Removing the mapCoverage condition on reading inlineSourceMaps. (#5177)

* * Removed usage of mapCoverage on reading inline sourcemaps.
* Removed usage of instrument check before saving file into cache.
* Passing sourceMaps only for files on which the coverage was obtained
* Updated the changelog

* Removed usage of mapCoverage from codebase

* * Maintaining internal mapCoverage, map only for files which are instrumented by us
* Feat: Return sourcemap from babel-jest

* Adding back retainLines

* * Removed the mapCoverage from docs
* Updated the integration testcases

* Remove mapCoverage from code base and add deprecation warning

* Get sourcemaps only for the files covered in testcases

* Updated the condition in babel-jest to prevent breaking changes for the existing users

* Added some tests for babel-jest

Author: Aftabnack

CHANGELOG.md

@@ -8,6 +8,10 @@
 
 ### Features
 * `[docs]` Add MongoDB guide ([#5571](https://github.com/facebook/jest/pull/5571))
+* `[jest-runtime]` Deprecate mapCoverage option.
+  ([#5177](https://github.com/facebook/jest/pull/5177))
+* `[babel-jest]` Add option to return sourcemap from the transformer separately
+  from source. ([#5177](https://github.com/facebook/jest/pull/5177))
 
 ## jest 22.3.0
 
@@ -1597,4 +1601,4 @@ See https://facebook.github.io/jest/blog/2016/12/15/2016-in-jest.html
 
 ## <=0.4.0
 
-* See commit history for changes in previous versions of jest.
+* See commit history for changes in previous versions of jest.

TestUtils.js

@@ -32,7 +32,6 @@ const DEFAULT_GLOBAL_CONFIG: GlobalConfig = {
   lastCommit: false,
   listTests: false,
   logHeapUsage: false,
-  mapCoverage: false,
   maxWorkers: 2,
   noSCM: null,
   noStackTrace: false,

docs/Configuration.md

@@ -313,34 +313,6 @@ Default: `undefined`
 This option allows the use of a custom global teardown module which exports an
 async function that is triggered once after all test suites.
 
-### `mapCoverage` [boolean]
-
-##### available in Jest **20.0.0+**
-
-Default: `false`
-
-If you have [transformers](#transform-object-string-string) configured that emit
-source maps, Jest will use them to try and map code coverage against the
-original source code when writing [reports](#coveragereporters-array-string) and
-checking [thresholds](#coveragethreshold-object). This is done on a best-effort
-basis as some compile-to-JavaScript languages may provide more accurate source
-maps than others. This can also be resource-intensive. If Jest is taking a long
-time to calculate coverage at the end of a test run, try setting this option to
-`false`.
-
-Both inline source maps and source maps returned directly from a transformer are
-supported. Source map URLs are not supported because Jest may not be able to
-locate them. To return source maps from a transformer, the `process` function
-can return an object like the following. The `map` property may either be the
-source map object, or the source map object as a string.
-
-```js
-return {
-  code: 'the code',
-  map: 'the source map',
-};
-```
-
 ### `moduleFileExtensions` [array<string>]
 
 Default: `["js", "json", "jsx", "node"]`

integration-tests/__tests__/__snapshots__/coverage_transform_instrumented.test.js.snap

@@ -0,0 +1,78 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`code coverage for transform instrumented code 1`] = `
+Object {
+  "covered.js": Object {
+    "_coverageSchema": "332fd63041d2c1bcb487cc26dd0d5f7d97098a6c",
+    "b": Object {},
+    "branchMap": Object {},
+    "f": Object {
+      "0": 1,
+    },
+    "fnMap": Object {
+      "0": Object {
+        "decl": Object {
+          "end": Object {
+            "column": 36,
+            "line": 9,
+          },
+          "start": Object {
+            "column": 26,
+            "line": 9,
+          },
+        },
+        "line": 9,
+        "loc": Object {
+          "end": Object {
+            "column": 1,
+            "line": 12,
+          },
+          "start": Object {
+            "column": 58,
+            "line": 9,
+          },
+        },
+        "name": "doES6Stuff",
+      },
+    },
+    "path": "covered.js",
+    "s": Object {
+      "0": 1,
+      "1": 1,
+      "2": 1,
+    },
+    "statementMap": Object {
+      "0": Object {
+        "end": Object {
+          "column": 2,
+          "line": 12,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 9,
+        },
+      },
+      "1": Object {
+        "end": Object {
+          "column": 41,
+          "line": 10,
+        },
+        "start": Object {
+          "column": 34,
+          "line": 10,
+        },
+      },
+      "2": Object {
+        "end": Object {
+          "column": 33,
+          "line": 11,
+        },
+        "start": Object {
+          "column": 2,
+          "line": 11,
+        },
+      },
+    },
+  },
+}
+`;

integration-tests/__tests__/__snapshots__/show_config.test.js.snap

@@ -75,7 +75,6 @@ exports[`--showConfig outputs config info and exits 1`] = `
     \\"globalSetup\\": null,
     \\"globalTeardown\\": null,
     \\"listTests\\": false,
-    \\"mapCoverage\\": false,
     \\"maxWorkers\\": \\"[maxWorkers]\\",
     \\"noStackTrace\\": false,
     \\"nonFlagArgs\\": [],

integration-tests/__tests__/coverage_remapping.test.js

@@ -23,7 +23,7 @@ beforeAll(() => {
 
 it('maps code coverage against original source', () => {
   run('yarn', dir);
-  const result = runJest(dir, ['--coverage', '--mapCoverage', '--no-cache']);
+  const result = runJest(dir, ['--coverage', '--no-cache']);
 
   expect(result.status).toBe(0);
 

integration-tests/__tests__/coverage_transform_instrumented.test.js

@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+'use strict';
+
+const {readFileSync} = require('fs');
+const path = require('path');
+const {cleanup, run} = require('../Utils');
+const runJest = require('../runJest');
+
+const dir = path.resolve(__dirname, '../coverage-transform-instrumented');
+const coverageDir = path.join(dir, 'coverage');
+
+beforeAll(() => {
+  cleanup(coverageDir);
+});
+
+it('code coverage for transform instrumented code', () => {
+  run('yarn', dir);
+  const result = runJest(dir, ['--coverage', '--no-cache']);
+
+  expect(result.status).toBe(0);
+
+  const coverageMapFile = path.join(coverageDir, 'coverage-final.json');
+  const coverageMap = JSON.parse(readFileSync(coverageMapFile, 'utf-8'));
+
+  // reduce absolute paths embedded in the coverage map to just filenames
+  Object.keys(coverageMap).forEach(filename => {
+    coverageMap[filename].path = path.basename(coverageMap[filename].path);
+    delete coverageMap[filename].hash;
+    coverageMap[path.basename(filename)] = coverageMap[filename];
+    delete coverageMap[filename];
+  });
+  expect(coverageMap).toMatchSnapshot();
+});

integration-tests/__tests__/stack_trace_source_maps.test.js

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+'use strict';
+
+const path = require('path');
+const {run} = require('../Utils');
+const runJest = require('../runJest');
+
+it('processes stack traces and code frames with source maps', () => {
+  const dir = path.resolve(__dirname, '../stack-trace-source-maps');
+  run('yarn', dir);
+  const {stderr} = runJest(dir, ['--no-cache']);
+  expect(stderr).toMatch('> 14 |   (() => expect(false).toBe(true))();');
+  expect(stderr).toMatch(`at __tests__/fails.ts:14:24
+      at Object.<anonymous> (__tests__/fails.ts:14:35)`);
+});

integration-tests/coverage-transform-instrumented/Preprocessor.js

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const jestPreset = require('babel-preset-jest');
+const babelTransform = require('babel-core').transform;
+const babelIstanbulPlugin = require('babel-plugin-istanbul').default;
+
+const options = {
+  presets: ['env', jestPreset],
+  retainLines: true,
+  sourceMaps: 'inline',
+};
+
+module.exports = {
+  canInstrument: true,
+  process(src, filename, config, transformOptions) {
+    options.filename = filename;
+    if (transformOptions && transformOptions.instrument) {
+      options.auxiliaryCommentBefore = ' istanbul ignore next ';
+      options.plugins = [
+        [
+          babelIstanbulPlugin,
+          {
+            cwd: config.rootDir,
+            exclude: [],
+          },
+        ],
+      ];
+    }
+
+    const transformResult = babelTransform(src, options);
+
+    if (!transformResult) {
+      return src;
+    }
+
+    return transformResult.code;
+  },
+};

integration-tests/coverage-transform-instrumented/__tests__/covered-test.js

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const doES6Stuff = require('../covered.js');
+
+it('works correctly', () => {
+  const someObj = {someNumber: 10, this: 'is irrelevant'};
+  expect(doES6Stuff(someObj, 2)).toBe(20);
+});