[Bug] nyc fails with PnP on Windows

[clemyan]

• I'd be willing to implement a fix

Describe the bug

When using PnP on Windows, running nyc fails with the following error:

C:\path\to\project\.pnp.js:6338
    throw firstError;
    ^

Error: Your application tried to access node-preload.js, but it isn't declared in your dependencies; this makes the require call ambiguous and unsound.

Required package: node-preload.js (via "node-preload.js")
Required by: C:\path\to\project\

Require stack:
- internal/preload
    at internalTools_makeError (C:\path\to\project\.pnp.js:6082:34)
    at resolveToUnqualified (C:\path\to\project\.pnp.js:7034:23)
    at resolveRequest (C:\path\to\project\.pnp.js:7132:29)
    at Object.resolveRequest (C:\path\to\project\.pnp.js:7198:26)
    at Function.external_module_.Module._resolveFilename (C:\path\to\project\.pnp.js:6315:34)
    at Function.external_module_.Module._load (C:\path\to\project\.pnp.js:6180:48)
    at Module.require (internal/modules/cjs/loader.js:1089:19)
    at Module._preloadModules (internal/modules/cjs/loader.js:1345:12)
    at loadPreloadModules (internal/bootstrap/pre_execution.js:439:5)
    at prepareMainThreadExecution (internal/bootstrap/pre_execution.js:71:3)

This does not happen and nyc correctly collects coverage when:

• using the node-modules linker
• running nyc inside a docker container using WSL2 backend
• running nyc on a Linux (specifically CentOS 7) VM

To Reproduce

The minimal information needed to reproduce your issue (ideally a package.json with a single dep). Note that bugs without minimal reproductions might be closed.

IMPORTANT: We strongly prefer reproductions that use Sherlock. Please check our documentation for more information: https://yarnpkg.com/advanced/sherlock

Reproduction

const { promises: { writeFile } } = require('fs')

await packageJsonAndInstall({
    devDependencies: {
        nyc: '^15.1.0'
    }
})
await writeFile('test.js', 'console.log("test")')

await expect(yarn('nyc', 'node', 'test.js')).resolves.toBeTruthy()

Environment if relevant (please complete the following information):

• OS: Windows 10 Home Build 19041.508
• Node version: 14.11.0, 12.18.4
• Yarn version: 2.2.2, 2.2.2-git.20200914.bc3c466e

Additional context

istanbuljs/nyc#1308 probably relevant? However, unlike pnpm, running yarn nyc --use-spawn-wrap (Windows, PnP) will cause nyc to not run the given test command at all and collects no coverage.

[yarnbot]

We couldn't reproduce your issue (all the assertions passed on master).

[clemyan]

I have done some more investigation on this issue and have a workaround for now.

tl;dr: nyc 15 on Window injects its instrumentation by adding a script's dirname to NODE_PATH and then --require its basename in NODE_OPTIONS. Seems like Node cannot deal with a zipfs paths in NODE_PATH. Workaround: downgrade to [email protected] via resolutions.

So, nyc 15 is uses node-preload under the hood to inject its instrumentation. node-preload, in turn, injects itself by monkey-patching child_process to change the environment variables being passed to all spawned processes. In particular, it changes NODE_OPTION to add a --require flag.

However, Node before v12 cannot use a quoted path for --require, which means it cannot --require a path containing spaces. In these cases node-preload adds the path's dirname to NODE_PATH and basename to --require (since basename is always node-preload.js that would not cause problems).

In node-preload 0.2.0, that behavior is only enabled for Node pre-v12, Node v12+ uses a quoted path with --require. However that causes problems when a Node v12+ process spawns a Node pre-v12 process. node-preload 0.2.1 fixes that by always enabling that behavior for paths containing spaces, double quotes and/or backslashs.

But that means that behavior is always enabled on Windows since the paths to node-preload.js always have backslashs. That would add a zipfs path to NODE_PATH which Node seems to be unable to deal with.

As noted, I am working around that by downgrading to node-preload v0.2.0. Hopefully node-preload will always use the quote path method when Node v10 maintenance ends.