TypeScript API Controller Implementation

TypeScript
export const getResourceController = async (
  id: string,
  qsParams: ResourceQueryParams,
): Promise<AxiosResponse<App.Pagination<Resource>, any>> => {
  const qs = getQueryStringFromRecord(qsParams);
  const url = `/api/resource/${id}?${qs}`;
  
  const instance = genRequestInstance();
  
  try {
    const response = await instance.get(url);
    return response;
  } catch (error) {
    console.error('Erro na requisição:', error);
    return Promise.reject(error);
  }
};

Progress:

• Define function signature with proper TypeScript types
• Extract query string parameters
• Construct URL with path parameters and query string
• Create HTTP client instance
• Execute GET request with error handling
• Return typed response

Step 1: Define Function Signature

TypeScript
export const getResourceController = async (
  // Path parameters
  resourceId: Resource.Id,
  // Query parameters
  qsParams: Resource.QueryStringParams,
): Promise<AxiosResponse<ResponseType, any>> => {

Step 2: Build URL

TypeScript
const qs = getQueryStringFromRecord(qsParams);
const url = `/api/resource/${resourceId}?${qs}`;

Step 3: Execute Request

TypeScript
const instance = genRequestInstance();
try {
  const response = await instance.get(url);
  return response;
} catch (error) {
  console.error('Erro na requisição:', error);
  return Promise.reject(error);
}

Example 1: Simple Resource Controller Input: Users list with pagination

TypeScript
export const getUsersController = async (
  qsParams: User.QueryStringParams,
): Promise<AxiosResponse<App.Pagination<User.User>, any>> => {
  const qs = getQueryStringFromRecord(qsParams);
  const url = `/api/users?${qs}`;
  
  const instance = genRequestInstance();
  
  try {
    const response = await instance.get(url);
    return response;
  } catch (error) {
    console.error('Erro na requisição:', error);
    return Promise.reject(error);
  }
};

Example 2: Nested Resource Controller Input: Orders for specific customer

TypeScript
export const getCustomerOrdersController = async (
  customerId: Customer.Id,
  qsParams: Order.QueryStringParams,
): Promise<AxiosResponse<App.Pagination<Order.Order>, any>> => {
  const qs = getQueryStringFromRecord(qsParams);
  const url = `/api/customers/${customerId}/orders?${qs}`;
  
  const instance = genRequestInstance();
  
  try {
    const response = await instance.get(url);
    return response;
  } catch (error) {
    console.error('Erro na requisição:', error);
    return Promise.reject(error);
  }
};

Example 3: Multiple Path Parameters Input: Product variants for specific category and brand

TypeScript
export const getProductVariantsController = async (
  categoryId: Category.Id,
  brandId: Brand.Id,
  qsParams: Product.VariantQueryParams,
): Promise<AxiosResponse<App.Pagination<Product.Variant>, any>> => {
  const qs = getQueryStringFromRecord(qsParams);
  const url = `/api/categories/${categoryId}/brands/${brandId}/variants?${qs}`;
  
  const instance = genRequestInstance();
  
  try {
    const response = await instance.get(url);
    return response;
  } catch (error) {
    console.error('Erro na requisição:', error);
    return Promise.reject(error);
  }
};

• Use descriptive function names: Include the resource and action (getUsersController, not getController)
• Type everything: Path parameters, query parameters, and response types
• Follow URL structure: /api/{resource}/{id}/{subresource}
• Consistent error handling: Log error and reject promise
• Use const assertions: For URL building to prevent mutations
• Export const functions: Better for tree-shaking than default exports

• Missing type definitions: Always define interfaces for query params and response types
• Hardcoded URLs: Use constants or environment variables for base URLs
• Swallowing errors: Don't catch errors without re-throwing or proper handling
• Missing await: Controllers are async, ensure proper await usage
• Inconsistent naming: Stick to {action}{Resource}Controller pattern
• No validation: Consider validating query parameters before sending request
• Memory leaks: Don't store axios instances in global scope without cleanup