feat: stub out ipc handlers

Author: KatoakDR

electron/main/ipc.ts

@@ -1,20 +1,62 @@
 import { ipcMain } from 'electron';
+import type { AppAPI } from '../preload';
 import { createLogger } from './logger';
 
 const logger = createLogger('ipc');
 
-export const registerIpcHandlers = (): void => {
-  // TODO rather than register unique ipcMain.handle('word') handlers,
-  //      use a design pattern where we have one ipcMain handler that
-  //      receives a standard payload.
-  //      In here, we then route the payload to the appropriate handler.
-  //      I saw this pattern on the webs somewhere.
-  registerPingHandler();
+interface IpcInvokeHandler<K extends keyof AppAPI> {
+  (params: Parameters<AppAPI[K]>): ReturnType<AppAPI[K]>;
+}
+
+type IpcHandlerRegistry = {
+  [channel in keyof AppAPI]: IpcInvokeHandler<channel>;
+};
+
+const pingIpcInvokeHandler: IpcInvokeHandler<
+  'ping'
+> = async (): Promise<string> => {
+  return 'pong';
 };
 
-const registerPingHandler = (): void => {
-  ipcMain.handle('ping', async (): Promise<string> => {
-    logger.info('ping');
-    return 'pong';
+const speakIpcInvokeHandler: IpcInvokeHandler<'speak'> = async (
+  params
+): Promise<void> => {
+  const [text] = params;
+  `Hello, ${text}`;
+};
+
+const climbIpcInvokeHandler: IpcInvokeHandler<'climb'> = async (
+  params
+): Promise<number> => {
+  const [data] = params;
+  return data.height * 2;
+};
+
+const ipcHandlerRegistry: IpcHandlerRegistry = {
+  ping: pingIpcInvokeHandler,
+  speak: speakIpcInvokeHandler,
+  climb: climbIpcInvokeHandler,
+};
+
+export const registerIpcHandlers = (): void => {
+  Object.keys(ipcHandlerRegistry).forEach((channel) => {
+    const handler = ipcHandlerRegistry[channel as keyof AppAPI];
+
+    if (!handler) {
+      logger.error('no handler registered for channel', { channel });
+      throw new Error(`[IPC:CHANNEL:INVALID] ${channel}`);
+    }
+
+    ipcMain.handle(channel, async (_event, ...params) => {
+      try {
+        logger.debug('handling channel request', { channel, params });
+        const result = await handler(params as any);
+        logger.debug('handled channel request', { channel, result });
+        return result;
+      } catch (error) {
+        logger.error('error handling channel request', { channel, error });
+        throw new Error(`[IPC:CHANNEL:ERROR] ${channel}: ${error?.message}`);
+      }
+    });
   });
 };

electron/preload/index.d.ts

@@ -3,9 +3,14 @@
  */
 declare const appAPI: {
   ping: () => Promise<string>;
+  speak: (text: string) => Promise<void>;
+  climb: (data: { height: number }) => Promise<number>;
 };
 declare global {
-  type AppAPI = typeof appAPI;
+  type TypeOfAppAPI = typeof appAPI;
+  type AppAPI = {
+    [K in keyof TypeOfAppAPI]: TypeOfAppAPI[K];
+  };
   interface Window {
     api: AppAPI;
   }

electron/preload/index.ts

@@ -4,16 +4,26 @@ import { contextBridge, ipcRenderer } from 'electron';
  * The index.d.ts file is auto-generated by the build process.
  */
 
-// Custom APIs for renderer
+// Custom APIs for renderer.
+// Proxies request to the main process then returns any response.
 const appAPI = {
   ping: async (): Promise<string> => {
-    // Proxies request to the main process then returns any response
     return ipcRenderer.invoke('ping');
   },
+  speak: async (text: string): Promise<void> => {
+    return ipcRenderer.invoke('speak', text);
+  },
+  climb: async (data: { height: number }): Promise<number> => {
+    return ipcRenderer.invoke('climb', data);
+  },
 };
 
 declare global {
-  type AppAPI = typeof appAPI;
+  type TypeOfAppAPI = typeof appAPI;
+
+  type AppAPI = {
+    [K in keyof TypeOfAppAPI]: TypeOfAppAPI[K];
+  };
 
   interface Window {
     api: AppAPI;

electron/renderer/pages/home.tsx

@@ -8,8 +8,11 @@ const HomePage: React.FC = (): ReactNode => {
   const { logger } = useLogger('page:grid');
   useEffect(() => {
     runInBackground(async () => {
-      const response = await window.api.ping();
-      logger.info(response); // pong
+      logger.info('>> ping', { response: await window.api.ping() });
+      logger.info('>> speak', { response: await window.api.speak('electron') });
+      logger.info('>> climb', {
+        response: await window.api.climb({ height: 2 }),
+      });
     });
   }, []);
   // --