Clean up utility examples in the SDK

Author: StephanEwen

examples/example.ts

@@ -9,8 +9,6 @@
  * https://github.com/restatedev/sdk-typescript/blob/main/LICENSE
  */
 
-/* eslint-disable no-console */
-
 /*
  * A simple example program using the Restate dynamic RPC-based API.
  *
@@ -20,43 +18,45 @@
 
 import * as restate from "../src/public_api";
 
-// handler implementations
-
-const doGreet = async (
-  ctx: restate.RpcContext,
-  name: string
-): Promise<string> => {
-  const countSoFar = await ctx.rpc<apiType>({ path: "counter" }).count(name);
-
-  const message = `Hello ${name}! at the ${countSoFar + 1}th time`;
-
-  ctx.send(greeterApi).logger(message);
-  ctx.sendDelayed(greeterApi, 100).logger("delayed " + message);
+//
+// The main entry point for the service, receiving the greeting request and name.
+//
+const greeter = restate.router({
+  greet: async (ctx: restate.RpcContext, name: string) => {
+    // blocking RPC call to a keyed service (here supplying type and path separately)
+    const countSoFar = await ctx
+      .rpc<counterApiType>({ path: "counter" })
+      .count(name);
 
-  return message;
-};
+    const message = `Hello ${name}, for the ${countSoFar + 1}th time!`;
 
-const countKeeper = async (ctx: restate.RpcContext): Promise<number> => {
-  const seen = (await ctx.get<number>("seen")) || 0;
-  ctx.set("seen", seen + 1);
-  return seen;
-};
+    // sending messages to ourselves, immediately and delayed
+    ctx.send(greeterApi).logger(message);
+    ctx.sendDelayed(greeterApi, 100).logger("delayed " + message);
 
-// routers (with some in-line handlers)
+    return message;
+  },
 
-const greeter = restate.router({
-  greet: doGreet,
   logger: async (ctx: restate.RpcContext, msg: string) => {
     ctx.console.log(" HEEEELLLLOOOOO! " + msg);
   },
 });
 
+//
+// The stateful aux service that keeps the counts.
+// This could in principle be the same service as the greet service, we just separate
+// them here to have this multi-service setup for testing.
+//
 const counter = restate.keyedRouter({
-  count: countKeeper,
+  count: async (ctx: restate.RpcContext): Promise<number> => {
+    const seen = (await ctx.get<number>("seen")) ?? 0;
+    ctx.set("seen", seen + 1);
+    return seen;
+  },
 });
 
-type apiType = typeof counter;
 const greeterApi: restate.ServiceApi<typeof greeter> = { path: "greeter" };
+type counterApiType = typeof counter;
 
 // restate server
 

examples/grpc_example.ts

@@ -33,10 +33,9 @@ export class GreeterService implements TestGreeter {
     const ctx = restate.useContext(this);
 
     // state
-    let seen = (await ctx.get<number>("seen")) || 0;
+    let seen = (await ctx.get<number>("seen")) ?? 0;
     seen += 1;
-
-    await ctx.set("seen", seen);
+    ctx.set("seen", seen);
 
     // return the final response
     return TestResponse.create({

examples/handler_example.ts

@@ -9,48 +9,44 @@
  * https://github.com/restatedev/sdk-typescript/blob/main/LICENSE
  */
 
-/* eslint-disable no-console */
-
 /*
- * A simple example program using the Restate's event handlers.
+ * A simple example program showing how to let services listen to events produced
+ * by systems like Kafka.
  */
 
 import * as restate from "../src/public_api";
 
-const registration = async (ctx: restate.RpcContext, event: restate.Event) => {
-  // store in state the user's information as coming from the registeration event
-  const { name } = event.json<{ name: string }>();
-  ctx.set("name", name);
-};
-
-const email = async (ctx: restate.RpcContext, event: restate.Event) => {
-  // store in state the user's information as coming from the email event
-  const { email } = event.json<{ email: string }>();
-  ctx.set("email", email);
-};
-
 type UserProfile = {
   id: string;
   name: string;
   email: string;
 };
 
-const get = async (
-  ctx: restate.RpcContext,
-  id: string
-): Promise<UserProfile> => {
-  return {
-    id,
-    name: (await ctx.get<string>("name")) ?? "",
-    email: (await ctx.get<string>("email")) ?? "",
-  };
-};
-
-const profile = restate.keyedRouter({
-  registration: restate.keyedEventHandler(registration),
-  email: restate.keyedEventHandler(email),
-  get,
+const profileService = restate.keyedRouter({
+  registration: restate.keyedEventHandler(
+    async (ctx: restate.RpcContext, event: restate.Event) => {
+      // store in state the user's information as coming from the registeration event
+      const { name } = event.json<{ name: string }>();
+      ctx.set("name", name);
+    }
+  ),
+
+  email: restate.keyedEventHandler(
+    async (ctx: restate.RpcContext, event: restate.Event) => {
+      // store in state the user's information as coming from the email event
+      const { email } = event.json<{ email: string }>();
+      ctx.set("email", email);
+    }
+  ),
+
+  get: async (ctx: restate.RpcContext, id: string): Promise<UserProfile> => {
+    return {
+      id,
+      name: (await ctx.get<string>("name")) ?? "",
+      email: (await ctx.get<string>("email")) ?? "",
+    };
+  },
 });
 
 // restate server
-restate.createServer().bindKeyedRouter("profile", profile).listen(9080);
+restate.createServer().bindKeyedRouter("profile", profileService).listen(9080);