diff --git a/e2e/__tests__/onlyChanged.test.ts b/e2e/__tests__/onlyChanged.test.ts
index 2e160e4a4bb1..947a11d50ddc 100644
--- a/e2e/__tests__/onlyChanged.test.ts
+++ b/e2e/__tests__/onlyChanged.test.ts
@@ -165,7 +165,7 @@ test('report test coverage of source on test file change under only changed file
   `,
   });
 
-  const {stdout} = runJest(DIR, ['-o']);
+  const {stdout} = runJest(DIR, ['--only-changed']);
 
   expect(stdout).toMatch('a.js');
 });
diff --git a/packages/jest-core/src/SearchSource.ts b/packages/jest-core/src/SearchSource.ts
index 9efa210e6a7d..194664594c16 100644
--- a/packages/jest-core/src/SearchSource.ts
+++ b/packages/jest-core/src/SearchSource.ts
@@ -54,9 +54,7 @@ const toTests = (context: Context, tests: Array<Config.Path>) =>
 const hasSCM = (changedFilesInfo: ChangedFiles) => {
   const {repos} = changedFilesInfo;
   // no SCM (git/hg/...) is found in any of the roots.
-  const noSCM = (Object.keys(repos) as Array<
-    keyof ChangedFiles['repos']
-  >).every(scm => repos[scm].size === 0);
+  const noSCM = Object.values(repos).every(scm => scm.size === 0);
   return !noSCM;
 };
 
@@ -352,7 +350,7 @@ export default class SearchSource {
     );
     const relatedSourcesSet = new Set<string>();
     changedFiles.forEach(filePath => {
-      const isTestFile = this.isTestFilePath.bind(this)(filePath);
+      const isTestFile = this.isTestFilePath(filePath);
       if (isTestFile) {
         const sourcePaths = dependencyResolver.resolve(filePath, {
           skipNodeResolution: this._context.config.skipNodeResolution,
diff --git a/packages/jest-core/src/TestScheduler.ts b/packages/jest-core/src/TestScheduler.ts
index 6b6f7810528f..bf455a2e05c1 100644
--- a/packages/jest-core/src/TestScheduler.ts
+++ b/packages/jest-core/src/TestScheduler.ts
@@ -181,9 +181,9 @@ export default class TestScheduler {
       if (!testRunners[config.runner]) {
         const Runner: typeof TestRunner = require(config.runner);
         testRunners[config.runner] = new Runner(this._globalConfig, {
-          changedFiles: this._context && this._context.changedFiles,
-          sourcesRelatedToTestsInChangedFiles:
-            this._context && this._context.sourcesRelatedToTestsInChangedFiles,
+          changedFiles: this._context?.changedFiles,
+          sourcesRelatedToTestsInChangedFiles: this._context
+            ?.sourcesRelatedToTestsInChangedFiles,
         });
       }
     });
@@ -275,9 +275,9 @@ export default class TestScheduler {
     if (!isDefault && collectCoverage) {
       this.addReporter(
         new CoverageReporter(this._globalConfig, {
-          changedFiles: this._context && this._context.changedFiles,
-          sourcesRelatedToTestsInChangedFiles:
-            this._context && this._context.sourcesRelatedToTestsInChangedFiles,
+          changedFiles: this._context?.changedFiles,
+          sourcesRelatedToTestsInChangedFiles: this._context
+            ?.sourcesRelatedToTestsInChangedFiles,
         }),
       );
     }
@@ -307,9 +307,9 @@ export default class TestScheduler {
     if (collectCoverage) {
       this.addReporter(
         new CoverageReporter(this._globalConfig, {
-          changedFiles: this._context && this._context.changedFiles,
-          sourcesRelatedToTestsInChangedFiles:
-            this._context && this._context.sourcesRelatedToTestsInChangedFiles,
+          changedFiles: this._context?.changedFiles,
+          sourcesRelatedToTestsInChangedFiles: this._context
+            ?.sourcesRelatedToTestsInChangedFiles,
         }),
       );
     }
diff --git a/packages/jest-core/src/__tests__/SearchSource.test.ts b/packages/jest-core/src/__tests__/SearchSource.test.ts
index 9bf4c5344ec9..307e2c2f68b0 100644
--- a/packages/jest-core/src/__tests__/SearchSource.test.ts
+++ b/packages/jest-core/src/__tests__/SearchSource.test.ts
@@ -533,30 +533,18 @@ describe('SearchSource', () => {
   });
 
   describe('findRelatedSourcesFromTestsInChangedFiles', () => {
-    const rootDir = path.join(
+    const rootDir = path.resolve(
       __dirname,
-      '..',
-      '..',
-      '..',
-      'jest-runtime',
-      'src',
-      '__tests__',
-      'test_root',
+      '../../../jest-runtime/src/__tests__/test_root',
     );
 
     beforeEach(done => {
       const {options: config} = normalize(
         {
           haste: {
-            hasteImplModulePath: path.join(
+            hasteImplModulePath: path.resolve(
               __dirname,
-              '..',
-              '..',
-              '..',
-              'jest-haste-map',
-              'src',
-              '__tests__',
-              'haste_impl.js',
+              '../../../jest-haste-map/src/__tests__/haste_impl.js',
             ),
             providesModuleNodeModules: [],
           },
diff --git a/packages/jest-core/src/runJest.ts b/packages/jest-core/src/runJest.ts
index 1f0ef43b002b..787762903f8e 100644
--- a/packages/jest-core/src/runJest.ts
+++ b/packages/jest-core/src/runJest.ts
@@ -243,8 +243,8 @@ export default async function runJest({
 
   if (changedFilesPromise) {
     const changedFilesInfo = await changedFilesPromise;
-    testSchedulerContext.changedFiles = changedFilesInfo.changedFiles;
-    if (testSchedulerContext.changedFiles) {
+    if (changedFilesInfo.changedFiles) {
+      testSchedulerContext.changedFiles = changedFilesInfo.changedFiles;
       const sourcesRelatedToTestsInChangedFilesArray = contexts
         .map(context => {
           const searchSource = new SearchSource(context);
@@ -253,7 +253,7 @@ export default async function runJest({
           );
           return relatedSourceFromTestsInChangedFiles;
         })
-        .reduce((total, paths) => [...total, ...paths], []);
+        .reduce((total, paths) => total.concat(paths), []);
       testSchedulerContext.sourcesRelatedToTestsInChangedFiles = new Set(
         sourcesRelatedToTestsInChangedFilesArray,
       );
diff --git a/packages/jest-reporters/src/coverage_worker.ts b/packages/jest-reporters/src/coverage_worker.ts
index 567a8b98064e..d1894b97574c 100644
--- a/packages/jest-reporters/src/coverage_worker.ts
+++ b/packages/jest-reporters/src/coverage_worker.ts
@@ -40,9 +40,8 @@ export function worker({
     path,
     globalConfig,
     config,
-    options && options.changedFiles && new Set(options.changedFiles),
-    options &&
-      options.sourcesRelatedToTestsInChangedFiles &&
+    options?.changedFiles && new Set(options.changedFiles),
+    options?.sourcesRelatedToTestsInChangedFiles &&
       new Set(options.sourcesRelatedToTestsInChangedFiles),
   );
 }
diff --git a/packages/jest-runner/src/runTest.ts b/packages/jest-runner/src/runTest.ts
index 7c957493db51..d9a64a874155 100644
--- a/packages/jest-runner/src/runTest.ts
+++ b/packages/jest-runner/src/runTest.ts
@@ -147,13 +147,13 @@ async function runTestInternal(
   setGlobal(environment.global, 'console', testConsole);
 
   const runtime = new Runtime(config, environment, resolver, cacheFS, {
-    changedFiles: context && context.changedFiles,
+    changedFiles: context?.changedFiles,
     collectCoverage: globalConfig.collectCoverage,
     collectCoverageFrom: globalConfig.collectCoverageFrom,
     collectCoverageOnlyFrom: globalConfig.collectCoverageOnlyFrom,
     coverageProvider: globalConfig.coverageProvider,
     sourcesRelatedToTestsInChangedFiles:
-      context && context.sourcesRelatedToTestsInChangedFiles,
+      context?.sourcesRelatedToTestsInChangedFiles,
   });
 
   const start = Date.now();