Added workflow example

basics/basics-typescript/src/3_workflows.ts

@@ -10,6 +10,97 @@
  */
 
 import * as restate from "@restatedev/restate-sdk";
-import { maybeCrash } from "./utils/failures";
+import { workflow as wf } from "@restatedev/restate-sdk";
+import { createUserEntry, sendEmailWithLink } from "./utils/workflow_stubs";
+import { WorkflowStartResult } from "@restatedev/restate-sdk/dist/workflows/workflow";
 
-// ToDo
+//
+// A simple workflow for a user signup and email verification.
+//
+//  - the main workflow is in the run() method
+//  - any number of other methods can be added to implement interactions
+//    with the workflow.
+//
+const myWorkflow = wf.workflow("usersignup", {
+
+    // --- The workflow logic is in the run() function ---
+
+    run: async (ctx: wf.WfContext, params: { name: string, email: string} ) => {
+        const { name, email } = params;
+        const userId = ctx.workflowId();
+
+        // publish state, for the world to see our progress
+        ctx.set("stage", "Creating User");
+
+        // use all the standard durable execution features here
+        await ctx.sideEffect(() => createUserEntry({ userId, name }));
+
+        ctx.set("stage", "Email Verification");
+
+        // send the email with the verification secret
+        const secret = await ctx.sideEffect(async () => crypto.randomUUID());        
+        ctx.sideEffect(() => sendEmailWithLink({ email, secret }));
+
+        try {
+            // the promise here is resolved or rejected by the additional workflow methods below
+            const clickSecret = await ctx.promise<string>("email-link");
+            if (clickSecret !== secret) {
+                throw new restate.TerminalError("Wrong secret from email link");
+            }
+        } catch (err: any) {
+            ctx.set("stage", "Verification failed: " + err.message);
+            return;
+        }
+
+        ctx.set("stage", "User verified");
+    },
+
+    // --- various interactions for queries and signals ---
+
+    getStage: (ctx: wf.SharedWfContext) => {
+        // read the state to get the stage where the workflow is
+        return ctx.get("stage");
+    },
+
+    verifyEmail: async (ctx: wf.SharedWfContext, request: { secret: string }) => {
+        // resolve the durable promise to let the awaiter know
+        ctx.promise<string>("email-link").resolve(request.secret);
+    },
+
+    abortVerification: async (ctx: wf.SharedWfContext) => {
+        // failing the durable promise will throw an Error for the awaiting thread
+        ctx.promise<string>("email-link").fail("User aborted verification");
+    },
+})
+
+export const workflowApi = myWorkflow.api;
+
+// ---------- ⬆️⬆️ deploy this as a container, lambda, etc. ⬆️⬆️ ----------
+
+
+// start it via an HTTP call.
+// `curl restate:8080/usersignup/submit --json '{ "request": {
+//                                                   "workflowId": "signup-userid1",
+//                                                   "name": "Bob",
+//                                                   "email": "[email protected]"
+//                                               } }'
+
+// or programatically
+async function signupUser(userId: string, name: string, email: string) {
+    const rs = restate.clients.connect("http://restate:8080");
+    const { client, status } = await rs.submitWorkflow(workflowApi, "signup-" + userId, { name, email });
+
+    if (status != WorkflowStartResult.STARTED) {
+        throw new Error("User ID already taken");
+    }
+
+    await client.result();
+}
+
+// interact with the workflow  from any other code
+async function verifyEmail(userId: string, emailSecret: string) {
+    const rs = restate.clients.connect("http://restate:8080");
+    const { client, status } = await rs.connectToWorkflow(workflowApi, "signup-" + userId);
+
+    client.workflowInterface().verifyEmail({ secret: emailSecret });
+}

basics/basics-typescript/src/utils/workflow_stubs.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2024 - Restate Software, Inc., Restate GmbH
+ *
+ * This file is part of the Restate Examples for the Node.js/TypeScript SDK,
+ * which is released under the MIT license.
+ *
+ * You can find a copy of the license in the file LICENSE
+ * in the root directory of this repository or package or at
+ * https://github.com/restatedev/examples/blob/main/LICENSE
+ */
+
+export async function createUserEntry(entry: { userId: string, name: string }) {
+}
+
+export async function sendEmailWithLink(details: { email: string, secret: string}) {
+}