Resolves the test sequencer even when not explicitly set (#8267)

* Fixes the test-sequencer resolution w/ pnp

* Update CHANGELOG.md

* Update normalize.ts

* Update normalize.ts

* Fixes snapshot

* Fix testSequencer value being overwritten by 'old style' of options.

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Fixes
 
+- `[@jest/config]` Normalize `testSequencer` to its absolute path ([#8267](https://github.com/facebook/jest/pull/8267))
 - `[@jest/console]` Print to stderr when calling `console.error`, `console.warn` or `console.assert` using the `jest-runtime` CLI ([#8261](https://github.com/facebook/jest/pull/8261))
 
 ### Chore & Maintenance

e2e/__tests__/__snapshots__/showConfig.test.ts.snap

@@ -117,7 +117,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
     "testFailureExitCode": 1,
     "testPathPattern": "",
     "testResultsProcessor": null,
-    "testSequencer": "@jest/test-sequencer",
+    "testSequencer": "<<REPLACED_JEST_PACKAGES_DIR>>/jest-test-sequencer/build/index.js",
     "updateSnapshot": "all",
     "useStderr": false,
     "verbose": null,

packages/jest-config/src/normalize.ts

@@ -589,17 +589,6 @@ export default function normalize(
             });
         }
         break;
-      case 'testSequencer':
-        {
-          const option = oldOptions[key];
-          value =
-            option &&
-            getSequencer(newOptions.resolver, {
-              filePath: option,
-              rootDir: options.rootDir,
-            });
-        }
-        break;
       case 'prettierPath':
         {
           // We only want this to throw if "prettierPath" is explicitly passed
@@ -883,6 +872,11 @@ export default function normalize(
     // ignored
   }
 
+  newOptions.testSequencer = getSequencer(newOptions.resolver, {
+    filePath: options.testSequencer || DEFAULT_CONFIG.testSequencer,
+    rootDir: options.rootDir,
+  });
+
   newOptions.nonFlagArgs = argv._;
   newOptions.testPathPattern = buildTestPathPattern(argv);
   newOptions.json = !!argv.json;