feat(jest-core): allow using Summary Reporter as stand-alone reporter

CHANGELOG.md

@@ -18,6 +18,7 @@
 - `[jest-core]` Pass project config to `globalSetup`/`globalTeardown` function as second argument ([#12440](https://github.com/facebook/jest/pull/12440))
 - `[jest-core]` Stabilize test runners with event emitters ([#12641](https://github.com/facebook/jest/pull/12641))
 - `[jest-core, jest-watcher]` [**BREAKING**] Move `TestWatcher` class to `jest-watcher` package ([#12652](https://github.com/facebook/jest/pull/12652))
+- `[jest-core]` Allow using Summary Reporter as stand-alone reporter ([#12687](https://github.com/facebook/jest/pull/12687))
 - `[jest-environment-jsdom]` [**BREAKING**] Upgrade jsdom to 19.0.0 ([#12290](https://github.com/facebook/jest/pull/12290))
 - `[jest-environment-jsdom]` [**BREAKING**] Add default `browser` condition to `exportConditions` for `jsdom` environment ([#11924](https://github.com/facebook/jest/pull/11924))
 - `[jest-environment-jsdom]` [**BREAKING**] Pass global config to Jest environment constructor for `jsdom` environment ([#12461](https://github.com/facebook/jest/pull/12461))

docs/Configuration.md

@@ -856,6 +856,16 @@ If included in the list, the built-in GitHub Actions Reporter will annotate chan
 }
 ```
 
+#### Summary Reporter
+
+Summary reporter prints out summary of all tests. It is a part of default reporter, hence it will be enabled if `'default'` is included in the list. For instance, you might want to use it as stand-alone reporter instead of the default one, or together with [Silent Reporter](https://github.com/rickhanlonii/jest-silent-reporter):
+
+```json
+{
+  "reporters": ["jest-silent-reporter", "summary"]
+}
+```
+
 #### Custom Reporters
 
 :::tip

e2e/__tests__/customReporters.test.ts

@@ -142,7 +142,6 @@ describe('Custom Reporters Integration', () => {
       'package.json': JSON.stringify({
         jest: {
           reporters: ['default', '<rootDir>/reporter.js'],
-          testEnvironment: 'node',
         },
       }),
       'reporter.js': `
@@ -167,7 +166,6 @@ describe('Custom Reporters Integration', () => {
         'package.json': JSON.stringify({
           jest: {
             reporters: ['default', '<rootDir>/reporter.mjs'],
-            testEnvironment: 'node',
           },
         }),
         'reporter.mjs': `

jest.config.ci.mjs

@@ -20,5 +20,6 @@ export default {
       'jest-silent-reporter',
       {showPaths: true, showWarnings: true, useDots: true},
     ],
+    'summary',
   ],
 };

packages/jest-config/src/normalize.ts

@@ -433,7 +433,7 @@ const normalizeReporters = (options: Config.InitialOptionsWithRootDir) => {
       normalizedReporterConfig[0],
     );
 
-    if (!['default', 'github-actions'].includes(reporterPath)) {
+    if (!['default', 'github-actions', 'summary'].includes(reporterPath)) {
       const reporter = Resolver.findNodeModule(reporterPath, {
         basedir: options.rootDir,
       });

packages/jest-core/src/TestScheduler.ts

@@ -55,8 +55,6 @@ type TestRunnerConstructor = new (
 
 export type TestSchedulerContext = ReporterContext & TestRunnerContext;
 
-type ReporterMap = Record<string, Record<string, unknown>>;
-
 export async function createTestScheduler(
   globalConfig: Config.GlobalConfig,
   context: TestSchedulerContext,
@@ -329,77 +327,59 @@ class TestScheduler {
   }
 
   async _setupReporters() {
-    const {collectCoverage, notify, reporters} = this._globalConfig;
+    const {collectCoverage: coverage, notify, verbose} = this._globalConfig;
+    const reporters = this._globalConfig.reporters || [['default', {}]];
+    let summary = false;
+
+    for (const [reporter, options] of reporters) {
+      switch (reporter) {
+        case 'default':
+          summary = true;
+          verbose
+            ? this.addReporter(new VerboseReporter(this._globalConfig))
+            : this.addReporter(new DefaultReporter(this._globalConfig));
+          break;
+        case 'github-actions':
+          GITHUB_ACTIONS && this.addReporter(new GitHubActionsReporter());
+          break;
+        case 'summary':
+          summary = true;
+          break;
+        default:
+          await this._addCustomReporter(reporter, options);
+      }
+    }
 
     if (notify) {
       this.addReporter(new NotifyReporter(this._globalConfig, this._context));
     }
 
-    if (!reporters) {
-      this._setupDefaultReporters(collectCoverage);
-      return;
-    }
-
-    let reporterMap: ReporterMap = {};
-
-    reporters.forEach(reporter => {
-      reporterMap = Object.assign(reporterMap, {
-        [reporter[0]]: reporter[1],
-      });
-    });
-
-    const reporterNames = Object.keys(reporterMap);
-
-    const isDefault = reporterNames.includes('default');
-    const isGitHubActions =
-      GITHUB_ACTIONS && reporterNames.includes('github-actions');
-
-    if (isDefault) {
-      this._setupDefaultReporters(collectCoverage);
-    }
-
-    if (isGitHubActions) {
-      this.addReporter(new GitHubActionsReporter());
-    }
-
-    if (!isDefault && collectCoverage) {
+    if (coverage) {
       this.addReporter(new CoverageReporter(this._globalConfig, this._context));
     }
 
-    if (reporterNames.length) {
-      await this._addCustomReporters(reporterMap);
-    }
-  }
-
-  private _setupDefaultReporters(collectCoverage: boolean) {
-    this.addReporter(
-      this._globalConfig.verbose
-        ? new VerboseReporter(this._globalConfig)
-        : new DefaultReporter(this._globalConfig),
-    );
-
-    if (collectCoverage) {
-      this.addReporter(new CoverageReporter(this._globalConfig, this._context));
+    if (summary) {
+      this.addReporter(new SummaryReporter(this._globalConfig));
     }
-
-    this.addReporter(new SummaryReporter(this._globalConfig));
   }
 
-  private async _addCustomReporters(reporters: ReporterMap) {
-    for (const path in reporters) {
-      if (['default', 'github-actions'].includes(path)) continue;
+  private async _addCustomReporter(
+    reporter: string,
+    options: Record<string, unknown>,
+  ) {
+    try {
+      const Reporter: ReporterConstructor = await requireOrImportModule(
+        reporter,
+      );
 
-      try {
-        const Reporter: ReporterConstructor = await requireOrImportModule(path);
-        this.addReporter(
-          new Reporter(this._globalConfig, reporters[path], this._context),
-        );
-      } catch (error: any) {
-        error.message = `An error occurred while adding the reporter at path "${chalk.bold(
-          path,
-        )}".\n${error.message}`;
-        throw error;
-      }
+      this.addReporter(
+        new Reporter(this._globalConfig, options, this._context),
+      );
+    } catch (error: any) {
+      error.message = `An error occurred while adding the reporter at path "${chalk.bold(
+        reporter,
+      )}".\n${error instanceof Error ? error.message : ''}`;
+      throw error;
     }
   }