jestjs · hainenber · Oct 7, 2025 · Oct 7, 2025 · Oct 7, 2025 · Oct 7, 2025
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Fixes
 
 - `[jest-runtime]` Fix issue where user cannot utilize dynamic import despite specifying `--experimental-vm-modules` Node option ([#15842](https://github.com/jestjs/jest/pull/15842))
+- `[jest-config]` Fix issue where user cannot toggle `collectCoverage` at project level ([#15588](https://github.com/jestjs/jest/issues/15588))
 
 ## 30.2.0
 

diff --git a/e2e/__tests__/__snapshots__/showConfig.test.ts.snap b/e2e/__tests__/__snapshots__/showConfig.test.ts.snap
@@ -105,7 +105,6 @@ exports[`--showConfig outputs config info and exits 1`] = `
     "bail": 0,
     "changedFilesWithAncestor": false,
     "ci": true,
-    "collectCoverage": false,
     "collectCoverageFrom": [],
     "coverageDirectory": "<<REPLACED_ROOT_DIR>>/coverage",
     "coverageProvider": "babel",

diff --git a/packages/jest-config/src/ValidConfig.ts b/packages/jest-config/src/ValidConfig.ts
@@ -208,6 +208,7 @@ export const initialProjectOptions: Config.InitialProjectOptions = {
   cache: true,
   cacheDirectory: '/tmp/user/jest',
   clearMocks: false,
+  collectCoverage: false,
   collectCoverageFrom: ['src', '!public'],
   coverageDirectory: 'coverage',
   coveragePathIgnorePatterns: [NODE_MODULES_REGEXP],

diff --git a/packages/jest-config/src/index.ts b/packages/jest-config/src/index.ts
@@ -151,6 +151,7 @@ const groupOptions = (
     cache: options.cache,
     cacheDirectory: options.cacheDirectory,
     clearMocks: options.clearMocks,
+    collectCoverage: options.collectCoverage,
     collectCoverageFrom: options.collectCoverageFrom,
     coverageDirectory: options.coverageDirectory,
     coveragePathIgnorePatterns: options.coveragePathIgnorePatterns,

diff --git a/packages/jest-config/src/normalize.ts b/packages/jest-config/src/normalize.ts
@@ -554,6 +554,9 @@ export default async function normalize(
   if (!options.coverageDirectory) {
     options.coverageDirectory = path.resolve(options.rootDir, 'coverage');
   }
+  if (!Object.hasOwn(options, 'collectCoverage')) {
+    options.collectCoverage = undefined;
+  }
 
   setupBabelJest(options);
   // TODO: Type this properly

diff --git a/packages/jest-transform/src/__tests__/ScriptTransformer.test.ts b/packages/jest-transform/src/__tests__/ScriptTransformer.test.ts
@@ -314,6 +314,7 @@ describe('ScriptTransformer', () => {
     config = makeProjectConfig({
       cache: true,
       cacheDirectory: '/cache/',
+      collectCoverage: undefined,
       id: 'test',
       rootDir: '/',
       transformIgnorePatterns: ['/node_modules/'],

diff --git a/packages/jest-transform/src/__tests__/__snapshots__/ScriptTransformer.test.ts.snap b/packages/jest-transform/src/__tests__/__snapshots__/ScriptTransformer.test.ts.snap
@@ -26,6 +26,7 @@ exports[`ScriptTransformer in async mode, passes expected transform options to g
           "cache": true,
           "cacheDirectory": "/cache/",
           "clearMocks": false,
+          "collectCoverage": undefined,
           "collectCoverageFrom": Array [
             "src",
             "!public",
@@ -177,6 +178,7 @@ exports[`ScriptTransformer passes expected transform options to getCacheKey 1`]
           "cache": true,
           "cacheDirectory": "/cache/",
           "clearMocks": false,
+          "collectCoverage": undefined,
           "collectCoverageFrom": Array [
             "src",
             "!public",
@@ -302,6 +304,7 @@ exports[`ScriptTransformer passes expected transform options to getCacheKeyAsync
           "cache": true,
           "cacheDirectory": "/cache/",
           "clearMocks": false,
+          "collectCoverage": undefined,
           "collectCoverageFrom": Array [
             "src",
             "!public",

diff --git a/packages/jest-transform/src/__tests__/shouldInstrument.test.ts b/packages/jest-transform/src/__tests__/shouldInstrument.test.ts
@@ -18,7 +18,10 @@ describe('shouldInstrument', () => {
     }),
     changedFiles: undefined,
   };
-  const defaultConfig = makeProjectConfig({rootDir: '/'});
+  const defaultConfig = makeProjectConfig({
+    collectCoverage: undefined,
+    rootDir: '/',
+  });
   describe('should return true', () => {
     const testShouldInstrument = (
       filename = defaultFilename,

diff --git a/packages/jest-transform/src/shouldInstrument.ts b/packages/jest-transform/src/shouldInstrument.ts
@@ -36,7 +36,11 @@ export default function shouldInstrument(
   config: Config.ProjectConfig,
   loadedFilenames?: Array<string>,
 ): boolean {
-  if (!options.collectCoverage) {
+  // Do not instrument when `collectCoverage` is toggled off global or project-wide
+  if (
+    !options.collectCoverage ||
+    (typeof config.collectCoverage === 'boolean' && !config.collectCoverage)
+  ) {
     return false;
   }
 

diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
@@ -331,6 +331,7 @@ export type ProjectConfig = {
   cache: boolean;
   cacheDirectory: string;
   clearMocks: boolean;
+  collectCoverage?: boolean;
   collectCoverageFrom: Array<string>;
   coverageDirectory: string;
   coveragePathIgnorePatterns: Array<string>;

diff --git a/packages/test-utils/src/config.ts b/packages/test-utils/src/config.ts
@@ -75,6 +75,7 @@ const DEFAULT_PROJECT_CONFIG: Config.ProjectConfig = {
   cache: false,
   cacheDirectory: '/test_cache_dir/',
   clearMocks: false,
+  collectCoverage: undefined,
   collectCoverageFrom: ['src', '!public'],
   coverageDirectory: 'coverage',
   coveragePathIgnorePatterns: [],