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RxJS Ninja Template Library

This repository is a Github Template for generating Typescript libraries for the web with UMD and ESM compilation.

It's build using the Nx monorepo approach and is set up to allow for libraries to be developed with their own public API and compiled for use in any ECMAScript environment including node, framework or VanillaJS approaches.

Library Setup

Included in this repo is the Example Library - a small RxJS library that exports a fizzbuzz operator and an Observable fromFizzbuzz sequence generator.

To set this up I used @nrwl/node to generate the library:

> nx g @nrwl/node:lib example-lib --directory=rxjs --publishable --importPath=@rxjs-ninja/example-lib

By default this sets up a node-compatible library using CommonJS, but this can cause issues with modern frameworks for the web.

Here the builder options in the project are replaced in workspace.json to use the @nrwl/web builder with Babel and Rollup, and add support for the readme and changelog:

  "build": {
    "builder": "@nrwl/web:package",
    "options": {
      "globals": [
          "moduleId": "rxjs",
          "global": "rxjs"
          "moduleId": "rxjs/operators",
          "global": "rxjs.operators"
          "moduleId": "@rxjs-ninja/rxjs-utility",
          "global": "RxjsUtility"
      "outputPath": "dist/libs/rxjs/example-lib",
      "tsConfig": "libs/rxjs/example-lib/tsconfig.lib.json",
      "project": "libs/rxjs/example-lib/package.json",
      "entryFile": "libs/rxjs/example-lib/src/index.ts",
      "external": ["rxjs", "@rxjs-ninja/rxjs-utility"],
      "babelConfig": "@nrwl/web/babel",
      "assets": [
          "glob": "",
          "input": "libs/rxjs/example-lib/.",
          "output": "."
          "glob": "",
          "input": "libs/rxjs/example-lib/.",
          "output": "."

This also needs the babel.config.json and .babelrc files.

In the library tsconfig.lib.json the module property needs to be changed from commonjs to es2015.

See the example folder for full details of the setup.

Now when running nx build rxjs-example-lib a version of the library is built that can be used in any environment including the web.

Running unit tests

The unit tests in the library use marble diagrams to provide the data to the operators. Jest is integrated using rxjs-marbles and provides full code coverage too.

Run nx test rxjs-example-lib --codeCoverage to execute the unit tests via Jest.

Run nx affected:test to execute the unit tests affected by a change.

Generating Docs

Run npm run docs to generate docs using Typedoc and output to the doc folder.

This also uses typedoc-plugin-external-module-name to provide better support for a module layout in documentation

Github Action Pipeline

In the .github folder there are some YAML and Bash scripts provided that I have developed for working with NX Monorepos and publishing libraries with changelogs and documentation.

Using the UMD Library

When the library is published it can be used as a UMD library using unpkg - here is an example of RxJS with two libraries from RxJS Ninja on a basic HTML page. A StackBlitz Example is available.

<!DOCTYPE html>

    <div>Random Number: <span class="output"></span></div>

  <script src=""></script>
  <script src=""></script>
  <script src=""></script>

  <script module>
    const output = document.querySelector('.output');

    const { tap } = rxjs.operators;
    const { fromRandom } = RxjsRandom;
    const { roundTo } = RxjsNumber;
    fromRandom(0, 1, 1000)
        tap((value) => (output.innerHTML = value)),

Further help

Visit the Nx Documentation to learn more.


A starter project that is set up using NX Monorepo to create new Typescript libraries for the web








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