Jest: Coverage hasn't worked since last major semver update

[dsifford]

Hello,

I've been trying to troubleshoot this on my own off and on for the last few days, but unfortunately I haven't been able to figure out what's going on. Issue #433 seems to be the closest thing to what I have going on, but none of the suggestions there helped.

Before the last major semver update, everything was working totally fine. Now, when I run jest with the same configs as before I get this.

64 tests passed (64 total in 16 test suites, run time 2.022s)
----------|----------|----------|----------|----------|----------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
----------|----------|----------|----------|----------|----------------|
----------|----------|----------|----------|----------|----------------|
All files |      100 |      100 |      100 |      100 |                |
----------|----------|----------|----------|----------|----------------|

For some reason, no tests are making it to the results table and, although coverage report is being generated, it's completely blank.

Here's my configs:

"jest": {
    "scriptPreprocessor": "jestPreprocessor.js",
    "testFileExtensions": [
      "ts",
      "tsx",
      "js"
    ],
    "moduleFileExtensions": [
      "js",
      "ts",
      "tsx",
      "json"
    ],
    "unmockedModulePathPatterns": [
      "react",
      "react-dom",
      "react-addons-test-utils",
      "fbjs",
      "enzyme",
      "sinon",
      "lib/js/utils/Constants",
      "lib/js/utils/Mocks"
    ],
    "verbose": true,
    "collectCoverage": true,
    "coverageDirectory": "tmp/coverage"
  },

It looks like a week or so ago collectCoverageFrom has been added to master, but that hasn't been released yet, so that's not really an option for now.

Here's the repo: https://github.com/dsifford/academic-bloggers-toolkit

Happy to answer any questions you might have. Thanks in advance for your work on this!

[aaronabramov]

hey @dsifford
thanks for reporting the issue!
i was able to find the problem. The new version of Istanbul uses babel to instrument the file, and basically this condition (https://github.com/facebook/jest/blob/429b2d1947cc427d01c33bddeae1378221a2a4f5/packages/jest-runtime/src/transform.js#L254) always returns false because of the .tsx file extension.

all make a fix for it on monday!

[dsifford]

@dmitriiabramov Wow, that's great to hear! Thanks so much again for your work on this!

[calclavia]

I'm getting the same issue. Looking forward to the fix!

[aaronabramov]

https://github.com/facebook/jest/pull/1430

[dsifford]

@dmitriiabramov Thanks again for the quick fix with this.

Does Jest have pre-release or nightly branches that I can pull with these changes? If not, any idea when the next update will be pushed through?

[aaronabramov]

we're going to release the next version in about two weeks or so.
@cpojer are you going to push anything to npm this week?

[cpojer]

I'm more or less continuously pushing a test tag this week. You can try npm install --save-dev jest@test to try it out. It's your own risk though, we are currently making many awesome changes but some of them might break (please report it though if it is a real bug!).

I published @dmitriiabramov's fix a minute ago, so please feel free to try it out. It's [email protected] or jest@test should work too.

[dsifford]

Awesome, sounds good. Thanks again so much!

[dsifford]

Not sure if you guys are aware, but the issue is persisting with jest@test. Didn't seem to make any change; even after flushing the cache.

Still no coverage being rendered. Happy to answer any specific questions either of you may have.

[aaronabramov]

@dsifford the bug was actually in jest-runtime not jest itself.
so you'll have to do something like rm -rf node_modules/*jest* and then npm i jest@test --save-dev

jest tried it on academic-bloggers-toolkit

[aaronabramov]

also now you can add something like this to your jest config

"jest": {
    "collectCoverageFrom": ["src/**/*.{js,ts,tsx}", "!**/{vendor,__tests__}/**"]
}

and this will also collect coverage for all files that are not tested but match this set of globs

[dsifford]

@dmitriiabramov Ah, ok sorry about the confusion.

Thanks for the clarification. Got it working now.

Also: collectCoverageFrom = 🔥 👍 👍

[calclavia]

I tried using collectCoverageFrom, after putting that in the config,I received:

ERROR: TypeError: Cannot read property 'instrument' of undefined

"jest": {
    "verbose": true,
    "coverageDirectory": "coverage",
    "automock": false,
    "scriptPreprocessor": "<rootDir>/jestProcessor.js",
    "collectCoverageFrom": ["src/**/*.{js,ts,tsx}", "!**/{vendor,__tests__}/**"]
  }

[aaronabramov]

@calclavia is there any stack trace? does it happen after/before or during the test run?

[calclavia]

It happens during the test run. I'll try to come up with a stack trace soon.

[jseminck]

I have the same issue.

I use a custom preprocessor (because jest fails when using CSS modules). When removing that custom preprocessor, then it seems to pick up the code without a problem. Could it be related to that? My preprocessor is pretty much this one:
https://github.com/justinsisley/Jest-CSS-Modules/blob/master/index.js

Stacktrace:

              Failed to collect coverage from /Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/src/components/Links/LinksPage.js
              ERROR: TypeError: Cannot read property 'instrument' of undefined
              STACK: TypeError: Cannot read property 'instrument' of undefined
    at Object.process (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/babel-jest/build/index.js:37:30)
    at Object.process (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/tools/jestPreprocessor.js:9:20)
    at transformSource (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest-runtime/build/transform.js:293:27)
    at transformSource (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest-runtime/build/index.js:91:38)
    at module.exports (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest/node_modules/jest-cli/build/generateEmptyCoverage.js:22:12)
    at /Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest/node_modules/jest-cli/build/reporters/CoverageReporter.js:87:13
    at Set.forEach (native)
    at CoverageReporter._addUntestedFiles (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest/node_modules/jest-cli/build/reporters/CoverageReporter.js:82:13)
    at CoverageReporter.onRunComplete (/Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest/node_modules/jest-cli/build/reporters/CoverageReporter.js:56:10)
    at /Users/joachimseminck/Projects/jseminck-be/jseminck-be-main/node_modules/jest/node_modules/jest-cli/build/TestRunner.js:437:14

[aaronabramov]

that should be fixed by https://github.com/facebook/jest/pull/1482

[jseminck]

Thanks. I'll try to test it today. I ended up throwing the preprocessor away in favour of another method. :)