rest-grpc-handler

rest-grpc-handler is a versatile mock server designed for both Rest and gRPC calls, facilitating the testing of applications by simulating backend services. This tool automatically generates a structured mock environment based on your configuration, making it an essential asset for developers looking to streamline their testing process.

Installation

To install rest-grpc-handler, run the following command:

npm i rest-grpc-handler

Getting Started

To start the server, execute:

npx rest-grpc-handler

Upon launch, rest-grpc-handler checks for the presence of specific configuration files and folders. If they are not found, it creates the following structure within your project:

requests/ 
    grpc/ 
    http-proxy/ 
rest_grpc_handler/ 
    protos/ 
    config.json 
case.json

Configuration

• Protos Folder: Place your .proto files in the rest_grpc_handler/protos directory. These files are used by the gRPC server to construct the methods for the calls.

• config.json: Configures the ports for the servers and enables or disables them. Default configuration:

{
  "grpc": {"port": 50051, "enabled": true},
  "http": {"port": 50052, "enabled": true}
}

• case.json: Determines the naming convention for mock storage directories based on the case property. Default content:

{"case":"default"}

Mocks Organization

Mocks are organized under the requests/ directory, divided into grpc and http-proxy for respective call types. The server dynamically creates and stores mocks based on the case.json configuration and the request paths.

Example

For a GET request to http://my_api_gateway/products/list?id=2, and with case.json set to {"case":"view_the_second_product_page"}, the following structure is generated:

./requests/
    http-proxy/
        view_the_second_product_page/
            products_list?id=2/
                get/
                    0.json

The 0.json file is automatically generated upon a call if no mock exists yet. If your application makes multiple calls to the same resource, a new .json file is created for each call. For instance, if your application makes 3 calls to the same resource mentioned in the example, the directory ./requests/http-proxy/view_the_second_product_page/products_list?id=2/get/ will contain the files 0.json, 1.json, 2.json, etc., sequentially.

Request Counter Reset

The rest-grpc-handler module internally maintains a request counter for each resource accessed while the server is running. This feature enables it to determine whether a call to a specific resource is the first or a subsequent one.

To reset the request counter, send a GET request to:

http://localhost:50052/requestCounter/reset

This counter is stored in memory, so it is reset to zero whenever the server is restarted.

Mock Files Structure

• REST Mocks: Control the status, headers, and body of the response.

{
  "status": 200,
  "headers": {},
  "body": {}
}

• gRPC Mocks: Simpler structure, primarily containing the message returned by the called methods.

{"data":[{"key":"MY_KEY","value":"MY_VALUE"}]}

rest-grpc-handler aims to provide a mock for any call made, eliminating the need for prior resource mapping. This flexibility allows for a wide range of testing scenarios, making it a valuable tool for development and testing teams.