Assert Apex: Effortless Chai Assertion Generation

Generate Chai assertions effortlessly from JSON objects or API response payloads. Simplify testing by letting assert-apex handle repetitive assertion generation tasks.

✨ Features

• Automatically generate Chai assertions from any JSON structure.
• Supports deep nested objects and arrays.
• Configurable maximum depth for traversing nested structures.
• Intelligent type-checking with detailed validation messages.
• Reduces boilerplate code in tests and speeds up development.

📦 Installation

Install the library using npm:

npm install assert-apex

🚀 Quick Start

// Import the library
const AssertApex = require('assert-apex');

// Initialize the generator with optional configurations
const generator = new AssertApex({
  maxDepth: 10 // Maximum depth to traverse for nested objects (default: 10)
});

// Example API response or JSON object
const response = {
  userId: 1,
  title: "Test",
  completed: false
};

// Generate Chai assertions
const assertions = generator.generate(response);

// Output the generated assertions
console.log(assertions);

Output:

expect(response.userId, "userId should exist").to.exist;
expect(response.userId, "userId should be a number").to.be.a('number');
expect(response.title, "title should exist").to.exist;
expect(response.title, "title should be a string").to.be.a('string');
expect(response.completed, "completed should exist").to.exist;
expect(response.completed, "completed should be a boolean").to.be.a('boolean');

🛠 Configuration Options

You can configure the generator to suit your needs by passing an options object to the constructor:

| Option | Type | Default | Description | |---------------|------------|-------------|---------------------------------------------------------------------------------| | maxDepth | number | 10 | Specifies the maximum depth to traverse nested objects and arrays. |

💡 How It Works

The library intelligently traverses your JSON structure and generates:

• Existence checks: Ensures every key in the object exists.
• Type assertions: Validates data types for all keys.
• Structure validation: Handles nested objects, arrays, and mixed types.

Supported Assertions

• Existence: to.exist, to.be.null
• Type: to.be.a('string'), to.be.an('array')
• Structure: Validates non-emptiness and consistent array types.

🖋 Example Scenarios

1. Nested Object

const response = {
  user: {
    id: 42,
    profile: {
      name: "John Doe",
      age: 30
    }
  }
};

console.log(generator.generate(response));

Output:

expect(response.user, "user should exist").to.exist;
expect(response.user, "user should be an object").to.be.an('object');
expect(response.user.id, "id should exist").to.exist;
expect(response.user.id, "id should be a number").to.be.a('number');
expect(response.user.profile, "profile should exist").to.exist;
expect(response.user.profile, "profile should be an object").to.be.an('object');
expect(response.user.profile.name, "name should exist").to.exist;
expect(response.user.profile.name, "name should be a string").to.be.a('string');
expect(response.user.profile.age, "age should exist").to.exist;
expect(response.user.profile.age, "age should be a number").to.be.a('number');

2. Arrays with Mixed Types

const response = {
  items: [1, "string", { key: "value" }]
};

console.log(generator.generate(response));

Output:

expect(response.items, "items should exist").to.exist;
expect(response.items, "items should be an array").to.be.an('array');
expect(response.items[0], "items[0] should be a number").to.be.a('number');
expect(response.items[1], "items[1] should be a string").to.be.a('string');
expect(response.items[2], "items[2] should be an object").to.be.an('object');

🎨 Advanced Customization

• Modify the maxDepth option for large or complex JSON structures.
• Add support for custom validation logic by extending the addAssertion method.

🤝 Contributing

We welcome contributions! Check out the contribution guidelines for more details.

📄 License

This project is licensed under the MIT License. See the LICENSE file for details.

💬 Support

For questions or issues, please open an issue on GitHub.