How to use TS Path Mapping with Firebase Cloud Functions

Question

How do I use TS Path Mapping with Firebase Cloud Functions? I tried without success:

"baseUrl": ".",
  "paths": {
    "@custom-path/*": ["src/utils/*"],
    "@other-path/*": ["../other/path/*"]
  }

Answer 1

Finally I was able to do this with module-alias NPM package.

1. Install it as non-dev dependency: yarn add module-alias @types/module-alias
2. Create a file fixTsPaths.ts or whatever with content like this:

import * as ModuleAlias from 'module-alias';

ModuleAlias.addAliases({
    'common': __dirname + '/../../../common',
});

Here's the trick about the path /../../../common: in my case this folder is outside functions, and Typescript replicates folders structure during the build, so that's could be the reason why https://github.com/dividab/tsconfig-paths was not working out of the box. So in every case one needs to check this path and find appropriate '..' count :)

3. And finally import this file in your index.ts at the very top:

import './fixTsPaths';

Hope this helps!

Answer 2

The problem is the rule no-implicit-dependencies: true on the tslint.json. You can pass additional params to whitelist your custom paths:

"no-implicit-dependencies": [true, ["@custom-path", "@other-path"]],