Retain posix paths in Jest config

[Timer]

Aims to resolve #1417 and #1498.

[gaearon]

This wouldn't fix any wrong slashes in filePath itself though, would it?

[Timer]

No, it doesn't, but we always pass it /, and path.win32 switches those to \.
See https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/utils/createJestConfig.js#L24.

[gaearon]

I was looking at "setupFiles": [ "<rootDir>\\config\\polyfills.js" ] from #1417. Doesn't this mean the whole path needs to be fixed?

[Timer]

To clarify, path.win32 supports / and \ (and outputs \) but path.posix only supports /.

See this discrete note at the bottom: https://nodejs.org/api/path.html#path_path_win32

[Timer]

I was looking at "setupFiles": [ "\config\polyfills.js" ] from #1417. Doesn't this mean the whole path needs to be fixed?

The problem is that the windows flavor of path.join will switch / to \, this prevents that from happening. We always pass it / so we don't need to fix the whole path.

[gaearon]

You're right, just checked. 👍

[gaearon]

I also want to know if we can replace this and this with simpler expressions. I guess I could test that myself.

[Timer]

I don't have a windows machine on me right now (will in a few hours), I messaged you on twitter.

[Timer]

path.posix doesn't replace \ with / so we have to do it manually.
/cc @gaearon

[Timer]

I also want to know if we can replace this and this with simpler expressions. I guess I could test that myself.

I think it's best to keep that for potential compatibility issues/regressions in the future. If Jest normalizes the path on windows before that is applied we'll still need to check for \.

Jest seems to be bipolar on the subject.
See sample testPathIgnorePatterns and sample testRegex.
One checks for windows separator and the other doesn't.

[gaearon]

Can we fix this in Jest then?

[gaearon]

Hmm. Can we use testMatch instead of testPathIgnorePatterns?
Seems like it's newer and supports globs.

[Timer]

I actually was about to edit my comment ... I'm not sure if that is a regex literal or string, they may not be bipolar.
I'm looking specifically at (\\.|/) which could be /(\\.|/)/ or /(\.|/)/ (escaping dot or matching \ and dot).

[gaearon]

Oops, testMatch is 19+ only. I guess it's a good way forward, but can't do it yet.

[Timer]

Before:

{
  "name": "test1",
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js --env=jsdom"
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx}"
    ],
    "setupFiles": [
      "<rootDir>\\config\\polyfills.js"
    ],
    "testPathIgnorePatterns": [
      "<rootDir>[/\\\\](build|docs|node_modules|scripts)[/\\\\]"
    ],
    "testEnvironment": "node",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>\\config\\jest\\cssTransform.js",
      "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>\\config\\jest\\fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web"
    }
  }
}

Joes-MacBook-Pro:test1 joe$ CI=true npm test

> [email protected] test /Users/joe/Desktop/test1/test1
> node scripts/test.js --env=jsdom

Error: Jest: Module "<rootDir>\config\polyfills.js" in the "setupFiles" option was not found.
    at resolve (/Users/joe/Desktop/test1/test1/node_modules/jest-config/build/normalize.js:48:11)
    at Array.map (native)
    at Object.keys.reduce.e (/Users/joe/Desktop/test1/test1/node_modules/jest-config/build/normalize.js:310:29)
    at Array.reduce (native)
    at normalize (/Users/joe/Desktop/test1/test1/node_modules/jest-config/build/normalize.js:294:23)
    at promisify.then (/Users/joe/Desktop/test1/test1/node_modules/jest-config/build/loadFromPackage.js:24:12)
npm ERR! Test failed.  See above for more details.

After:

{
  "name": "test2",
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js --env=jsdom"
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx}"
    ],
    "setupFiles": [
      "<rootDir>/config/polyfills.js"
    ],
    "testPathIgnorePatterns": [
      "<rootDir>[/\\\\](build|docs|node_modules|scripts)[/\\\\]"
    ],
    "testEnvironment": "node",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web"
    }
  }
}

Joes-MacBook-Pro:test2 joe$ CI=true npm test

> [email protected] test /Users/joe/Desktop/test1/test2
> node scripts/test.js --env=jsdom

 PASS  src/App.test.js
  ✓ renders without crashing (19ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        0.918s, estimated 1s
Ran all test suites.

[Timer]

Tests also work on windows still.

[Timer]

Will land this once CI passes.