generate-unit-test

Rule: Unit Test Generation

Goal

To guide an AI assistant in generating comprehensive unit tests based on a previously created function analysis document. The tests should cover all scenarios identified in the analysis and follow testing best practices.

Prerequisites

• A function analysis document (created by extract-functions.mdc)
• Source code file to be tested
• Knowledge of the testing framework being used (Jest, Vitest, etc.)

Process

1. Load Analysis Document: Read and understand the function analysis document
2. Identify Testing Framework: Determine the testing framework and setup requirements
3. Generate Test Structure: Create the basic test file structure with imports and setup
4. Generate Function Tests: Create comprehensive tests for each function based on the analysis
5. Add Mock Implementations: Generate necessary mocks and test utilities
6. Save Test File: Save as [source-filename].test.[extension] alongside the source file

Test Generation Guidelines

Test File Structure

// Imports and setup
import { function1, function2 } from './source-file';
import { jest } from '@jest/globals'; // or equivalent for your framework

// Mock setup (if needed)
jest.mock('external-dependency');

// Test setup and utilities
const mockSetup = () => { /* setup code */ };

// Test suites grouped by function
describe('FunctionName', () => {
  // Tests for each function
});

For Each Function Generate:

1. Basic Test Structure

describe('[FunctionName]', () => {
  // Setup
  beforeEach(() => {
    // Reset mocks, setup test data
  });

  // Test cases here
});

2. Happy Path Tests

• Test normal, expected usage
• Test with typical input values
• Verify expected return values and behavior

3. Edge Case Tests

• Boundary values (empty strings, zero, null, undefined)
• Maximum/minimum values
• Special characters or unusual but valid inputs

4. Error Handling Tests

• Invalid inputs
• Error throwing scenarios
• Error message validation