Jest doesn't follow files in a symlink folder and tries to use the main shared folder

Question

The question is - how to force Jest to follow symlinked shared folder file structure but not main shared folder?

I have the next files structure:

root
├── projects
│   ├── A
│   │   ├── node_modules
│   │   ├── shared (symlink ../../shared-main)
│   │   ├── components
│   │   ├── settings.ts
│   ├── B
│   │   ├── node_modules
│   │   ├── shared (symlink ../../shared-main)
│   │   ├── components
│   │   ├── settings.ts
├── shared-main
│   ├── utils.ts
│   ├── config.ts

In my projects, A and B, I use utils from the shared folder. Utils.ts uses config.ts where imports settings files by path './settings.ts', but inside the shared-main folder, it looks like "file doesn't exist" (it is ok). But Jest in a project's tests when it meets using a shared file test fails with the error: "../../shared-main/config.ts:9:35 - error TS2307: Cannot find module '../settings' or its corresponding type declarations."

How to get around this and force Jest to use config.ts from the symlink folder instead of the main one?

Answer 1

How about "testRegex": ["test/.*.[jt]s"], in your jest config so it doesn't try and find shared files, if you're using shared files across multiple projects then no single project should test those files, they should only test their own files.

However I'm not so sure that symlinks are your problem, when using typescript like this and trying to use files outside of your project rootDir it will not find the types for it or it will complain that it can't find the types for it if you've added it to tsconfig include/exclude. Right now I can only assume that you're using tsc --project with specific config files for each project.

// tsconfig.json

"include": ["projectA/**/*.ts"],

If you've done something like that then it won't find any types outside of projectA so anything in config.ts and utils.ts will not have any types or be able to find any modules, unless they're included in your tsconfig.

To show a simpler example if I have:

// tsconfig.json

...
includes: ["src/**/*.ts"]
...

Along with a directory structure like this:

- tsconfig.json
- example.ts
- src

Then anything in example.ts will not be able to find its types or module imports.

The way I get around this issue in my project is to use ts-jest along with specifying where to find tests, along with overriding the globals rootDir.

// .jestrc.json

"testRegex": ["test/.*.[jt]s"],

...

"globals": {
  "ts-jest": {
    "tsconfig": {
      "rootDir": "."
    }
  }
}