Incorrect Error About Locating @angular/core in Yarn Workspaces Monorepo [Regression]

[michaelfaith]

🐛 Bug Report

We have a monorepo with yarn workspaces, and Angular 12, Jest 27. This all worked with 9.0.4, but updating to 9.0.6 is incorrectly throwing an error about not being able to locate @angular/core (which is at the root node_modules, not the local node_modules). I'm assuming it's related to this change: c35d3f2
Rolling back to 9.0.4 fixes it.

Expected behavior

Should run in monorepo environment.

Error log:

# content of error stacktrace :
Error: Cannot locate the '@angular/core' directory, resolved as C:\Users\<user>\src\fabric\projects\components\node_modules\@angular\core. Please make sure you are running 'ngcc-jest-processor.js' from root level of your project
    at Object.<anonymous> (C:\Users\<user>\src\fabric\node_modules\jest-preset-angular\build\utils\ngcc-jest-processor.js:42:11)
    at Module._compile (internal/modules/cjs/loader.js:1068:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1097:10)
    at Module.load (internal/modules/cjs/loader.js:933:32)
    at Function.Module._load (internal/modules/cjs/loader.js:774:14)
    at Module.require (internal/modules/cjs/loader.js:957:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (C:\Users\<user>\src\fabric\node_modules\jest-preset-angular\ngcc-jest-processor.js:1:18)
    at Module._compile (internal/modules/cjs/loader.js:1068:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1097:10)
error Command failed with exit code 1.

envinfo

System:
    OS: Windows 10

Npm packages:
    jest: 27.0.6
    jest-preset-angular: 9.0.6
    typescript: 4.3.5

[ahnpnl]

We introduced this to inform user that the util script needs to be explicitly run at root of the project to be able to run ngcc correctly.

It's either can be a warning or throw error, that I wasn't sure so I made it to throw error.

[michaelfaith]

Error or warning isn't really the issue, so much as it's assuming the node_modules is adjacent to the package.json, and in yarn workspace setup it isn't. So it's mis-identifying the location that it's looking for.

[ahnpnl]

in the case of yarn workspace, the util script invokes ngcc but ngcc doesn't process node_modules correctly (which I tested with your project). How do we inform users about that?

[michaelfaith]

It would probably be ok to just change it to warning and relax the language a bit. Something like "Warning: Could not locate @angular/core to run ngcc automatically. Please be sure to run ngcc prior to testing." Something that let's people know in case they do have a problematic setup, but doesn't error out on people who don't? Either that or improve the logic that tries to find the library

[ahnpnl]

I think changing to warning is the only way. We invoke ngcc directly from @angular/compiler-cli which we can't change the logic how it looks for node_modules :)

[michaelfaith]

We invoke ngcc directly from @angular/compiler-cli which we can't change the logic how it looks for node_modules :)

I meant this logic, where it just defaults to cwd and then appends node_modules. It doesn't walk up the tree, or anything more expansive.

const nodeModuleDirPath = findNodeModulesDirectory(process.cwd());
const canRunNgcc =
  !process.argv.find((arg) => IGNORE_ARGS.includes(arg)) && existsSync(join(nodeModuleDirPath, '@angular', 'core'));
function findNodeModulesDirectory(startPoint: string): string {
  let current = startPoint;
  while (dirname(current) !== current) {
    const nodePath = join(current, 'node_modules');
    if (existsSync(nodePath)) {
      return nodePath;
    }

    current = dirname(current);
  }

  throw new Error(
    `Cannot locate the 'node_modules' directory. Please make sure you are running jest from root level of your project`,
  );
}

[ahnpnl]

Oh ye that one is assuming that this script is run from top of the project but doesn’t take into account of Yarn workspace.

I’m curious if ngcc works with cwd instead of from root? Probably using require.resolve on @angular/compiler-cli to find real path to node_modules and fetch that to the script.

[michaelfaith]

Yeah, I don't believe it does. For example, if ngcc is set as a postinstall step on the lower package.json it doesn't find the libraries. I have to add it as a postinstall at the top/root package.json for it to find everything.

[michaelfaith]

@ahnpnl thanks for the quick work on this. Really appreciate it.