ts-module-export-map

Caution

This code was written in June 2021 when the ecosystem and knowledge around the TS Compiler API was limited. Currently there is a much better, open-source alternative available which does a much better job than this code. Check out ts-morph's getExportedDeclarations(). This lacks the reExportPath and originalLocation functionality of my code but I'm sure you can get that to work with a little work by looping over the source files if you really need it

What is it

ts-module-export-map is a small tool to determine what your TypeScript module exports.

Ofcourse you could require('module') or import * as myModule from 'module' and iterate over the enumerable properties, but that would only include symbols (exports) that are available runtime.

This tool also includes TypeScript specific entities such as enum, interface and types.

This tool also provides insights in the intermediate files between the declaration of the symbol (export) and the entrypoint. This feature is particularly useful if you have (a lot of) files that re-export such as export * from './directory/module'

Features

• Only follows symbols that are available in the entry point (it respects partial exports such as export { iAmReExported } from './partial-export';, where more symbols are exported in './partial-export')
• Supports most (if not all) ways of declaring an export
• Supports exported functions, interfaces, enums, vars, lets, consts
• Supports tsConfig.compilerOptions.paths aliases (if you use --tsConfigJson)
• Supports both .ts and .tsx files

Limitations

• Anything that is re-exported from a node_module package is ignored
• Only takes a single entry point
• Reports back paths, not aliases
• Has only been tested on typescript version 3.5.3. It might work on other versions, but I haven't tested it.
• Symbols with the same name are ignored (if const foo is declared in multiple files you'll get weird results)

Usage

This project has NOT been published to NPM yet.

If you'd like to use this in your own project, the best approach would be to copy the files under ./src to your own project and run it using ts-node. The other required dependencies are yargs and typescript.

In the tsconfig.json make sure to add this configuration or the script will not run:

  "ts-node": {
    "compilerOptions": {
      "module": "commonjs"
    }
  }

Then on the command line run the script (the location of main.ts and tsconfig.json and the entry-module.ts may be different):

$ ts-node ./src/main.ts --tsConfigJson=./tsconfig.json ./entry-module.ts

If you want to write the results to a JSON file you can do so using --outputJson. Note: make sure the directory already exists!

$ ts-node ./src/main.ts --tsConfigJson=./tsconfig.json --outputJson=./tmp/output.json /entry-module.ts

If you do not want any output to the console you can add the --silent flag.

For best performance, first run yarn build and then use the compiled js version

$ node ./dist/main.js --tsConfigJson=./tsconfig.json --outputJson=./tmp/output.json /entry-module.ts

Example

Given this directory structure (see ./test)

| - entry.ts
| - nothing-exported.ts
| - barrel/
| --- index.ts
| --- partial-export/
| ------ index.ts

The output would be:

{
  "iAmReExported": {
      "originalLocation": "/test/barrel/partial-export/index.ts",
      "reExportPath": [
        "test/entry.ts",
        "test/barrel/index.ts",
        "/test/barrel/partial-export/index.ts"
      ],
      "kind": "VariableStatement"
    },
  "baz": {
      "originalLocation": "test/entry.ts",
      "reExportPath": [
        "test/entry.ts"
      ],
      "kind": ""
    },
    "foo": {
      "originalLocation": "/test/barrel2/inner/foo.ts",
      "reExportPath": [
        "test/entry.ts",
        "/test/barrel2/index.ts",
        "/test/barrel2/inner/index.ts",
        "/test/barrel2/inner/foo.ts"
      ],
      "kind": "VariableStatement"
    },
  "a": {
      "originalLocation": "test/entry.ts",
      "reExportPath": [
        "test/entry.ts"
      ],
      "kind": "VariableStatement"
    },
    "bAlias": {
      "originalLocation": "test/entry.ts",
      "reExportPath": [
        "test/entry.ts"
      ],
      "kind": "VariableStatement"
    }
}