Middleware: Map-based response variation

Our mock server leverages Rhai scripts to handle dynamic HTTP responses.

Beyond returning a simple string representing a file path, it supports returning map-type values, enabling even greater flexibility in crafting responses. It enables us to return JSON or plain text bodies, providing a dynamic and powerful way to mock complex API behaviors.

Supported Map Keys

The process for generating map-based response is straightforward. You can determine the behavior by specifying a map key: either of file_path, json, text. Any of the associated value should be string.

file_path

The associated value will be treated as a file path. (The same bahavior when a string-type value is returned instead of map)

Example

return #{ "file_path": "some-dir/file.ext" };

json

The server will send an application/json response. The associated value will be used directly as the HTTP response body. This allows you to generate dynamic JSON responses within your Rhai script.

Examples

return #{ "json": "{ \"myjsonkey\": \"myjsonvalue\" }" };

Note: Remember to properly escape double quotes within your JSON string.

let json_str = "{ \"greetings\": \"Hello, world.\" }";

// debug print:
print(url_path);

if url_path == "/middleware-test/map/json" {
    return #{ "json": json_str };
}

text

The server will send a text/plain; utf-8 response.

Example

return #{ "text": "Hello, this is a plain text response !" };