Fix multi-project untested coverage collection (#15358)

packages/jest-reporters/src/CoverageReporter.ts

@@ -113,18 +113,31 @@ export default class CoverageReporter extends BaseReporter {
 
     for (const context of testContexts) {
       const config = context.config;
-      if (
-        this._globalConfig.collectCoverageFrom &&
-        this._globalConfig.collectCoverageFrom.length > 0
-      ) {
+      const collectCoverageFromSets = [
+        this._globalConfig.collectCoverageFrom,
+        config.collectCoverageFrom,
+      ];
+      const seenFiles = new Set<string>();
+
+      for (const collectCoverageFrom of collectCoverageFromSets) {
+        if (!collectCoverageFrom || collectCoverageFrom.length === 0) {
+          continue;
+        }
+
         for (const filePath of context.hasteFS.matchFilesWithGlob(
-          this._globalConfig.collectCoverageFrom,
+          collectCoverageFrom,
           config.rootDir,
-        ))
+        )) {
+          if (seenFiles.has(filePath)) {
+            continue;
+          }
+
+          seenFiles.add(filePath);
           files.push({
             config,
             path: filePath,
           });
+        }
       }
     }
 

packages/jest-reporters/src/__tests__/CoverageReporter.test.js

@@ -15,18 +15,24 @@ jest
   .mock('istanbul-reports', () => ({
     ...jest.createMockFromModule('istanbul-reports'),
     create: jest.fn(() => ({execute: jest.fn()})),
+  }))
+  .mock('../CoverageWorker', () => ({
+    worker: jest.fn(),
   }));
 
 let libCoverage;
 let libSourceMaps;
 let CoverageReporter;
+let CoverageWorker;
 let istanbulReports;
 
 import * as path from 'path';
 import mock from 'mock-fs';
 
 beforeEach(() => {
+  jest.clearAllMocks();
   CoverageReporter = require('../CoverageReporter').default;
+  CoverageWorker = require('../CoverageWorker');
   libCoverage = require('istanbul-lib-coverage');
   libSourceMaps = require('istanbul-lib-source-maps');
   istanbulReports = require('istanbul-reports');
@@ -111,6 +117,8 @@ describe('onRunComplete', () => {
       }, {});
 
       return {
+        addFileCoverage: jest.fn(),
+        data: {},
         fileCoverageFor(path) {
           if (fileCoverage[path]) {
             return {
@@ -448,4 +456,88 @@ describe('onRunComplete', () => {
         expect(testReporter.getLastError()).toBeUndefined();
       });
   });
+
+  test('collects untested files from project config when running multiple projects', () => {
+    const projectConfig = {
+      collectCoverageFrom: ['src/**/*.js'],
+      rootDir: '/project-a',
+    };
+    const hasteFS = {
+      matchFilesWithGlob: jest
+        .fn()
+        .mockReturnValue(new Set(['/project-a/src/untested.js'])),
+    };
+    CoverageWorker.worker.mockResolvedValue(undefined);
+
+    const testReporter = new CoverageReporter(
+      {
+        collectCoverage: true,
+        collectCoverageFrom: [],
+        coverageReporters: [],
+        maxWorkers: 1,
+      },
+      {},
+    );
+
+    return testReporter
+      .onRunComplete(
+        new Set([{config: projectConfig, hasteFS}]),
+        mockAggResults,
+      )
+      .then(() => {
+        expect(hasteFS.matchFilesWithGlob).toHaveBeenCalledWith(
+          projectConfig.collectCoverageFrom,
+          projectConfig.rootDir,
+        );
+        expect(CoverageWorker.worker).toHaveBeenCalledWith(
+          expect.objectContaining({
+            config: projectConfig,
+            globalConfig: expect.objectContaining({collectCoverageFrom: []}),
+            path: '/project-a/src/untested.js',
+          }),
+        );
+        expect(testReporter.getLastError()).toBeUndefined();
+      });
+  });
+
+  test('deduplicates untested files matched by global and project coverage globs', () => {
+    const collectCoverageFrom = ['src/**/*.js'];
+    const projectConfig = {
+      collectCoverageFrom,
+      rootDir: '/project-a',
+    };
+    const hasteFS = {
+      matchFilesWithGlob: jest
+        .fn()
+        .mockReturnValue(new Set(['/project-a/src/untested.js'])),
+    };
+    CoverageWorker.worker.mockResolvedValue(undefined);
+
+    const testReporter = new CoverageReporter(
+      {
+        collectCoverage: true,
+        collectCoverageFrom,
+        coverageReporters: [],
+        maxWorkers: 1,
+      },
+      {},
+    );
+
+    return testReporter
+      .onRunComplete(
+        new Set([{config: projectConfig, hasteFS}]),
+        mockAggResults,
+      )
+      .then(() => {
+        expect(hasteFS.matchFilesWithGlob).toHaveBeenCalledTimes(2);
+        expect(CoverageWorker.worker).toHaveBeenCalledTimes(1);
+        expect(CoverageWorker.worker).toHaveBeenCalledWith(
+          expect.objectContaining({
+            config: projectConfig,
+            path: '/project-a/src/untested.js',
+          }),
+        );
+        expect(testReporter.getLastError()).toBeUndefined();
+      });
+  });
 });