Skip to content

Commit

Permalink
Produce source maps when instrumenting code (jestjs#5739)
Browse files Browse the repository at this point in the history
  • Loading branch information
Matthew Preble committed Jan 24, 2020
1 parent 8607684 commit 52df3f7
Show file tree
Hide file tree
Showing 3 changed files with 143 additions and 27 deletions.
58 changes: 44 additions & 14 deletions packages/jest-transform/src/ScriptTransformer.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -191,8 +191,12 @@ export default class ScriptTransformer {
return transform;
}

private _instrumentFile(filename: Config.Path, content: string): string {
const result = babelTransform(content, {
private _instrumentFile(
filename: Config.Path,
input: TransformedSource,
canMapToInput: boolean,
): TransformedSource {
const result = babelTransform(input.code, {
auxiliaryCommentBefore: ' istanbul ignore next ',
babelrc: false,
caller: {
Expand All @@ -209,21 +213,28 @@ export default class ScriptTransformer {
// files outside `cwd` will not be instrumented
cwd: this._config.rootDir,
exclude: [],
// Needed for correct coverage as soon as we start storing a source map of the instrumented code
inputSourceMap: input.map,
useInlineSourceMaps: false,
},
],
],
/**
* Necessary to be able to map back to original source from the instrumented code
* the inline map is needed for debugging functionality
* and exposing it as a separate file is needed for e.g. mapping stack traces
* convenient to use 'both' here and avoid extracting the source map
*
* Prior behavior of emitting no map when we can't map back to original source is preserved
*/
sourceMaps: canMapToInput ? 'both' : false,
});

if (result) {
const {code} = result;

if (code) {
return code;
}
if (result && result.code) {
return {code: result.code, map: result.map};
}

return content;
return {code: input.code};
}

private _getRealPath(filepath: Config.Path): Config.Path {
Expand Down Expand Up @@ -312,17 +323,36 @@ export default class ScriptTransformer {
}
}

// Apply instrumentation to the code if necessary, keeping the instrumented code and new map
let map = transformed.map;
if (!transformWillInstrument && instrument) {
code = this._instrumentFile(filename, transformed.code);
/**
* We can map the original source code to the instrumented code ONLY if
* - the process of transforming the code produced a source map e.g. ts-jest
* - we did not transform the source code
*
* Otherwise we cannot make any statements about how the instrumented code
* corresponds to the original code, and should NOT emit any source maps
*
*/
const shouldEmitSourceMaps = (!!transform && !!map) || !transform;
const instrumented = this._instrumentFile(
filename,
transformed,
shouldEmitSourceMaps,
);
code = instrumented.code;

if (instrumented.map) {
map = instrumented.map;
}
} else {
code = transformed.code;
}

if (transformed.map) {
if (map) {
const sourceMapContent =
typeof transformed.map === 'string'
? transformed.map
: JSON.stringify(transformed.map);
typeof map === 'string' ? map : JSON.stringify(map);
writeCacheFile(sourceMapPath, sourceMapContent);
} else {
sourceMapPath = null;
Expand Down
12 changes: 8 additions & 4 deletions packages/jest-transform/src/__tests__/__snapshots__/script_transformer.test.js.snap
View file
Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,7 @@ exports[`ScriptTransformer transforms a file properly 1`] = `
/* istanbul ignore next */
function cov_25u22311x4() {
var path = "/fruits/banana.js";
var hash = "4be0f6184160be573fc43f7c2a5877c28b7ce249";
var hash = "3f8e915bed83285455a8a16aa04dc0cf5242d755";
var global = new Function("return this")();
var gcv = "__coverage__";
var coverageData = {
Expand All @@ -102,8 +102,9 @@ function cov_25u22311x4() {
},
f: {},
b: {},
inputSourceMap: null,
_coverageSchema: "1a1c01bbd47fc00a2c39e90264f33305004495a9",
hash: "4be0f6184160be573fc43f7c2a5877c28b7ce249"
hash: "3f8e915bed83285455a8a16aa04dc0cf5242d755"
};
var coverage = global[gcv] || (global[gcv] = {});
Expand All @@ -122,13 +123,14 @@ function cov_25u22311x4() {
cov_25u22311x4().s[0]++;
module.exports = "banana";
//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImJhbmFuYS5qcyJdLCJuYW1lcyI6WyJtb2R1bGUiLCJleHBvcnRzIl0sIm1hcHBpbmdzIjoiOzs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7OztBQUFBQSxNQUFNLENBQUNDLE9BQVAsR0FBaUIsUUFBakIiLCJzb3VyY2VzQ29udGVudCI6WyJtb2R1bGUuZXhwb3J0cyA9IFwiYmFuYW5hXCI7Il19
`;

exports[`ScriptTransformer transforms a file properly 2`] = `
/* istanbul ignore next */
function cov_23yvu8etmu() {
var path = "/fruits/kiwi.js";
var hash = "7705dd5fcfbc884dcea7062944cfb8cc5d141d1a";
var hash = "8b5afd38d79008f13ebc229b89ef82b12ee9447a";
var global = new Function("return this")();
var gcv = "__coverage__";
var coverageData = {
Expand Down Expand Up @@ -190,8 +192,9 @@ function cov_23yvu8etmu() {
"0": 0
},
b: {},
inputSourceMap: null,
_coverageSchema: "1a1c01bbd47fc00a2c39e90264f33305004495a9",
hash: "7705dd5fcfbc884dcea7062944cfb8cc5d141d1a"
hash: "8b5afd38d79008f13ebc229b89ef82b12ee9447a"
};
var coverage = global[gcv] || (global[gcv] = {});
Expand All @@ -216,6 +219,7 @@ module.exports = () => {
cov_23yvu8etmu().s[1]++;
return "kiwi";
};
//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImtpd2kuanMiXSwibmFtZXMiOlsibW9kdWxlIiwiZXhwb3J0cyJdLCJtYXBwaW5ncyI6Ijs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7QUFBQUEsTUFBTSxDQUFDQyxPQUFQLEdBQWlCLE1BQU07QUFBQTtBQUFBO0FBQUE7QUFBQTtBQUFNLENBQTdCIiwic291cmNlc0NvbnRlbnQiOlsibW9kdWxlLmV4cG9ydHMgPSAoKSA9PiBcImtpd2lcIjsiXX0=
`;

exports[`ScriptTransformer uses multiple preprocessors 1`] = `
Expand Down
100 changes: 91 additions & 9 deletions packages/jest-transform/src/__tests__/script_transformer.test.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -400,9 +400,7 @@ describe('ScriptTransformer', () => {

const result = scriptTransformer.transform(
'/fruits/banana.js',
makeGlobalConfig({
collectCoverage: true,
}),
makeGlobalConfig(),
);
expect(result.sourceMapPath).toEqual(expect.any(String));
const mapStr = JSON.stringify(map);
Expand Down Expand Up @@ -433,9 +431,7 @@ describe('ScriptTransformer', () => {

const result = scriptTransformer.transform(
'/fruits/banana.js',
makeGlobalConfig({
collectCoverage: true,
}),
makeGlobalConfig(),
);
expect(result.sourceMapPath).toEqual(expect.any(String));
expect(writeFileAtomic.sync).toBeCalledTimes(2);
Expand Down Expand Up @@ -504,9 +500,7 @@ describe('ScriptTransformer', () => {

const result = scriptTransformer.transform(
'/fruits/banana.js',
makeGlobalConfig({
collectCoverage: true,
}),
makeGlobalConfig(),
);
expect(result.sourceMapPath).toEqual(expect.any(String));
expect(writeFileAtomic.sync).toBeCalledTimes(2);
Expand Down Expand Up @@ -541,6 +535,94 @@ describe('ScriptTransformer', () => {
expect(writeFileAtomic.sync).toHaveBeenCalledTimes(1);
});

it('should write a source map for the instrumented file when transformed', () => {
config = {
...config,
transform: [['^.+\\.js$', 'preprocessor-with-sourcemaps']],
};
const scriptTransformer = new ScriptTransformer(config);

const map = {
mappings: ';AAAA',
version: 3,
};

// A map from the original source to the instrumented output
/* eslint-disable sort-keys */
const instrumentedCodeMap = {
version: 3,
sources: ['banana.js'],
names: ['content'],
mappings: ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA,OAAO',
sourcesContent: ['content'],
};
/* eslint-enable sort-keys */

require('preprocessor-with-sourcemaps').process.mockReturnValue({
code: 'content',
map,
});

const result = scriptTransformer.transform(
'/fruits/banana.js',
makeGlobalConfig({
collectCoverage: true,
}),
);
expect(result.sourceMapPath).toEqual(expect.any(String));
expect(writeFileAtomic.sync).toBeCalledTimes(2);
expect(writeFileAtomic.sync).toBeCalledWith(
result.sourceMapPath,
JSON.stringify(instrumentedCodeMap),
{
encoding: 'utf8',
},
);

// Inline source map allows debugging of original source when running instrumented code
expect(result.code).toContain('//# sourceMappingURL');
});

it('should write a source map for the instrumented file when not transformed', () => {
const scriptTransformer = new ScriptTransformer(config);

// A map from the original source to the instrumented output
/* eslint-disable sort-keys */
const instrumentedCodeMap = {
version: 3,
sources: ['banana.js'],
names: ['module', 'exports'],
mappings:
';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA,MAAM,CAACC,OAAP,GAAiB,QAAjB',
sourcesContent: ['module.exports = "banana";'],
};
/* eslint-enable sort-keys */

require('preprocessor-with-sourcemaps').process.mockReturnValue({
code: 'content',
map: null,
});

const result = scriptTransformer.transform(
'/fruits/banana.js',
makeGlobalConfig({
collectCoverage: true,
}),
);
expect(result.sourceMapPath).toEqual(expect.any(String));
expect(writeFileAtomic.sync).toBeCalledTimes(2);
expect(writeFileAtomic.sync).toBeCalledWith(
result.sourceMapPath,
JSON.stringify(instrumentedCodeMap),
{
encoding: 'utf8',
},
);

// Inline source map allows debugging of original source when running instrumented code
expect(result.code).toContain('//# sourceMappingURL');
});

it('passes expected transform options to getCacheKey', () => {
config = {...config, transform: [['^.+\\.js$', 'test_preprocessor']]};
const scriptTransformer = new ScriptTransformer(config);
Expand Down

0 comments on commit 52df3f7

Please sign in to comment.