EF TypeScript Path Mapper

A Node binary that can be easily added to a build process to (re-)map TypeScript module mappings to the correct relative path.

TypeScript path mappings can help reduce relative import paths in the code base. However, they are passed verbatim to the output.

tsconfig.json

{
  "compilerOptions": {
    "module": "ES2015",
    "target": "ES2017",
    "moduleResolution": "node",
    "outDir": "dist",
    "rootDir": "./",
    "baseUrl": "./",
    "paths": {
      "@lib/*": ["lib/*"]
    }
  },
  "include": [
    "bin/**/*",
    "lib/**/*"
  ],
  "exclude": [
    "**/*.test.ts",
    "node_modules"
  ]
}

lib/myFunction.ts

export default function myFunction(lhs: number, rhs: number ): void {
  console.log(lhs + rhs);
}

lib/some/nested/path/abc.ts

import myFunction from '@lib/myFunction';  // no need for '../../../myFunction'

myFunction(1, 2);  // 3

Once built the output files retain the path mappings.

dist/lib/some/nested/path/abc.js

import myFunction from '@lib/myFunction';  // not '../../../myFunction'

myFunction(1, 2);  // 3

Adding ef-tspm as a post-build step (re-)maps the paths so that they work correctly. It will automatically configure itself from the tsconfig.json settings.

package.json

{
  "scripts": {
    "postbuild": "ef-tspm"
  }
}

dist/lib/some/nested/path/abc.js

import myFunction from '../../../myFunction';  // now works with normal resolutions

myFunction(1, 2);  // 3