[FEAT] : Product Categories Listing API Endpoint

[VictorIborTech]

Description

Create an API endpoint to retrieve all product categories, providing essential information for product navigation and filtering.

Acceptance Criteria

• The API endpoint (/api/v1/products/categories) correctly handles the GET request and returns the expected response format.
• The endpoint returns a complete list of all product categories in the system.
• The response includes category ID, name, description, and slug for each category.
• The endpoint response time is under 500ms for up to 1000 categories.
• Optional query parameters (limit, offset, parent_id) are properly handled if implemented.
• Proper error handling is in place for invalid requests or server errors.

Purpose

To provide clients with a comprehensive list of product categories, enabling effective navigation, filtering, and organization of products.

Requirements

• [ ] Create the API endpoint for retrieving product categories.
• [ ] Implement efficient database querying to fetch category data.
• [ ] Include proper indexing on the categories table for optimal performance.
• [ ] Implement optional query parameters for advanced use cases (limit, offset, parent_id).
• [ ] Ensure proper error handling for invalid requests or server-side issues.
• [ ] Implement caching mechanism to improve response times for frequent requests.

Endpoint

• Method: GET

  GET /api/v1/products/categories

Responses:

Success

• Status Code: 200 OK

{
  "status_code": 200,
  "categories": [
    {
      "id": 1,
      "name": "Electronics",
      "description": "Electronic devices and accessories",
      "slug": "electronics",
      "parent_id": null
    },
    {
      "id": 2,
      "name": "Clothing",
      "description": "Apparel and fashion items",
      "slug": "clothing",
      "parent_id": null
    }

  ]
}

Error

400 Bad Request: Invalid query parameters

{
  "status_code": 400,
  "error": {
    "code": "INVALID_QUERY_PARAMETER",
    "message": "The provided query parameter is invalid.",
    "details": {
      "invalid_parameter": "limit",
      "reason": "Must be a positive integer"
    }
  }
}

500 Internal Server Error: Server-side error

{
 "status_code": 500,
 "error": {
    "code": "INTERNAL_SERVER_ERROR",
    "message": "An unexpected error occurred while processing your request.",
    "details": {
      "support_email": "support@example.com"
    }
  }
}

Expected Outcome

• Clients can successfully retrieve a list of all product categories.
• The endpoint provides accurate and up-to-date category information.
• The system handles errors gracefully, providing clear messages to the client.
• The feature performs well, with quick response times even for large category lists.

Additional Information

• Consider implementing a caching mechanism to improve performance for frequent requests.
• Consider future scalability if the number of categories is expected to grow significantly.

Testing

• Perform manual tests to verify the API endpoint response structure and data accuracy.
• Write unit tests for the category retrieval logic.
• Write integration tests to ensure proper database interaction and response formatting.
• Conduct performance testing to verify response times under various loads.
• Test error scenarios to ensure proper error handling and messaging.

[VictorIborTech]

Copied and Duplicated from #https://github.com/hngprojects/hng_boilerplate_nestjs/issues/257