jest-resolve fails on network drives and RAM-drives on Windows

[asapach]

💥 Regression Report

Starting with jest@23 our tests started failing when using a RAM-drive on Windows (we are using a tool called ImDisk). The same can be reproduced when using a network drive (net use).

Last working version

Worked up to version: v22.4.4

Stopped working in version: v23.0.0

To Reproduce

Steps to reproduce the behavior:

1. Follow the Getting Started guide and create a simple test suite
2. Create a network drive e.g. net use x: \\localhost\c$\tmp
3. Open the command line in x: and run yarn test / npm test

Expected behavior

Test suite should pass.

Actual behavior

Resolution fails with different kinds of errors, e.g.:

    Cannot find module 'source-map-support' from 'source-map-support.js'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:221:17)

or

   EISDIR: illegal operation on a directory, realpath '...\node_modules\regenerator-runtime'

     at realpathSync (node_modules/realpath-native/index.js:25:32)

Run npx envinfo --preset jest

Paste the results here:

  System:
    OS: Windows 8.1
    CPU: x64 Intel(R) Core(TM) i5-4200M CPU @ 2.50GHz
  Binaries:
    Yarn: 1.7.0 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
    npm: 5.6.0 - C:\Program Files\nodejs\npm.CMD

[asapach]

The issue was introduced in #5085. If I roll it back it works fine.
My understanding is that fs.realPath() uses a more modern API on Windows (GetFinalPathNameByHandle()), which is not supported by older drivers.

Is it possible to hide the symlinks resolution logic behind an option e.g. followSymlinks (enabled by default) so that the old behavior would be preserved?

(CC @nickpape-msft)

[SimenB]

None on the team uses Windows, so I'm afraid this won't be fixed without help from the community. I'm also unsure what the correct solution would be, if to fix your issue we have to rollback a fix to another one...

[asapach]

I'm not proposing to roll it back, I'd prefer to have an option that would allow to switch between the two modes. I can create a PR if that's OK.

[SimenB]

Having an option for this in jest's config should be the last resort, I think. I suppose we could add it as an option to jest-resolve and then you could set up a custom resolver in your project

[asapach]

Yes, sorry, I meant jest-resolve options. We're already using a custom resolver in our project, so that should work fine.

[SimenB]

PR for that would be most welcome :)

[asapach]

@SimenB I'm almost there (I've got a fork ready: https://github.com/asapach/jest/tree/symlinks), but I got stuck. I can create a custom resolver and pass my options, but there's a root resolver created in jest-runtime and I can't pass any extra options there unless I add them to ProjectConfig:
https://github.com/facebook/jest/blob/c4007d7bc6b6b97c2016af5872b461c2e85ce4ac/packages/jest-runtime/src/index.js#L250-L261

It does not delegate to custom resolver and fails here:
https://github.com/facebook/jest/blob/c4007d7bc6b6b97c2016af5872b461c2e85ce4ac/packages/jest-runtime/src/index.js#L588

Do you have any suggestions how to work around that? Any help is appreciated.

[SimenB]

Auch... @thymikee thoughts? I'm not familiar with this part of the code base

[thymikee]

I guess we'll need to add a new project option followSymlinks for that.

[asapach]

I took a look and I think it's not feasible to pass the option correctly to every resolve call. This would affect jest-config, jest-resolve and jest-runtime. I'll probably abandon this route.

I have an alternative proposal: we could call fs.lstatSync() and stats.isSymbolicLink() before calling realpath():
https://github.com/facebook/jest/blob/c93e02718480b9f25b0d28f33456ed159bd11b69/packages/jest-resolve/src/node_modules_paths.js#L44-L52
That would verify that realpath is resolved only for symbolic links, which solves the issue as well.
What do you guys think?

[thymikee]

How would that affect resolve performance?

[asapach]

"Happy path" should not be different - one realpath.native call will be replaced by lstat call (which is probably faster).
"Symlink path" would incur two calls, but that should be relatively rare.
Do you guys run benchmarks to compare the results?

[thymikee]

We don't have a special suite for that. Usually checking on Jest, React, maybe Webpack codebase. Also @mjesun and @aaronabramov make sure everything runs smoothly on FB, so you can ask them to test your diff

[asapach]

OK, thanks. I'll get the PR ready tomorrow.

[gsteacy]

I'm interested to test this as well, though I may not get a chance for a few days. #5085 had a measurable negative impact on performance so I'd be concerned about adding even more overhead. However, I'd also be pleased if overhead was reduced. :)

[asapach]

As promised, here's the PR: #6906

[webuniverseio]

I was getting

 Cannot find module 'source-map-support' from 'source-map-support.js'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:221:17)

Changing

"moduleDirectories": ["/node_modules/"],

to

"moduleDirectories": ["node_modules"],

fixed the issue

[ivancuric]

Haven't managed to get it working. Any updates on this?

I'm running babel 7.
My jest.config.js looks like this:

module.exports = {
  testEnvironment: 'node',
  roots: ['<rootDir>/src'],
  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
  collectCoverageFrom: ['src/**/*.{ts,tsx}'],
  clearMocks: true,
  setupFilesAfterEnv: ['<rootDir>/src/setupEnzyme.ts'],
  moduleNameMapper: {
    '\\.(gif|ttf|eot|svg)$': '<rootDir>/__mocks__/fileMock.js',
  },
};

And my .babel.config.js is

module.exports = {
  presets: [
    [
      '@babel/preset-env',
      {
        targets: {
          node: 'current',
        },
      },
    ],
    '@babel/preset-typescript',
  ],
  plugins: [
    '@babel/proposal-class-properties',
    '@babel/proposal-object-rest-spread',
  ],
};

When running either jest --rootDir . or jest, I'm getting the following error:

● Validation Error:

  Module ts-jest in the transform option was not found.
         <rootDir> is: \\Mac\Home\Dev\

With a minimal setup like

module.exports = {
  testEnvironment: 'node',
  transform: {
    '^.+\\.(js|jsx|ts|tsx)$': 'babel-jest',
  },
  moduleDirectories: ['node_modules', 'src'],
  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
};

I get

FAIL  src/ui/crashDump.test.ts
  ● Test suite failed to run

    Cannot find module 'source-map' from 'source-map-support.js'

      at Resolver.resolveModule (Z:/Dev/***/node_modules/jest-resolve/build/index.js:203:17)
      at Object.<anonymous> (node_modules/source-map-support/source-map-support.js:1:114)

[rahulcyadav]

facing this issue...what is the solution?

[avgalon]

I too have this problem.
I get this(F is a ram drive on win10):
Error: EISDIR: illegal operation on a directory, realpath 'F:_work\2\s\client'
at Function.realpathSync.native (fs.js:1521:3)
at realpathSync (F:_work\2\s\client\node_modules\realpath-native\index.js:29:28)
at Object. (F:_work\2\s\client\node_modules\jest-resolve\build\index.js:85:48)
at Module._compile (internal/modules/cjs/loader.js:778:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Module.require (internal/modules/cjs/loader.js:692:17)
at require (internal/modules/cjs/helpers.js:25:18)
jest config:

module.exports = {
  reporters: [
    "default",
    [
      "jest-junit",
      {
        outputDirectory: "<rootDir>"
      }
    ]
  ],
  coverageReporters: [
    "text",
    "cobertura"
  ],
  preset: "jest-preset-angular",
  setupFilesAfterEnv: ["<rootDir>/src/setupJest.ts"],
  cacheDirectory: '<rootDir>/.cache',
  testMatch: ['<rootDir>/src/app/**/*.spec.ts'],
  testPathIgnorePatterns: ['<rootDir>/node_modules', '<rootDir>/vendors'],
  transform: {
    '^.+\\.ts?$': 'ts-jest',
    '^.+\\.scss?$': 'jest-transform-css'
  },
  collectCoverage: true,
  modulePathIgnorePatterns: ['<rootDir>/src/mocks/*/*.mock.ts'],
  transformIgnorePatterns: [
    "node_modules/(?!@cellebrite/ui-components)"
  ],
  globals: {
    'ts-jest': {
      tsConfig: '<rootDir>/src/tsconfig.spec.json',
      stringifyContentPathRegex: '\\.html$',
      astTransformers: ['jest-preset-angular/InlineHtmlStripStylesTransformer.js']
    }
  }
};

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