Implement sending messages to server add-on

Reviewed By: mweststrate

Differential Revision: D34073403

fbshipit-source-id: eacd73811b436f2b5c4255a83d8eb09367a96a67

desktop/flipper-common/src/server-types.tsx

@@ -580,6 +580,8 @@ export type ExecuteMessage = {
     params?: unknown;
   };
 };
+
+// TODO: Could we merge it with ClientResponseType?
 export type ResponseMessage =
   | {
       id: number;

desktop/flipper-server-core/src/plugins/ServerAddOn.tsx

@@ -8,12 +8,15 @@
  */
 
 import assert from 'assert';
-import {ClientResponseType, ExecuteMessage} from 'flipper-common';
 import {assertNotNull} from '../comms/Utilities';
+import {ServerAddOnDesktopToModuleConnection} from './ServerAddOnDesktopToModuleConnection';
+import {ServerAddOnModuleToDesktopConnection} from './ServerAddOnModuleToDesktopConnection';
 
 type ServerAddOnCleanup = () => Promise<void>;
 interface ServerAddOnModule {
-  serverAddOn?: () => Promise<ServerAddOnCleanup>;
+  serverAddOn?: (
+    connection: ServerAddOnModuleToDesktopConnection,
+  ) => Promise<ServerAddOnCleanup>;
 }
 
 const loadPlugin = (_pluginName: string): ServerAddOnModule => {
@@ -21,19 +24,14 @@ const loadPlugin = (_pluginName: string): ServerAddOnModule => {
   return {serverAddOn: async () => async () => {}};
 };
 
-interface ServerAddOnConnection {
-  sendExpectResponse(payload: ExecuteMessage): Promise<ClientResponseType>;
-}
-
 // TODO: Fix potential race conditions when starting/stopping concurrently
 export class ServerAddOn {
   private owners: Set<string>;
-  // TODO: Implement connection
-  public readonly connection!: ServerAddOnConnection;
 
   constructor(
     public readonly pluginName: string,
     private readonly cleanup: ServerAddOnCleanup,
+    public readonly connection: ServerAddOnDesktopToModuleConnection,
     initialOwner: string,
   ) {
     this.owners = new Set(initialOwner);
@@ -53,7 +51,10 @@ export class ServerAddOn {
       `ServerAddOn ${pluginName} must export "serverAddOn" function.`,
     );
 
-    const cleanup = await serverAddOn();
+    const serverAddOnModuleToDesktopConnection =
+      new ServerAddOnModuleToDesktopConnection();
+
+    const cleanup = await serverAddOn(serverAddOnModuleToDesktopConnection);
     assert(
       typeof cleanup === 'function',
       `ServerAddOn ${pluginName} must return a clean up function, instead it returned ${typeof cleanup}.`,
@@ -64,7 +65,14 @@ export class ServerAddOn {
       await cleanup();
     };
 
-    return new ServerAddOn(pluginName, onStopCombined, initialOwner);
+    return new ServerAddOn(
+      pluginName,
+      onStopCombined,
+      new ServerAddOnDesktopToModuleConnection(
+        serverAddOnModuleToDesktopConnection,
+      ),
+      initialOwner,
+    );
   }
 
   addOwner(owner: string) {

desktop/flipper-server-core/src/plugins/ServerAddOnDesktopToModuleConnection.tsx

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import assert from 'assert';
+import {ClientResponseType, ExecuteMessage} from 'flipper-common';
+import {ServerAddOnModuleToDesktopConnection} from './ServerAddOnModuleToDesktopConnection';
+
+export class ServerAddOnDesktopToModuleConnection {
+  constructor(
+    private readonly moduleToDesktopConnection: ServerAddOnModuleToDesktopConnection,
+  ) {}
+
+  async sendExpectResponse({
+    method,
+    params,
+  }: ExecuteMessage): Promise<ClientResponseType> {
+    assert(
+      method === 'execute',
+      'ServerAddOnDesktopToModuleConnection supports only "execute" messages',
+    );
+    const response = await this.moduleToDesktopConnection.call(
+      params.method,
+      params.params,
+    );
+    const length = JSON.stringify(response).length;
+    return {
+      ...response,
+      length,
+    };
+  }
+}

desktop/flipper-server-core/src/plugins/ServerAddOnModuleToDesktopConnection.tsx

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import {ResponseMessage, ClientErrorType} from 'flipper-common';
+import {safeJSONStringify} from '../utils/safeJSONStringify';
+
+// TODO: Share with js-flipper? Is it worth it?
+type FlipperPluginReceiverRes =
+  | object
+  | string
+  | number
+  | boolean
+  | null
+  | undefined
+  | void;
+
+type FlipperPluginReceiver = (
+  data: any,
+) => FlipperPluginReceiverRes | Promise<FlipperPluginReceiverRes>;
+
+export class ServerAddOnModuleToDesktopConnection {
+  private subscriptions: Map<string, FlipperPluginReceiver> = new Map();
+
+  send() {
+    // TODO: Implement me
+  }
+
+  receive(method: string, receiver: FlipperPluginReceiver) {
+    this.subscriptions.set(method, receiver);
+  }
+
+  async call(method: string, params: unknown): Promise<ResponseMessage> {
+    try {
+      const receiver = this.subscriptions.get(method);
+      if (!receiver) {
+        throw new Error(`Receiver ${method} not found.`);
+      }
+      const response = await receiver.call(receiver, params);
+      return {
+        id: 0, // Not used in server <-> desktop connections. Used only in server <-> client connections.
+        success: response == null ? null : response,
+      };
+    } catch (e) {
+      const errorMessage: ClientErrorType =
+        e instanceof Error
+          ? {name: e.name, message: e.message, stacktrace: e.stack ?? ''}
+          : {name: 'Unknown', message: safeJSONStringify(e), stacktrace: ''};
+      return {
+        id: 0, // Not used in server <-> desktop connections. Used only in server <-> client connections.
+        error: errorMessage,
+      };
+    }
+  }
+}

desktop/flipper-server-core/src/utils/safeJSONStringify.tsx

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+export const safeJSONStringify = (data: unknown): string => {
+  try {
+    return JSON.stringify(data);
+  } catch {
+    return 'Unable to serialize';
+  }
+};