README.md

Node Testing Library

Get started

npm i -D @osmoscraft/node-testing-library

Create run-test.ts in your project root with the following content:

import { getTests, runTests } from "@osmoscraft/node-testing-library";

async function run() {
  const tests = await getTests("src", /\.test\.ts$/);
  runTests(tests);
}

run();

Update package.json with the following scripts to run tests

  "scripts": {
    "test": "ts-node-dev --quiet --transpile-only run-test.ts",
    "test:watch": "ts-node-dev --respawn --watch --transpile-only run-test.ts",
  },

Write your first test in src/hello-world.test.ts

import { describe, expect, it } from "@osmoscraft/node-testing-library";

describe("hello world", () => {
  it("should pass", async () => {
    await expect("hello").toEqual("hello");
  });
});

Please make sure to use await in frontend of each expect or the error reporting may not be able to surface all failed tests

API

import { describe, expect, it, beforeEach, afterEach, beforeAll, afterAll } from "@osmoscraft/node-testing-library";

describe("hello world", () => {
  beforeAll(async () => {
    // do something before all specs
  });
  beforeEach(async () => {
    // do something before each spec
  });
  it("spec name", async () => {
    // simple assertion
    await expect("hello").toEqual("hello");
    
    // simple error
    await expect(() => throw new Error()).toThrow();
    
    // negation
    await expect(true).not.toEqual(false);
    await expect(() => {}).not.toThrow();
  });
  afterEach(async () => {
    // do something after each specs
  });
  afterAll(async () => {
    // do something after all specs
  });
});

TypeScript configuration

This library relies on ts-node-dev to compile TypeScript to JavavScript only the fly. Since the JavaScript output will be executed in a Node.js environment, your tsconfig.json should produce code that is compatible with Node.js. If your existing tsconfig.json produces code using ESNext module, you will need to specific a separate tsconfig.test.json like this:

{
  "compilerOptions": {
    "target": "es2019",
    "moduleResolution": "node",
    "module": "CommonJS",
    "importsNotUsedAsValues": "error",
    "strict": true,
    "esModuleInterop": true,
    "outDir": "dist"
  }
}

and consume it in your package.json test script:

  "scripts": {
    "test": "ts-node-dev --project tsconfig.test.json --quiet --transpile-only run-test.ts",
    "test:watch": "ts-node-dev --project tsconfig.test.json --respawn --watch --transpile-only run-test.ts",
  },