Custom Nx Generator with Tests

Create a custom Nx generator that adds a new library to a workspace and write comprehensive tests for it using Nx testing utilities.

Requirements

Generator Implementation

Implement a generator named library that:

• Accepts a name option (string, required) for the library name
• Accepts a directory option (string, optional) for the library location
• Creates a new library project in the workspace at the specified or default location
• Adds a basic TypeScript file to the library with an exported function
• Updates the workspace configuration to include the new library project

Test Suite

Write tests for the generator that:

• Verify the generator creates the expected files in the virtual tree
• Verify the library name is correctly used in generated files
• Verify the workspace configuration is updated with the new project
• Test both with and without the optional directory parameter
• Use a mock project graph to verify dependencies if any are created

Implementation Details

The generator should create:

• A src/index.ts file with a basic exported function
• A project.json file with appropriate configuration
• Update the workspace tree accordingly

Test Cases

• It creates a library with the specified name in the default location @test
• It creates a library in a custom directory when directory option is provided @test
• It generates the expected index.ts file with correct exports @test
• It updates the project configuration correctly @test

Implementation

@generates

API

import { Tree } from '@nx/devkit';

export interface LibraryGeneratorSchema {
  name: string;
  directory?: string;
}

export async function libraryGenerator(
  tree: Tree,
  options: LibraryGeneratorSchema
): Promise<void>;

Dependencies { .dependencies }

@nx/devkit { .dependency }

Provides tree manipulation, configuration utilities, and testing utilities for Nx plugin development.