[SOLVED] Jest "Could not locate module" if any dependency has "src" in path

Jest "Could not locate module" if any dependency has "src" in path

In my react app, I am importing a module as follows:

import { isValidAddress } from 'orbit-db';

Some dependency of isValidAddress requires multicodec/src/base-table (see this line).

However, jest gives the following error:

Configuration error:

Could not locate module multicodec/src/base-table mapped as:
/Users/h/Documents/code/orbit-db-time-machine/src/base-table.

Please check your configuration for these entries:
{
  "moduleNameMapper": {
    "/src\/(.*)$/": "/Users/h/Documents/code/orbit-db-time-machine/src/$1"
  },
  "resolver": null
}

I think that this is happening because the jest dependency rule "/src\/(.*)$/" is re-writing all paths with src in them to <rootDir>/src, even if they come from a npm module.

I tried to fix this by adding the following config to my package.json:

"jest": {
  "moduleNameMapper": {
    "/multicodec\/(.*)$/": "<rootDir>/node_modules/multicodec/$1"
  }
}

However, this did not change the error. The only way I have been able to remove the error is by removing my import statement - however, this is required in my code.

Note: The code works when run from my react app, it only breaks when I run jest.

Solution