config#collectCoverageFrom (#1349)

Author: boujeepossum

integration_tests/__tests__/__snapshots__/coverage_report-test.js.snap

@@ -0,0 +1,22 @@
+exports[`test collects coverage only from specified files 1`] = `
+"Using <<REPLACED>>, jasmine2
+----------|----------|----------|----------|----------|----------------|
+File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
+----------|----------|----------|----------|----------|----------------|
+All files |      100 |      100 |      100 |      100 |                |
+ setup.js |      100 |      100 |      100 |      100 |                |
+----------|----------|----------|----------|----------|----------------|
+"
+`;
+
+exports[`test outputs coverage report 1`] = `
+"Using <<REPLACED>>, jasmine2
+---------------|----------|----------|----------|----------|----------------|
+File           |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
+---------------|----------|----------|----------|----------|----------------|
+All files      |      100 |      100 |      100 |      100 |                |
+ other-file.js |      100 |      100 |      100 |      100 |                |
+ sum.js        |      100 |      100 |      100 |      100 |                |
+---------------|----------|----------|----------|----------|----------------|
+"
+`;

integration_tests/__tests__/coverage_report-test.js

@@ -9,25 +9,29 @@
  */
 'use strict';
 
+const {stripJestVersion} = require('../utils');
 const runJest = require('../runJest');
 const fs = require('fs');
 const path = require('path');
 
-describe('Coverage Report', () => {
-  it('outputs coverage report', () => {
-    const result = runJest('coverage_report', ['--coverage']);
-    const stdout = result.stdout.toString();
+it('outputs coverage report', () => {
+  const {stdout, status} = runJest('coverage_report', ['--coverage']);
+  const coverageDir = path.resolve(__dirname, '../coverage_report/coverage');
 
-    const coverageDir = path.resolve(__dirname, '../coverage_report/coverage');
-    expect(stdout).toMatch(/All files.*100.*100.*100.*100/);
-    expect(stdout).not.toMatch(/^.+__tests__.+\|.+\|.+\|.+\|/gm);
-    expect(stdout).not.toMatch(/^.+__mocks__.+\|.+\|.+\|.+\|/gm);
+  // should be no `setup.file` in the coverage report. It's ignored
+  expect(stripJestVersion(stdout)).toMatchSnapshot();
 
-    // Make sure `coveragePathIgnorePatterns` works
-    expect(stdout).not.toMatch('setup.js');
+  expect(() => fs.accessSync(coverageDir, fs.F_OK)).not.toThrow();
+  expect(status).toBe(0);
+});
+
+it('collects coverage only from specified files', () => {
+  const {stdout} = runJest('coverage_report', [
+    '--coverage',
+    '--collectCoverageFrom', // overwrites the one in package.json
+    'setup.js',
+  ]);
 
-    // this will throw if the coverage directory is not there
-    fs.accessSync(coverageDir, fs.F_OK);
-    expect(result.status).toBe(0);
-  });
+  // Coverage report should only have `setup.js` coverage info
+  expect(stripJestVersion(stdout)).toMatchSnapshot();
 });

integration_tests/__tests__/transform-test.js

@@ -10,13 +10,10 @@
 
 jest.unmock('../runJest');
 
-const {linkJestPackage, run} = require('../utils');
+const {linkJestPackage, run, stripJestVersion} = require('../utils');
 const path = require('path');
 const runJest = require('../runJest');
 
-const stripJestVersion = stdout =>
-  stdout.replace(/Jest CLI v\d{1,2}\.\d{1,2}\.\d{1,2}/, '<<REPLACED>>');
-
 describe('babel-jest', () => {
   const dir = path.resolve(__dirname, '..', 'transform/babel-jest');
 

integration_tests/coverage_report/other-file.js

@@ -0,0 +1,10 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+'use strict';
+
+module.exports = {a: 5};

integration_tests/coverage_report/package.json

@@ -1,9 +1,8 @@
 {
   "jest": {
-    "testEnvironment": "node",
-    "coveragePathIgnorePatterns": [
-      "<rootDir>/setup.js",
-      "packages\/jest"
+    "collectCoverageFrom": [
+      "*.js",
+      "!setup.js"
     ],
     "setupFiles": [
       "<rootDir>/setup.js"

integration_tests/coverage_report/sum.js

@@ -8,6 +8,7 @@
 'use strict';
 
 require('./sum_dependency.js');
+require('./other-file');
 
 module.exports = function(a, b) {
   return a + b;

integration_tests/transform/custom-instrumenting-preprocessor/src/index.js

@@ -8,4 +8,6 @@
 
 'use strict';
 
+require('./some-other-file');
+
 module.exports = {a: 1};

integration_tests/transform/custom-instrumenting-preprocessor/src/some-other-file.js

@@ -0,0 +1,11 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
+module.exports = {a: 1};

integration_tests/utils.js

@@ -46,8 +46,12 @@ const fileExists = filePath => {
   }
 };
 
+const stripJestVersion = stdout =>
+  stdout.replace(/Jest CLI v\d{1,2}\.\d{1,2}\.\d{1,2}/, '<<REPLACED>>');
+
 module.exports = {
   fileExists,
   linkJestPackage,
   run,
+  stripJestVersion,
 };

packages/jest-cli/src/cli/args.js

@@ -60,6 +60,13 @@ const options = {
     ),
     type: 'boolean',
   },
+  collectCoverageFrom: {
+    description: wrap(
+      'relative to <rootDir> glob pattern matching the files that coverage ' +
+      'info needs to be collected from.',
+    ),
+    type: 'string',
+  },
   maxWorkers: {
     alias: 'w',
     description: wrap(