Unit Test an Action's Dependencies

Project

Each example separates the action’s source code under src/ from its unit tests under test/, following the same structure across JavaScript and TypeScript projects.

JavaScript
TypeScript

src

test

Action

The following Pre User Registration action denies signups from a forbidden email domain, requires a full name to be submitted, and otherwise stores that name in user_metadata along with a randomly generated identifier in app_metadata.

JavaScript
TypeScript

mock-dependencies.js

/** @import {Event, PreUserRegistrationAPI} from "@auth0/actions/pre-user-registration/v2" */
const { randomUUID } = require('crypto');

/**
* Handler that will be called during the execution of a PreUserRegistration flow.
*
* @param {Event} event - Details about the context and user that is attempting to register.
* @param {PreUserRegistrationAPI} api - Interface whose methods can be used to change the behavior of the signup.
*/
exports.onExecutePreUserRegistration = async (event, api) => {
  const user = event.user;

  if (user.email?.endsWith('@example.com')) {
    api.access.deny('forbidden', 'Forbidden email domain')
    return;
  }

  const fullName = event.request.body['ulp-fullName'];

  if (fullName === undefined) {
    api.validation.error('invalid_payload', 'Missing full name');
    return;
  }

  api.user.setUserMetadata('full_name', fullName);
  api.user.setAppMetadata('custom_id', randomUUID());
}

mock-dependencies.ts

import type { Event, PreUserRegistrationAPI } from '@auth0/actions/pre-user-registration/v2';
import { randomUUID } from 'crypto';

/**
* Handler that will be called during the execution of a PreUserRegistration flow.
*
* @param {Event} event - Details about the context and user that is attempting to register.
* @param {PreUserRegistrationAPI} api - Interface whose methods can be used to change the behavior of the signup.
*/
exports.onExecutePreUserRegistration = async (event: Event, api: PreUserRegistrationAPI) => {
  const user = event.user;

  if (user.email?.endsWith('@example.com')) {
    api.access.deny('forbidden', 'Forbidden email domain')
    return;
  }

  const fullName = event.request.body['ulp-fullName'];

  if (fullName === undefined) {
    api.validation.error('invalid_payload', 'Missing full name');
    return;
  }

  api.user.setUserMetadata('full_name', fullName);
  api.user.setAppMetadata('custom_id', randomUUID());
};

Unit Test

The unit tests mock the event and api objects to verify that the forbidden domain is denied, that a missing full name triggers a validation error, and that a valid submission stores the full name and a correctly formatted UUID.

Jest

JavaScript
TypeScript

mock-dependencies.spec.js

const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');
const path = require('path');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.js');

describe('onExecutePreUserRegistration', () => {
  let loader;
  let event;
  let api;

  beforeEach(async () => {
    loader = await loadAction(ACTION_PATH);
    [event, api] = getDefaultArguments();
    jest.spyOn(api.access, 'deny');
    jest.spyOn(api.validation, 'error');
    jest.spyOn(api.user, 'setUserMetadata');
    jest.spyOn(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    jest.resetAllMocks();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).toHaveBeenCalledWith('forbidden', 'Forbidden email domain');
    expect(api.validation.error).not.toHaveBeenCalled();
    expect(api.user.setUserMetadata).not.toHaveBeenCalled();
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).not.toHaveBeenCalled();
    expect(api.validation.error).toHaveBeenCalledWith('invalid_payload', 'Missing full name');
    expect(api.user.setUserMetadata).not.toHaveBeenCalled();
    expect(api.user.setAppMetadata).not.toHaveBeenCalled();
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).not.toHaveBeenCalled();
    expect(api.validation.error).not.toHaveBeenCalled();
    expect(api.user.setUserMetadata).toHaveBeenCalledWith('full_name', 'John Doe');
    expect(api.user.setAppMetadata).toHaveBeenCalledWith('custom_id', expect.stringMatching(UUID_V4_PATTERN));
  });
});

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-js-jest",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using Jest",
  "license": "MIT",
  "author": "Auth0",
  "type": "commonjs",
  "main": "module-usage.js",
  "scripts": {
    "test": "jest"
  },
  "devDependencies": {
    "@auth0/actions": "^0.33.0",
    "jest": "^30.4.2"
  },
  "jest": {
    "testEnvironment": "node"
  }
}

Configure jsconfig.json so the actions: import alias resolves to src/:

jsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "commonjs",
    "checkJs": false,
    "baseUrl": ".",
    "paths": {
      "actions:*": [
        "src/*"
      ]
    }
  },
  "include": [
    "src/**/*.js"
  ]
}

mock-dependencies.test.ts

const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');
const path = require('path');
const { compileActionModules } = require('./test-utils/load-compiled-action');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.ts');

describe('onExecutePreUserRegistration', () => {
  let loader: any;
  let event: any;
  let api: any;

  beforeEach(async () => {
    const { compiledActionPath } = compileActionModules(ACTION_PATH);
    loader = await loadAction(compiledActionPath);
    [event, api] = getDefaultArguments();
    jest.spyOn(api.access, 'deny');
    jest.spyOn(api.validation, 'error');
    jest.spyOn(api.user, 'setUserMetadata');
    jest.spyOn(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    jest.resetAllMocks();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).toHaveBeenCalledWith('forbidden', 'Forbidden email domain');
    expect(api.validation.error).not.toHaveBeenCalled();
    expect(api.user.setUserMetadata).not.toHaveBeenCalled();
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).not.toHaveBeenCalled();
    expect(api.validation.error).toHaveBeenCalledWith('invalid_payload', 'Missing full name');
    expect(api.user.setUserMetadata).not.toHaveBeenCalled();
    expect(api.user.setAppMetadata).not.toHaveBeenCalled();
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    expect(api.access.deny).not.toHaveBeenCalled();
    expect(api.validation.error).not.toHaveBeenCalled();
    expect(api.user.setUserMetadata).toHaveBeenCalledWith('full_name', 'John Doe');
    expect(api.user.setAppMetadata).toHaveBeenCalledWith('custom_id', expect.stringMatching(UUID_V4_PATTERN));
  });
});

This test helper compiles the TypeScript action to a temporary file so it can be loaded at runtime:

load-compiled-action.ts

import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';
import * as ts from 'typescript';

export interface ModuleToCompile {
  name: string;
  filename: string;
}

function transpileToTemp(sourcePath: string): string {
  const source = fs.readFileSync(sourcePath, 'utf8');
  const { outputText } = ts.transpileModule(source, {
    compilerOptions: {
      module: ts.ModuleKind.CommonJS,
      target: ts.ScriptTarget.ES2020,
      esModuleInterop: true,
    },
  });

  const tempPath = path.join(
    os.tmpdir(),
    `${path.basename(sourcePath, path.extname(sourcePath))}-${process.pid}-${Date.now()}-${Math.random().toString(36).slice(2)}.js`,
  );
  fs.writeFileSync(tempPath, outputText);
  return tempPath;
}

/**
 * loadAction() (from @auth0/actions/*\/test) reads its target file from disk and
 * runs it via vm.compileFunction, so it never goes through ts-node/Vitest's own
 * TS transform. Action sources (and any actions:-registered modules) must be
 * transpiled to plain JS on disk first.
 */
export function compileActionModules(actionPath: string, modules: ModuleToCompile[] = []) {
  const compiledActionPath = transpileToTemp(actionPath);
  const compiledModules = modules.map((m) => ({
    name: m.name,
    filename: transpileToTemp(m.filename),
  }));

  return { compiledActionPath, compiledModules };
}

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-ts-jest",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using Jest and TypeScript",
  "main": "example.ts",
  "scripts": {
    "test": "jest"
  },
  "author": "Auth0",
  "license": "MIT",
  "devDependencies": {
    "@auth0/actions": "^0.33.0",
    "@types/jest": "^29.5.12",
    "@types/node": "22.14.0",
    "jest": "^29.7.0",
    "ts-jest": "^29.1.2",
    "typescript": "^5.9.2"
  }
}

Configure Jest to compile TypeScript with jest.config.js:

jest.config.js

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
};

Configure tsconfig.json so the actions: import alias resolves to src/:

tsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "NodeNext",
    "moduleResolution": "nodenext",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "outDir": "dist",
    "declaration": true,
    "sourceMap": true,
    "allowJs": true,
    "checkJs": false,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "isolatedModules": true,
    "noEmit": true,
    "paths": {
      "actions:*": [
        "./src/*"
      ]
    }
  },
  "exclude": [
    "node_modules",
    "dist"
  ],
  "include": [
    "**/*.ts"
  ],
  "ts-node": {
    "transpileOnly": true
  }
}

Mocha

JavaScript
TypeScript

mock-dependencies.spec.js

const sinon = require('sinon');
const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');
const path = require('path');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.js');

describe('onExecutePreUserRegistration', () => {
  let loader;
  let event;
  let api;

  beforeEach(async () => {
    loader = await loadAction(ACTION_PATH);
    [event, api] = getDefaultArguments();
    sinon.spy(api.access, 'deny');
    sinon.spy(api.validation, 'error');
    sinon.spy(api.user, 'setUserMetadata');
    sinon.spy(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    sinon.restore();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.calledWith(api.access.deny, 'forbidden', 'Forbidden email domain');
    sinon.assert.notCalled(api.validation.error);
    sinon.assert.notCalled(api.user.setUserMetadata);
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.notCalled(api.access.deny);
    sinon.assert.calledWith(api.validation.error, 'invalid_payload', 'Missing full name');
    sinon.assert.notCalled(api.user.setUserMetadata);
    sinon.assert.notCalled(api.user.setAppMetadata);
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.notCalled(api.access.deny);
    sinon.assert.notCalled(api.validation.error);
    sinon.assert.calledWith(api.user.setUserMetadata, 'full_name', 'John Doe');
    sinon.assert.calledWith(api.user.setAppMetadata, 'custom_id', sinon.match(UUID_V4_PATTERN));
  });
});

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-js-mocha",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using Mocha",
  "license": "MIT",
  "author": "Auth0",
  "type": "commonjs",
  "main": "module-usage.js",
  "scripts": {
    "test": "mocha"
  },
  "devDependencies": {
    "@auth0/actions": "^0.33.0",
    "chai": "^4.5.0",
    "mocha": "^11.0.0",
    "sinon": "^19.0.0"
  }
}

Configure Mocha with .mocharc.json:

.mocharc.json

{
  "spec": "src/**/*.spec.js"
}

Configure jsconfig.json so the actions: import alias resolves to src/:

jsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "commonjs",
    "checkJs": false,
    "baseUrl": ".",
    "paths": {
      "actions:*": [
        "src/*"
      ]
    }
  },
  "include": [
    "src/**/*.js"
  ]
}

mock-dependencies.test.ts

import * as path from 'path';
import sinon from 'sinon';
import { compileActionModules } from './test-utils/load-compiled-action';

const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.ts');

describe('onExecutePreUserRegistration', () => {
  let loader: any;
  let event: any;
  let api: any;

  beforeEach(async () => {
    const { compiledActionPath } = compileActionModules(ACTION_PATH);
    loader = await loadAction(compiledActionPath);
    [event, api] = getDefaultArguments();
    sinon.spy(api.access, 'deny');
    sinon.spy(api.validation, 'error');
    sinon.spy(api.user, 'setUserMetadata');
    sinon.spy(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    sinon.restore();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.calledWith(api.access.deny, 'forbidden', 'Forbidden email domain');
    sinon.assert.notCalled(api.validation.error);
    sinon.assert.notCalled(api.user.setUserMetadata);
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.notCalled(api.access.deny);
    sinon.assert.calledWith(api.validation.error, 'invalid_payload', 'Missing full name');
    sinon.assert.notCalled(api.user.setUserMetadata);
    sinon.assert.notCalled(api.user.setAppMetadata);
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    sinon.assert.notCalled(api.access.deny);
    sinon.assert.notCalled(api.validation.error);
    sinon.assert.calledWith(api.user.setUserMetadata, 'full_name', 'John Doe');
    sinon.assert.calledWith(api.user.setAppMetadata, 'custom_id', sinon.match(UUID_V4_PATTERN));
  });
});

This test helper compiles the TypeScript action to a temporary file so it can be loaded at runtime:

load-compiled-action.ts

import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';
import * as ts from 'typescript';

export interface ModuleToCompile {
  name: string;
  filename: string;
}

function transpileToTemp(sourcePath: string): string {
  const source = fs.readFileSync(sourcePath, 'utf8');
  const { outputText } = ts.transpileModule(source, {
    compilerOptions: {
      module: ts.ModuleKind.CommonJS,
      target: ts.ScriptTarget.ES2020,
      esModuleInterop: true,
    },
  });

  const tempPath = path.join(
    os.tmpdir(),
    `${path.basename(sourcePath, path.extname(sourcePath))}-${process.pid}-${Date.now()}-${Math.random().toString(36).slice(2)}.js`,
  );
  fs.writeFileSync(tempPath, outputText);
  return tempPath;
}

/**
 * loadAction() (from @auth0/actions/*\/test) reads its target file from disk and
 * runs it via vm.compileFunction, so it never goes through ts-node/Vitest's own
 * TS transform. Action sources (and any actions:-registered modules) must be
 * transpiled to plain JS on disk first.
 */
export function compileActionModules(actionPath: string, modules: ModuleToCompile[] = []) {
  const compiledActionPath = transpileToTemp(actionPath);
  const compiledModules = modules.map((m) => ({
    name: m.name,
    filename: transpileToTemp(m.filename),
  }));

  return { compiledActionPath, compiledModules };
}

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-ts-mocha",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using Mocha and TypeScript",
  "license": "MIT",
  "author": "Auth0",
  "scripts": {
    "test": "NODE_OPTIONS=--no-experimental-strip-types mocha"
  },
  "devDependencies": {
    "@auth0/actions": "^0.33.0",
    "@types/chai": "^4.3.16",
    "@types/mocha": "^10.0.6",
    "@types/node": "22.14.0",
    "@types/sinon": "^17.0.3",
    "chai": "^4.5.0",
    "mocha": "^11.0.0",
    "sinon": "^19.0.0",
    "ts-node": "^10.9.2",
    "typescript": "^5.9.2"
  }
}

Configure Mocha with .mocharc.json:

.mocharc.json

{
  "require": "ts-node/register",
  "extension": ["ts"],
  "spec": "src/**/*.test.ts"
}

Configure tsconfig.json so the actions: import alias resolves to src/:

tsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "NodeNext",
    "moduleResolution": "nodenext",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "outDir": "dist",
    "declaration": true,
    "sourceMap": true,
    "allowJs": true,
    "checkJs": false,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "isolatedModules": true,
    "noEmit": true,
    "paths": {
      "actions:*": [
        "./src/*"
      ]
    }
  },
  "exclude": [
    "node_modules",
    "dist"
  ],
  "include": [
    "**/*.ts"
  ],
  "ts-node": {
    "transpileOnly": true
  }
}

Node.js Test Runner

JavaScript
TypeScript

mock-dependencies.spec.js

const assert = require('node:assert');
const { describe, it, beforeEach, afterEach, mock } = require('node:test');
const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');
const path = require('path');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.js');

describe('onExecutePreUserRegistration', () => {
  let loader;
  let event;
  let api;

  beforeEach(async () => {
    loader = await loadAction(ACTION_PATH);
    [event, api] = getDefaultArguments();
    mock.method(api.access, 'deny');
    mock.method(api.validation, 'error');
    mock.method(api.user, 'setUserMetadata');
    mock.method(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    mock.reset();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.deepEqual(api.access.deny.mock.calls[0].arguments, ['forbidden', 'Forbidden email domain']);
    assert.strictEqual(api.validation.error.mock.calls.length, 0);
    assert.strictEqual(api.user.setUserMetadata.mock.calls.length, 0);
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.strictEqual(api.access.deny.mock.calls.length, 0);
    assert.deepEqual(api.validation.error.mock.calls[0].arguments, ['invalid_payload', 'Missing full name']);
    assert.strictEqual(api.user.setUserMetadata.mock.calls.length, 0);
    assert.strictEqual(api.user.setAppMetadata.mock.calls.length, 0);
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.strictEqual(api.access.deny.mock.calls.length, 0);
    assert.strictEqual(api.validation.error.mock.calls.length, 0);
    assert.deepEqual(api.user.setUserMetadata.mock.calls[0].arguments, ['full_name', 'John Doe']);

    const appMetadataCall = api.user.setAppMetadata.mock.calls[0];
    assert.strictEqual(appMetadataCall.arguments[0], 'custom_id');
    assert.match(appMetadataCall.arguments[1], UUID_V4_PATTERN);
  });
});

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-js-node-test",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using the Node.js built-in test runner",
  "license": "MIT",
  "author": "Auth0",
  "type": "commonjs",
  "main": "module-usage.js",
  "scripts": {
    "test": "node --test src/*.spec.js"
  },
  "devDependencies": {
    "@auth0/actions": "^0.33.0"
  }
}

Configure jsconfig.json so the actions: import alias resolves to src/:

jsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "commonjs",
    "checkJs": false,
    "baseUrl": ".",
    "paths": {
      "actions:*": [
        "src/*"
      ]
    }
  },
  "include": [
    "src/**/*.js"
  ]
}

mock-dependencies.test.ts

const assert = require('node:assert');
const { describe, it, beforeEach, afterEach, mock } = require('node:test');
const { getDefaultArguments, loadAction } = require('@auth0/actions/pre-user-registration/v2/test');
const path = require('path');
const { compileActionModules } = require('./test-utils/load-compiled-action.ts');

const UUID_V4_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

const DIRNAME = path.dirname('../');
const ACTION_PATH = path.resolve(DIRNAME, './src/mock-dependencies.ts');

describe('onExecutePreUserRegistration', () => {
  let loader;
  let event;
  let api;

  beforeEach(async () => {
    const { compiledActionPath } = compileActionModules(ACTION_PATH);
    loader = await loadAction(compiledActionPath);
    [event, api] = getDefaultArguments();
    mock.method(api.access, 'deny');
    mock.method(api.validation, 'error');
    mock.method(api.user, 'setUserMetadata');
    mock.method(api.user, 'setAppMetadata');
  });

  afterEach(() => {
    mock.reset();
  });

  it('forbids email domain', async () => {
    event.user.email = 'johndoe@example.com';

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.deepEqual(api.access.deny.mock.calls[0].arguments, ['forbidden', 'Forbidden email domain']);
    assert.strictEqual(api.validation.error.mock.calls.length, 0);
    assert.strictEqual(api.user.setUserMetadata.mock.calls.length, 0);
  });

  it('allows email domain without full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {};

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.strictEqual(api.access.deny.mock.calls.length, 0);
    assert.deepEqual(api.validation.error.mock.calls[0].arguments, ['invalid_payload', 'Missing full name']);
    assert.strictEqual(api.user.setUserMetadata.mock.calls.length, 0);
    assert.strictEqual(api.user.setAppMetadata.mock.calls.length, 0);
  });

  it('allows email domain with full name', async () => {
    event.user.email = 'johndoe@test.com';
    event.request.body = {
      'ulp-fullName': 'John Doe',
    };

    await loader.execute('onExecutePreUserRegistration', event, api);

    assert.strictEqual(api.access.deny.mock.calls.length, 0);
    assert.strictEqual(api.validation.error.mock.calls.length, 0);
    assert.deepEqual(api.user.setUserMetadata.mock.calls[0].arguments, ['full_name', 'John Doe']);

    const appMetadataCall = api.user.setAppMetadata.mock.calls[0];
    assert.strictEqual(appMetadataCall.arguments[0], 'custom_id');
    assert.match(appMetadataCall.arguments[1], UUID_V4_PATTERN);
  });
});

This test helper compiles the TypeScript action to a temporary file so it can be loaded at runtime:

load-compiled-action.ts

const fs = require('fs');
const os = require('os');
const path = require('path');
const ts = require('typescript');

interface ModuleToCompile {
  name: string;
  filename: string;
}

function transpileToTemp(sourcePath: string): string {
  const source = fs.readFileSync(sourcePath, 'utf8');
  const { outputText } = ts.transpileModule(source, {
    compilerOptions: {
      module: ts.ModuleKind.CommonJS,
      target: ts.ScriptTarget.ES2020,
      esModuleInterop: true,
    },
  });

  const tempPath = path.join(
    os.tmpdir(),
    `${path.basename(sourcePath, path.extname(sourcePath))}-${process.pid}-${Date.now()}-${Math.random().toString(36).slice(2)}.js`,
  );
  fs.writeFileSync(tempPath, outputText);
  return tempPath;
}

/**
 * loadAction() (from @auth0/actions/*\/test) reads its target file from disk and
 * runs it via vm.compileFunction, so it never goes through node's native TS type
 * stripping. Action sources (and any actions:-registered modules) must be
 * transpiled to plain JS on disk first.
 */
exports.compileActionModules = function compileActionModules(actionPath: string, modules: ModuleToCompile[] = []) {
  const compiledActionPath = transpileToTemp(actionPath);
  const compiledModules = modules.map((m: ModuleToCompile) => ({
    name: m.name,
    filename: transpileToTemp(m.filename),
  }));

  return { compiledActionPath, compiledModules };
};

Add the test dependencies to package.json:

package.json

{
  "name": "actions-npm-example-ts-node-test",
  "version": "1.0.0",
  "description": "Auth0 Actions unit testing example using the Node.js built-in test runner and TypeScript",
  "license": "MIT",
  "author": "Auth0",
  "scripts": {
    "test": "node --test src/*.test.ts"
  },
  "devDependencies": {
    "@auth0/actions": "^0.33.0",
    "@types/node": "22.14.0",
    "typescript": "^5.9.2"
  }
}

Configure tsconfig.json so the actions: import alias resolves to src/:

tsconfig.json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "NodeNext",
    "moduleResolution": "nodenext",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "outDir": "dist",
    "declaration": true,
    "sourceMap": true,
    "allowJs": true,
    "checkJs": false,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "isolatedModules": true,
    "noEmit": true,
    "paths": {
      "actions:*": [
        "./src/*"
      ]
    }
  },
  "exclude": [
    "node_modules",
    "dist"
  ],
  "include": [
    "**/*.ts"
  ],
  "ts-node": {
    "transpileOnly": true
  }
}

Brand Customization

Code Customization

Third-Party Customization

Unit Test an Action's Dependencies

Project

Action

Unit Test

​Project

​Action

​Unit Test

Project

Action

Unit Test