Description
openedon Feb 16, 2024
Command
test
Description
How does one debug jest tests?
Debugging a normal jest test run is documented here: https://jestjs.io/docs/troubleshooting#debugging-in-vs-code. It describes using jest with --runInBand. However, there is no way to use --runInBand with ng test:
ng test --help
ng test [project]
Runs unit tests in a project.
Arguments:
project The name of the project to build. Can be an application or a library. [string] [choices: "datepicker"]
Options:
--help Shows a help message for this command in the console. [boolean]
-c, --configuration One or more named builder configurations as a comma-separated list as specified in the "configurations" section in angular.json.
The builder uses the named configurations to run the given target.
For more information, see https://angular.io/guide/workspace-config#alternate-build-configurations. [string] [choices: "jest", "karma"]
--exclude Globs of files to exclude, relative to the project root. [array]
--include Globs of files to include, relative to project root. [array]
--polyfills A list of polyfills to include in the build. Can be a full path for a file, relative to the current workspace or module specifier. Example: 'zone.js'. [array]
--ts-config The name of the TypeScript configuration file.
See also related issue: #25434.
Describe the solution you'd like
In my comment I suggest a way to run ng build --test (or ng test --build). It can run the build step before jest runs. This allows us to run jest --runInBand ourselves.
Another approach would be to add a --runInBand ng test flag for jest.
Describe alternatives you've considered
I've currently invented a workaround. Unfortunately, without a proper ng test --build command, I had to revert to ng test || exit 0. This will build and run the tests once before debugging can start. The necessary sourceMapPathOverrides are hideous as well 🙈
launch.json
{
"version": "0.2.0",
"configurations": [
{
"name": "ng test (jest)",
"request": "launch",
"preLaunchTask": "npm: test:build",
"runtimeArgs": [
"--experimental-vm-modules",
"./node_modules/jest/bin/jest.js",
"--runInBand",
"--rootDir",
"${workspaceFolder}/dist/test-out/browser",
"--testMatch",
"**/?(*.)+(spec|test).mjs"
],
"skipFiles": ["<node_internals>/**"],
"type": "node",
"sourceMapPathOverrides": {
"src/app/*": "${workspaceFolder}/src/app/*"
},
"outputCapture": "std",
"outFiles": ["${workspaceFolder}/dist/**/*.mjs"]
}
]
}package.json
{
"scripts": {
"test": "ng test",
"test:build": "npm test || exit 0",
}
}