docs: how to execute e.g. combined with ts-jest?

[dnmd]

This project seems a nice fit for constructing dynamic paths within the tsconfig.json where based on e.g. an environment variable a different directory is used to e.g. load different data sets.

The only thing I miss here is how to 'execute' or trigger e.g. the tsconfig.js/once? Maybe I am overthinking things to much, but do I place it within my package.json's script or jest.config.js? In my scenario I use ts-jest and have the following setup;

( minimal repo: https://github.com/dnmd/ts-jest-tsconfig.js )

package.json

  "scripts": {
    "test": "jest"
  },

jest.config.js

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  moduleNameMapper: {
    // as this file is already a .js file I can user `${process.env.NODE_ENV}` here already pointing to e.g. dev or test
    '^app/(.*)$': `<rootDir>/${process.env.NODE_ENV}/$1`,
  }
};

tsconfig.json

// tsconfig.json
{
    "compilerOptions": {
        "baseUrl": ".",
        "paths": {
            "@app/*": [
                // ====> here I also would like to use the environment var to point to a different path depending on the env.
                // `src/${process.env.NODE_ENV}/*`
                "src/*"
            ]
        }
    }
}

[c-vetter]

Hello @dnmd
Thank you for reaching out! 🙂
I'm sorry for the late reply, I'm swamped with other work.

Regarding your query, I'm actually unsure what exactly you are trying to accomplish, but I'll try to help towards what I understand. It's been quite some time since I've used jest, so I may be overlooking something. Please elaborate accordingly.

In order to trigger a single run before any run of npm test, you can just add a pretest script to your package.json, like so:

    "pretest": "npx tsconfig.js --once --extensions=ts",
    "test": "jest"

I've added it to your repo: https://github.com/rasenplanscher/ts-jest-tsconfig.js

---

Note that it's necessary to add a loader, and unfortunately, there's an error preventing the related message to be printed when this is not fulfilled.

I will have to update the docs, and also fix that error, which I found while answering your question.