Adding tests to CRA example yields an error

[akutruff]

When trying to setup CRA example for tests, I set package.json to:

  "scripts": {
    "start": "cross-env SKIP_PREFLIGHT_CHECK=true craco start",
    "build": "cross-env SKIP_PREFLIGHT_CHECK=true craco build",
    "test": "cross-env SKIP_PREFLIGHT_CHECK=true craco test"
  },

I also added the jest.config.ts to the directory and added jest dependencies.

Edit: in general, adding tests to a project where the tests and the projects live in the same directory is causing issues. I added a basic TypeScript library with jest tests and those break under GitHub CI.

I get the following failure when trying to run the tests.

node ➜ /workspaces/mono-repo-test/examples/cra (master ✗) $ yarn test
yarn run v1.22.15
$ cross-env SKIP_PREFLIGHT_CHECK=true craco test
The following changes are being made to your tsconfig.json file:
  - compilerOptions.paths must not be set (aliased imports are not supported)

● Validation Error:

  Watch plugin jest-watch-typeahead/filename cannot be found. Make sure the watchPlugins configuration option points to an existing node module.

  Configuration Documentation:
  https://jestjs.io/docs/configuration.html

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[NiGhTTraX]

Hey @akutruff, this looks like facebook/create-react-app#11043.

I also added the jest.config.ts to the directory and added jest dependencies.

With CRA you shouldn't have to manually add jest — react-scripts test (or in this case craco test) should come with everything you need.

FWIW, everything is working fine for me locally. Maybe run yarn why jest-watch-typeahead to see where the dependency the error complains about is located in the monorepo. This is what I get:

❯ yarn why jest-watch-typeahead       
yarn why v1.22.0
[1/4] Why do we have the module "jest-watch-typeahead"...?
[2/4] Initialising dependency graph...
[3/4] Finding dependency...
[4/4] Calculating file sizes...
=> Found "jest-watch-typeahead@0.6.1"
info Reasons this module exists
   - "_project_#@nighttrax#cra-example#react-scripts" depends on it
   - Hoisted from "_project_#@nighttrax#cra-example#react-scripts#jest-watch-typeahead"

[akutruff]

Thanks for looking into this and the repo.

package.json has yarn run build for the test script which doesn't execute tests, it just builds it right?

  "scripts": {
    "start": "cross-env SKIP_PREFLIGHT_CHECK=true craco start",
    "build": "cross-env SKIP_PREFLIGHT_CHECK=true craco build",
    "test": "yarn run build"
  },

[NiGhTTraX]

@akutruff yes, all of the test scripts here just build the respective package because that's the main objective of this repo - building packages in a monorepo. The jest example covers running actual tests in a monorepo.

---

P.S.: the script name is test because it's run in CI and building is what I'm testing for. I should change this because it is confusing...

[akutruff]

#160

I tried to take this as far as I could, but I still can't get the Button component to resolve. The jest module resolver customization isn't making sense to me unfortunately.

[NiGhTTraX]

@akutruff I left some comments in #160, it looks like craco has some quirks when it comes to jest.config.

[NiGhTTraX]

For anyone coming here for the jest-watch-typeahead problem, see d931391.