Only bundle the release build, and don't import src in tests (#13978)

* Only bundle the release build, and don't import `src` in tests

* Use file extension to signal skipping

* Remove unnecessary config change

* Fix imports

jest.config.js

@@ -1,4 +1,5 @@
 const supportsESM = parseInt(process.versions.node) >= 12;
+const isPublishBundle = process.env.IS_PUBLISH;
 
 module.exports = {
   collectCoverageFrom: [
@@ -23,6 +24,9 @@ module.exports = {
     "<rootDir>/build/",
     "<rootDir>/.history/", // local directory for VSCode Extension - https://marketplace.visualstudio.com/items?itemName=xyz.local-history
     "_browser\\.js",
+    // Some tests require internal files of bundled packages, which are not available
+    // in production builds. They are marked using the .skip-bundled.js extension.
+    ...(isPublishBundle ? ["\\.skip-bundled\\.js$"] : []),
   ],
   testEnvironment: "node",
   setupFilesAfterEnv: ["<rootDir>/test/testSetupFile.js"],