How to share code between TypeScript projects?

Question

Let\'s say I have two projects with following file structure

/my-projects/

  /project-a/
    lib.ts
    app.ts
    tsconfig.json

  /project-b/
    app.ts           


        

Answer 1

In a similar scenario, where I also wanted to avoid the overhead of having to perform an NPM release, I went for the following structure (after lots of trial and error and failed attempts):

/my-projects/

  /node_modules/
    /my-lib/
      lib.ts
      tsconfig.json
      package.json

  /project-a/
    app.ts
    tsconfig.json

  /project-b/
    app.ts         
    tsconfig.json

The central idea is to move the shared stuff to a node_modules directory above the individual projects (this exploits NPMs loading mechanism, which would start looking for dependencies in the current directory and then move upwards).

So, project-a and project-b can now access the lib simply via import { Whatever } from 'my-lib'.

Notes:

1. In my case, my-lib is actually only for shared typings (i.e. .d.ts files within a lib subdirectory). This means, I do not explicitly need to build my-lib and my my-lib/package.json looks as follows:

   {
     "name": "my-types",
     "version": "0.0.0",
     "private": true,
     "types": "lib/index"
   }
   

2. In case my-lib contains runnable code, you’ll obviously need to build my-lib, so that .js files are generated, and add a "main" property to the package.json which exposes the main .js file.

3. Most important: Despite its name, /my-projects/node_modules only contains custom code, no installed dependencies (they are actually in the individual projects project-a/node_modules and project-b/node_modules). This means, there’s an explicit git ignore setting, which un-ignores the /node_modules directory from being committed.

Is this a clean solution? Probably not not. Did it solve my issue? Yes. Am I happy to hear about improvement suggestions? Absolutely!