Jest: [Bug] babel-jest throws if `only` in babel.config.js excludes current file

[kopax]

I am upgrading jest 23.6.0 to jest 24.0.0.

They have deprecated setupTestFrameworkScriptFile , see: https://jestjs.io/docs/en/configuration#setupfilesafterenv-array

We used to have in our package.json:

"setupTestFrameworkScriptFile": "<rootDir>/internals/testing/test-bundler.js",

We have tried to update to :

"setupFilesAfterEnv": ["<rootDir>/internals/testing/test-bundler.js"],

We now have the following error in our test npm run test:

FAIL  src/Table/tests/Tbody.test.js
● Test suite failed to run

TypeError: Cannot read property 'config' of null

  at Object.getCacheKey (node_modules/babel-jest/build/index.js:127:22)

This is how our test-bundler.js:

const Enzyme = require('enzyme');
const Adapter = require('enzyme-adapter-react-16');
Enzyme.configure({ adapter: new Adapter() });

It fails when doing:
const babelOptions = loadBabelConfig("/home/dka/workspace/github.com/bootstrap-styled/v4", "/home/dka/workspace/github.com/bootstrap-styled/v4/internals/testing/test-bundler.js");
babelOptions is null

This is happening in babel-jest package after upgrading from 23.6.0 to 24.0.0

It seems that setupFilesAfterEnv behave differently, does anybody know how to fix it, I see many breaking change on their changlog since our two version but none says how to fix this.

reproduction

git clone [email protected]:bootstrap-styled/v4.git
cd v4
git checkout dev-jest24
npm i 
npm test

There's also a detailled issue on stackoverflow

Travis build failure: https://travis-ci.org/bootstrap-styled/v4/jobs/486846842#L614

[SimenB]

Thanks for the reproduction! This is a completely separate issue from #7438. This fails due to the babel config having only in it:

  only: [
    'src',
    'styleguide',
  ],

That makes loadPartialConfig return null (which is not documented behavior, but maybe makes sense?). You can update transformIgnorePatterns to ignore the same files while waiting for a fix.

diff --git i/package.json w/package.json
index da61831a..b03f0ea1 100644
--- i/package.json
+++ w/package.json
@@ -167,6 +167,10 @@
       "node_modules",
       "src"
     ],
+    "transformIgnorePatterns": [
+        "/node_modules/",
+        "/internals/"
+    ],
     "testRegex": "tests/.*\\.test\\.js$",
     "testResultsProcessor": "jest-sonar-reporter"
   },

---

@loganfsmyth does it make sense for loadPartialConfig to return null rather than just empty configuration?

[SimenB]

I think this is a babel bug, no? If no babel config is found, this is the result:

PartialConfig {
  options:
   { filename: '/Users/simen/repos/ugh/hello.js',
     babelrc: false,
     configFile: false,
     passPerPreset: false,
     envName: 'development',
     cwd: '/Users/simen/repos/ugh',
     root: '/Users/simen/repos/ugh',
     plugins: [],
     presets: [] },
  babelignore: undefined,
  babelrc: undefined,
  config: undefined }

$ cat index.js
const { loadPartialConfig } = require("@babel/core");

const o = loadPartialConfig({ filename: require.resolve("./hello.js") });

console.log(o);
$ cat hello.js
$ node index.js
PartialConfig {
  options:
   { filename: '/Users/simen/repos/ugh/hello.js',
     babelrc: false,
     configFile: false,
     passPerPreset: false,
     envName: 'development',
     cwd: '/Users/simen/repos/ugh',
     root: '/Users/simen/repos/ugh',
     plugins: [],
     presets: [] },
  babelignore: undefined,
  babelrc: undefined,
  config: undefined }

[kopax]

@SimenB thanks, I have applied the temporary fix by adding into package.json under jest:

+  transformIgnorePatterns: [
+  '/node_modules/'
+  '/internals/'
+  ]

Thanks!

[SimenB]

Still a bug, in either Jest or Babel, so I'll reopen this to keep track of it 🙂

[loganfsmyth]

babel.transform() returns null if a file is ignored, and loadPartialConfig does the same because we stop processing the config ASAP to avoid doing extra work for ignored files.

[leMaik]

This also fails when the current test file is excluded with ignore in the .babelrc file.

[SimenB]

Yeah, we need to handle Babel saying "nope". I'll put together a PR

[SimenB]

Not sure how to handle code coverage. We currently do that by adding a babel plugin. Should we still do that even though a file is ignored by babel config?

[SimenB]

I think I'll just throw an error saying that you need to also ignore the file in transformIgnorePatterns if babel wants to ignore the file

[leMaik]

@SimenB Yes, a warning like that would have helped me. Thank you for the fast response :)

[SimenB]

PR: #7797