fix: always resolve "jest-environment-jsdom" from jest-config (#7476)

Closes #7064

Author: aleclarson

CHANGELOG.md

@@ -42,6 +42,7 @@
 - `[jest-config]` Allow `bail` setting to be configured with a number allowing tests to abort after `n` of failures ([#7335](https://github.com/facebook/jest/pull/7335))
 - `[jest-config]` Allow % based configuration of `--max-workers` ([#7494](https://github.com/facebook/jest/pull/7494))
 - `[jest-runner]` Instantiate the test environment class with the current `testPath` ([#7442](https://github.com/facebook/jest/pull/7442))
+- `[jest-config]` Always resolve jest-environment-jsdom from jest-config ([#7476](https://github.com/facebook/jest/pull/7476))
 
 ### Fixes
 

e2e/__tests__/__snapshots__/show_config.test.js.snap

@@ -52,7 +52,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
       \\"setupFilesAfterEnv\\": [],
       \\"skipFilter\\": false,
       \\"snapshotSerializers\\": [],
-      \\"testEnvironment\\": \\"jest-environment-jsdom\\",
+      \\"testEnvironment\\": \\"<<REPLACED_JEST_PACKAGES_DIR>>/jest-environment-jsdom/build/index.js\\",
       \\"testEnvironmentOptions\\": {},
       \\"testLocationInResults\\": false,
       \\"testMatch\\": [

packages/jest-config/src/normalize.js

@@ -416,12 +416,10 @@ export default function normalize(options: InitialOptions, argv: Argv) {
     options = setupPreset(options, options.preset);
   }
 
-  if (options.testEnvironment) {
-    options.testEnvironment = getTestEnvironment({
-      rootDir: options.rootDir,
-      testEnvironment: options.testEnvironment,
-    });
-  }
+  options.testEnvironment = getTestEnvironment({
+    rootDir: options.rootDir,
+    testEnvironment: options.testEnvironment || 'jsdom',
+  });
 
   if (!options.roots && options.testPathDirs) {
     options.roots = options.testPathDirs;