fix: do not run global hooks if there are no tests

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - `[jest-cli]` Break dependency cycle when using Jest programmatically ([#7707](https://github.com/facebook/jest/pull/7707))
 - `[jest-config]` Extract setupFilesAfterEnv from preset ([#7724](https://github.com/facebook/jest/pull/7724))
+- `[jest-cli]` Do not execute any `globalSetup` or `globalTeardown` if there are no tests to execute ([#7745](https://github.com/facebook/jest/pull/7745))
 
 ### Chore & Maintenance
 

e2e/__tests__/globalSetup.test.js

@@ -103,3 +103,22 @@ test('should not call a globalSetup of a project if there are no tests to run fr
   expect(fs.existsSync(project1DIR)).toBe(true);
   expect(fs.existsSync(project2DIR)).toBe(false);
 });
+
+test('should not call any globalSetup if there are no tests to run', () => {
+  const configPath = path.resolve(
+    __dirname,
+    '../global-setup/projects.jest.config.js',
+  );
+
+  const result = runWithJson('global-setup', [
+    `--config=${configPath}`,
+    // onlyChanged ensures there are no tests to run
+    '--onlyChanged',
+  ]);
+
+  expect(result.status).toBe(0);
+
+  expect(fs.existsSync(DIR)).toBe(false);
+  expect(fs.existsSync(project1DIR)).toBe(false);
+  expect(fs.existsSync(project2DIR)).toBe(false);
+});

packages/jest-cli/src/runJest.js

@@ -217,7 +217,9 @@ export default (async function runJest({
     globalConfig = failedTestsCache.updateConfig(globalConfig);
   }
 
-  if (!allTests.length) {
+  const hasTests = allTests.length > 0;
+
+  if (!hasTests) {
     const noTestsFoundMessage = getNoTestsFoundMessage(
       testRunData,
       globalConfig,
@@ -250,7 +252,9 @@ export default (async function runJest({
     collectHandles = collectNodeHandles();
   }
 
-  await runGlobalHook({allTests, globalConfig, moduleName: 'globalSetup'});
+  if (hasTests) {
+    await runGlobalHook({allTests, globalConfig, moduleName: 'globalSetup'});
+  }
 
   const results = await new TestScheduler(
     globalConfig,
@@ -262,11 +266,9 @@ export default (async function runJest({
 
   sequencer.cacheResults(allTests, results);
 
-  await runGlobalHook({
-    allTests,
-    globalConfig,
-    moduleName: 'globalTeardown',
-  });
+  if (hasTests) {
+    await runGlobalHook({allTests, globalConfig, moduleName: 'globalTeardown'});
+  }
 
   return processResults(results, {
     collectHandles,

packages/jest-cli/src/watch.js

@@ -17,6 +17,7 @@ import chalk from 'chalk';
 import getChangedFilesPromise from './getChangedFilesPromise';
 import exit from 'exit';
 import HasteMap from 'jest-haste-map';
+import {formatExecError} from 'jest-message-util';
 import isValidPath from './lib/is_valid_path';
 import {isInteractive, specialChars} from 'jest-util';
 import {print as preRunMessagePrint} from './preRunMessage';
@@ -280,7 +281,10 @@ export default function watch(
       // continuous watch mode execution. We need to reprint them to the
       // terminal and give just a little bit of extra space so they fit below
       // `preRunMessagePrint` message nicely.
-      console.error('\n\n' + chalk.red(error)),
+      console.error(
+        '\n\n' +
+          formatExecError(error, contexts[0].config, {noStackTrace: false}),
+      ),
     );
   };