON.stringify(getConfig('swcJest', getModularRoot())),
+  );
+
+  if (configuredSwc) console.error('USING SWC');
+
   cleanArgv.push(
     '--config',
     generateJestConfig(
-      createJestConfig({ reporters, testResultsProcessor }, swc),
+      createJestConfig({ reporters, testResultsProcessor }, configuredSwc),
     ),
   );
 

packages/modular-scripts/src/utils/config.ts

@@ -28,6 +28,7 @@ interface Config {
   externalAllowList: string[];
   publicUrl: string;
   generateSourceMap: boolean;
+  swcJest: boolean;
 }
 
 type ConfigDefs = {
@@ -77,6 +78,13 @@ const defs: ConfigDefs = {
         ? process.env.GENERATE_SOURCEMAP === 'true'
         : undefined,
   },
+  swcJest: {
+    default: false,
+    override:
+      process.env.SWC_JEST === 'true' || process.env.SWC_JEST === 'false'
+        ? process.env.SWC_JEST === 'true'
+        : undefined,
+  },
 };
 
 const explorer = cosmiconfigSync('modular', { searchPlaces });