fix(testing): issue passing coverageRepoters commandline

[kristofdegrave]

In Jest coverageReporters are an array of strings (https://jestjs.io/docs/en/configuration#coveragereporters-arraystring). In here it is an optional string.

Current Behavior (This is the behavior we have today, before the PR is merged)

When passing a string value for the coverageReporters to the command line, it results into the following error:

Failed to write coverage reports:
ERROR: TypeError: coverageReporters.forEach is not a function
STACK: TypeError: coverageReporters.forEach is not a function

Expected Behavior (This is the new behavior we can expect after the PR is merged)

Use the provided coverageReporter

Issue

[vsavkin]

Thank you so much for your PR!

I'm not sure if the fix is right. options.coverageReporters is plural, so you should be able to pass more than one, right? I'd update the unit tests to make sure that use case is covered.

[kristofdegrave]

You are correct, but didn't want to change the current contract, because I'm not sure if it would break with other testing frameworks. I think the angular cli only allows one reporter. If it is Ok for you I can change it.

[dgsmith2]

This problem/fix here seems very much like #1854.

I'm working on some code to restore --coverage (#2569) because it falls into the same use case as #1852.

Is there anything I can do to help this move along?

[vsavkin]

Sorry for the late reply, folks. I'm a bit confused about the current state. You are saying that currently the coverageReporters option cannot be used, right? It only accepts a string, and Jest expect an array. Is this the case in Nx 9.3?

[kristofdegrave]

It still seems to be a single string

nx/packages/jest/src/builders/jest/schema.json

Lines 119 to 122 in b5025ef

	"coverageReporters": {
	"description": "A list of reporter names that Jest uses when writing coverage reports. Any istanbul reporter",
	"type": "string"
	},

nx/packages/jest/src/builders/jest/schema.d.ts

Line 29 in b5025ef

coverageReporters?: string;

[vsavkin]

I'm really sorry folks for the late reply. I think we should change the schema to accept an array of string instead of wrapping the provided value into an array.

"coverageReporters": {
"description": "A list of reporter names that Jest uses when writing coverage reports. Any istanbul reporter",
"type": "array",
"items": {
"type": "string"
}
}

With this change, we will be able to do:

nx test myproj --coverageReporters=json,text

[kristofdegrave]

@vsavkin that should be the best solution :). But I wasn't sure that it would conflict with the schema of the angular-cli. That is why I solved it this way.

[vsavkin]

Changing the schema of the jest builder won't affect or by affected by the Angular CLI. We aren't wrapping an existing builder, so we can come up with any schema we want.

[vsavkin]

@kristofdegrave, please let me know if you need any help with this. I know I haven't been the quickest communicator here, so if you don't have time to finish it up, it's totally OK. I can do it in this case, but I'll keep you as a commit author.

[vsavkin]

Sorry folks, but I'm going to close this PR. I'm trying to keep the PR list short to reflect the things that are currently being worked on

[github-actions]

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