Add DuplexJsonRpcEngine

Author: rekmarks

src/DuplexJsonRpcEngine.ts

@@ -0,0 +1,162 @@
+import {
+  isJsonRpcRequest,
+  JsonRpcNotification,
+  JsonRpcRequest,
+  JsonRpcResponse,
+} from '@metamask/utils';
+import {
+  JsonRpcEngine,
+  JsonRpcMiddleware,
+  JsonRpcNotificationHandler,
+} from './JsonRpcEngine';
+
+type HandleArgument =
+  | JsonRpcRequest<unknown>
+  | JsonRpcNotification<unknown>
+  | (JsonRpcRequest<unknown> | JsonRpcNotification<unknown>)[];
+
+interface DuplexJsonRpcEngineArgs {
+  receiverNotificationHandler: JsonRpcNotificationHandler<unknown>;
+  senderNotificationHandler: JsonRpcNotificationHandler<unknown>;
+}
+
+export class DuplexJsonRpcEngine {
+  readonly #receiver: JsonRpcEngine;
+
+  readonly #sender: JsonRpcEngine;
+
+  get receiver(): JsonRpcEngine {
+    return this.#receiver;
+  }
+
+  get sender(): JsonRpcEngine {
+    return this.#sender;
+  }
+
+  constructor({
+    receiverNotificationHandler,
+    senderNotificationHandler,
+  }: DuplexJsonRpcEngineArgs) {
+    this.#receiver = new JsonRpcEngine({
+      notificationHandler: receiverNotificationHandler,
+    });
+
+    this.#sender = new JsonRpcEngine({
+      notificationHandler: senderNotificationHandler,
+    });
+  }
+
+  /**
+   * Add a middleware function to the receiving middleware stack.
+   *
+   * @param middleware - The middleware function to add.
+   */
+  pushReceiverMiddleware(
+    middleware: JsonRpcMiddleware<unknown, unknown>,
+  ): void {
+    this.#receiver.push(middleware as JsonRpcMiddleware<unknown, unknown>);
+  }
+
+  /**
+   * Add a middleware function to the sending middleware stack.
+   *
+   * @param middleware - The middleware function to add.
+   */
+  pushSenderMiddleware(middleware: JsonRpcMiddleware<unknown, unknown>): void {
+    this.#sender.push(middleware as JsonRpcMiddleware<unknown, unknown>);
+  }
+
+  /**
+   * Returns the receiving pipeline as a middleware function that can be pushed
+   * to other engines.
+   *
+   * @returns The receiving pipeline as a middleware function.
+   */
+  receiverAsMiddleware(): JsonRpcMiddleware<unknown, unknown> {
+    return this.#receiver.asMiddleware();
+  }
+
+  /**
+   * Returns the sending pipeline as a middleware function that can be pushed
+   * to other engines.
+   *
+   * @returns The sending pipeline as a middleware function.
+   */
+  senderAsMiddleware(): JsonRpcMiddleware<unknown, unknown> {
+    return this.#sender.asMiddleware();
+  }
+
+  /**
+   * Receive a JSON-RPC request, and return a response.
+   *
+   * @param request - The JSON-RPC request to receive.
+   * @returns The JSON-RPC response.
+   */
+  receive<Params, Result>(
+    request: JsonRpcRequest<Params>,
+  ): Promise<JsonRpcResponse<Result>>;
+
+  /**
+   * Receive a JSON-RPC notification.
+   *
+   * @param notification - The notification to receive.
+   */
+  receive<Params>(notification: JsonRpcNotification<Params>): Promise<void>;
+
+  /**
+   * Receive an array of JSON-RPC requests and/or notifications, and return an
+   * array of responses to any included requests.
+   *
+   * @param request - The JSON-RPC requests to receive.
+   * @returns An array of JSON-RPC responses.
+   */
+  receive<Params, Result>(
+    requests: (JsonRpcRequest<Params> | JsonRpcNotification<Params>)[],
+  ): Promise<JsonRpcResponse<Result>[]>;
+
+  async receive(argument: HandleArgument) {
+    if (Array.isArray(argument)) {
+      return this.#receiver.handle(argument);
+    } else if (isJsonRpcRequest(argument)) {
+      return this.#receiver.handle(argument);
+    }
+    return this.#receiver.handle(argument);
+  }
+
+  /**
+   * Send a JSON-RPC request, and receive a response.
+   *
+   * @param request - The JSON-RPC request to send.
+   * @returns The JSON-RPC response.
+   */
+  send<Params, Result>(
+    request: JsonRpcRequest<Params>,
+  ): Promise<JsonRpcResponse<Result>>;
+
+  /**
+   * Send a JSON-RPC notification.
+   *
+   * @param notification - The notification to send.
+   */
+  send<Params>(notification: JsonRpcNotification<Params>): Promise<void>;
+
+  /**
+   * Send an array of JSON-RPC requests and/or notifications, and receive an
+   * array of responses to any included requests.
+   *
+   * @param request - The JSON-RPC requests to send.
+   * @returns An array of JSON-RPC responses.
+   */
+  send<Params, Result>(
+    requests: (JsonRpcRequest<Params> | JsonRpcNotification<Params>)[],
+  ): Promise<JsonRpcResponse<Result>[]>;
+
+  async send(argument: HandleArgument) {
+    if (Array.isArray(argument)) {
+      return this.#sender.handle(argument);
+    } else if (isJsonRpcRequest(argument)) {
+      return this.#sender.handle(argument);
+    }
+    return this.#sender.handle(argument);
+  }
+}