durable rpc and task queue example

typescript/basics/src/3_workflows.ts

@@ -18,7 +18,7 @@ import { createUserEntry, sendEmailWithLink } from "./utils/stubs";
 //  - Additional methods interact with the workflow.
 // Each workflow instance has a unique ID and runs only once (to success or failure).
 //
-const myWorkflow = restate.workflow({
+const singupWorkflow = restate.workflow({
   name: "usersignup",
   handlers: {
     // --- The workflow logic ---
@@ -50,9 +50,9 @@ const myWorkflow = restate.workflow({
   },
 });
 
-export type SignupApi = typeof myWorkflow;
+export type SignupApi = typeof singupWorkflow;
 
-restate.endpoint().bind(myWorkflow).listen();
+restate.endpoint().bind(singupWorkflow).listen(9080);
 // or .handler() to run on Lambda, Deno, Bun, Cloudflare Workers, ...
 
 /*

typescript/patterns-use-cases/async-task-queue/README.md

@@ -0,0 +1,5 @@
+# Hello world - TypeScript example
+
+Sample project configuration of a Restate service using the TypeScript SDK.
+
+Have a look at the [TypeScript Quickstart guide](https://docs.restate.dev/get_started/quickstart?sdk=ts) for more information on how to use this project.

typescript/patterns-use-cases/async-task-queue/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "restate-ts-template",
+  "version": "0.0.1",
+  "description": "Template for JavaScript/TypeScript services running with Restate (https://github.com/restatedev/) ",
+  "main": "app.js",
+  "type": "commonjs",
+  "scripts": {
+    "build": "tsc --noEmitOnError",
+    "prebundle": "rm -rf dist",
+    "bundle": "esbuild src/app.ts --bundle --minify --sourcemap --platform=node --target=es2020 --outfile=dist/index.js",
+    "postbundle": "cd dist && zip -r index.zip index.js*",
+    "app": "node ./dist/app.js",
+    "app-dev": "tsx watch ./src/app.ts"
+  },
+  "dependencies": {
+    "@restatedev/restate-sdk": "^1.4.0",
+    "@restatedev/restate-sdk-clients": "^1.4.0"
+  },
+  "devDependencies": {
+    "@types/node": "^20.14.2",
+    "esbuild": "^0.21.5",
+    "tsx": "^4.19.2",
+    "typescript": "^5.4.5"
+  }
+}

typescript/patterns-use-cases/async-task-queue/src/async_task_service.ts

@@ -0,0 +1,25 @@
+// --------------- define async task logic as a service handler ---------------
+
+import * as restate from "@restatedev/restate-sdk";
+import { Context } from "@restatedev/restate-sdk";
+
+const asyncTaskService = restate.service({
+  name: "taskWorker",
+  handlers: {
+    runTask: async (ctx: Context, params: TaskOpts) => {
+      return someHeavyWork(params);
+    },
+  },
+});
+
+export type AsyncTaskService = typeof asyncTaskService;
+
+restate.endpoint().bind(asyncTaskService).listen(9080);
+
+
+// ----------------------- Stubs to please the compiler -----------------------
+export type TaskOpts = {id: string, task: string};
+
+function someHeavyWork(work: TaskOpts) {
+  return "Work!";
+}

typescript/patterns-use-cases/async-task-queue/src/task_submitter.ts

@@ -0,0 +1,39 @@
+import * as restate from "@restatedev/restate-sdk-clients";
+import { AsyncTaskService, TaskOpts } from "./async_task_service";
+import {SendOpts} from "@restatedev/restate-sdk-clients";
+
+/*
+ * Restate is as a sophisticated task queue, with extra features like:
+ * - delaying execution and reliable timers
+ * - stateful tasks
+ * - queues per key (>< per partition; slow tasks for a key don't block others)
+ * - retries and recovery upon failures
+ *
+ * Every handler in Restate is executed asynchronously and can be treated
+ * as a reliable asynchronous task.
+ */
+
+const RESTATE_URL = "http://localhost:8080";
+
+async function submitAndAwaitTask(task: TaskOpts) {
+  const restateClient = restate.connect({ url: RESTATE_URL });
+
+  // submit the task; similar to publishing a message to a queue
+  // Restate ensures the task is executed exactly once
+  const taskHandle = await restateClient
+    .serviceSendClient<AsyncTaskService>({ name: "taskWorker" })
+    .runTask(
+      task,
+      // use a stable uuid as an idempotency key
+      // optionally, execute the task later via SendOpts.from({ delay: 1000 })
+      SendOpts.from({ idempotencyKey: task.id })
+    );
+
+  // await the task's result
+  const result = await restateClient.result(taskHandle);
+}
+
+async function attachToTaskFromOtherProcess(taskHandle: string) {
+  const restateClient = restate.connect({ url: RESTATE_URL });
+  const result = await restateClient.result<string>(JSON.parse(taskHandle));
+}

typescript/patterns-use-cases/async-task-queue/tsconfig.json

@@ -0,0 +1,110 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig to read more about this file */
+
+    /* Projects */
+    // "incremental": true,                              /* Save .tsbuildinfo files to allow for incremental compilation of projects. */
+    // "composite": true,                                /* Enable constraints that allow a TypeScript project to be used with project references. */
+    // "tsBuildInfoFile": "./.tsbuildinfo",              /* Specify the path to .tsbuildinfo incremental compilation file. */
+    // "disableSourceOfProjectReferenceRedirect": true,  /* Disable preferring source files instead of declaration files when referencing composite projects. */
+    // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */
+    // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
+
+    /* Language and Environment */
+    "target": "esnext",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+    "lib": ["esnext"],                                   /* Specify a set of bundled library declaration files that describe the target runtime environment. */
+    // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
+    // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
+    // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */
+    // "jsxFragmentFactory": "",                         /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
+    // "jsxImportSource": "",                            /* Specify module specifier used to import the JSX factory functions when using 'jsx: react-jsx*'. */
+    // "reactNamespace": "",                             /* Specify the object invoked for 'createElement'. This only applies when targeting 'react' JSX emit. */
+    // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
+    // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
+    // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
+
+    /* Modules */
+    "module": "nodenext",                                /* Specify what module code is generated. */
+    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
+    // "moduleResolution": "node10",                     /* Specify how TypeScript looks up a file from a given module specifier. */
+    // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
+    // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
+    // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
+    // "typeRoots": [],                                  /* Specify multiple folders that act like './node_modules/@types'. */
+    // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
+    // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
+    // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
+    // "resolveJsonModule": true,                        /* Enable importing .json files. */
+    // "allowArbitraryExtensions": true,                 /* Enable importing files with any extension, provided a declaration file is present. */
+    // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
+
+    /* JavaScript Support */
+    "allowJs": true,                                     /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
+    // "checkJs": true,                                  /* Enable error reporting in type-checked JavaScript files. */
+    // "maxNodeModuleJsDepth": 1,                        /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */
+
+    /* Emit */
+    "declaration": true,                                 /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
+    "declarationMap": true,                              /* Create sourcemaps for d.ts files. */
+    "sourceMap": true,                                   /* Create source map files for emitted JavaScript files. */
+    "outDir": "./dist",                                  /* Specify an output folder for all emitted files. */
+    // "emitDeclarationOnly": true,                      /* Only output d.ts files and not JavaScript files. */
+    // "inlineSourceMap": true,                          /* Include sourcemap files inside the emitted JavaScript. */
+    // "outFile": "./",                                  /* Specify a file that bundles all outputs into one JavaScript file. If 'declaration' is true, also designates a file that bundles all .d.ts output. */
+    // "removeComments": true,                           /* Disable emitting comments. */
+    // "noEmit": true,                                   /* Disable emitting files from a compilation. */
+    // "importHelpers": true,                            /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
+    // "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types. */
+    // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
+    // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
+    // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSources": true,                            /* Include source code in the sourcemaps inside the emitted JavaScript. */
+    // "emitBOM": true,                                  /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
+    // "newLine": "crlf",                                /* Set the newline character for emitting files. */
+    // "stripInternal": true,                            /* Disable emitting declarations that have '@internal' in their JSDoc comments. */
+    // "noEmitHelpers": true,                            /* Disable generating custom helper functions like '__extends' in compiled output. */
+    // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
+    // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
+    // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
+    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
+
+    /* Interop Constraints */
+    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
+    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
+    "allowSyntheticDefaultImports": true,                /* Allow 'import x from y' when a module doesn't have a default export. */
+    // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
+    // "verbatimModuleSyntax": true,                     /* Do not transform or elide any imports or exports not marked as type-only, ensuring they are written in the output file's format based on the 'module' setting. */
+    // "preserveSymlinks": true,                         /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
+
+    /* Type Checking */
+    "strict": true,                                      /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                            /* Enable error reporting for expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,                         /* When type checking, take into account 'null' and 'undefined'. */
+    // "strictFunctionTypes": true,                      /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
+    // "strictBindCallApply": true,                      /* Check that the arguments for 'bind', 'call', and 'apply' methods match the original function. */
+    // "strictPropertyInitialization": true,             /* Check for class properties that are declared but not set in the constructor. */
+    // "noImplicitThis": true,                           /* Enable error reporting when 'this' is given the type 'any'. */
+    // "useUnknownInCatchVariables": true,               /* Default catch clause variables as 'unknown' instead of 'any'. */
+    // "alwaysStrict": true,                             /* Ensure 'use strict' is always emitted. */
+    // "noUnusedLocals": true,                           /* Enable error reporting when local variables aren't read. */
+    // "noUnusedParameters": true,                       /* Raise an error when a function parameter isn't read. */
+    // "exactOptionalPropertyTypes": true,               /* Interpret optional property types as written, rather than adding 'undefined'. */
+    // "noImplicitReturns": true,                        /* Enable error reporting for codepaths that do not explicitly return in a function. */
+    // "noFallthroughCasesInSwitch": true,               /* Enable error reporting for fallthrough cases in switch statements. */
+    // "noUncheckedIndexedAccess": true,                 /* Add 'undefined' to a type when accessed using an index. */
+    // "noImplicitOverride": true,                       /* Ensure overriding members in derived classes are marked with an override modifier. */
+    // "noPropertyAccessFromIndexSignature": true,       /* Enforces using indexed accessors for keys declared using an indexed type. */
+    // "allowUnusedLabels": true,                        /* Disable error reporting for unused labels. */
+    // "allowUnreachableCode": true,                     /* Disable error reporting for unreachable code. */
+
+    /* Completeness */
+    "skipLibCheck": true,                                /* Skip type checking all .d.ts files. */
+    "skipDefaultLibCheck": true                          /* Skip type checking .d.ts files that are included with TypeScript. */
+  },
+  "include": ["src/"]
+}

typescript/patterns-use-cases/async-tasks-payment-signals/src/payment_handler.ts

@@ -35,22 +35,24 @@ type PaymentRequest = {
 };
 
 async function processPayment(ctx: restate.Context, request: PaymentRequest) {
+  const {paymentMethodId, amount, delayedStatus} = request;
+
   verifyPaymentRequest(request);
 
   // Generate a deterministic idempotency key
   const idempotencyKey = ctx.rand.uuidv4();
 
   // Initiate a listener for external calls for potential webhook callbacks
-  const webhookPromise = ctx.awakeable<Stripe.PaymentIntent>();
+  const { id: intentWebhookId, promise: intentPromise } = ctx.awakeable<Stripe.PaymentIntent>();
 
   // Make a synchronous call to the payment service
   const paymentIntent = await ctx.run("stripe call", () =>
     stripe_utils.createPaymentIntent({
-      paymentMethodId: request.paymentMethodId,
-      amount: request.amount,
+      paymentMethodId,
+      amount,
       idempotencyKey,
-      webhookPromiseId: webhookPromise.id,
-      delayedStatus: request.delayedStatus,
+      intentWebhookId,
+      delayedStatus,
     })
   );
 
@@ -70,7 +72,7 @@ async function processPayment(ctx: restate.Context, request: PaymentRequest) {
 
   // We will now wait for the webhook call to complete this promise.
   // Check out the handler below.
-  const processedPaymentIntent = await webhookPromise.promise;
+  const processedPaymentIntent = await intentPromise;
 
   console.log(`Webhook call for ${idempotencyKey} received!`);
   stripe_utils.ensureSuccess(processedPaymentIntent.status);

typescript/patterns-use-cases/async-tasks-payment-signals/src/utils/stripe_utils.ts

@@ -49,7 +49,7 @@ export async function createPaymentIntent(request: {
   paymentMethodId: string;
   amount: number;
   idempotencyKey: string;
-  webhookPromiseId: string;
+  intentWebhookId: string;
   delayedStatus?: boolean;
 }): Promise<Stripe.PaymentIntent> {
   const requestOptions = {
@@ -66,7 +66,7 @@ export async function createPaymentIntent(request: {
         confirmation_method: "automatic",
         return_url: "https://restate.dev/", // some random URL
         metadata: {
-          restate_callback_id: request.webhookPromiseId,
+          restate_callback_id: request.intentWebhookId,
         },
       },
       requestOptions

typescript/patterns-use-cases/microservices-durable-rpc/README.md

@@ -0,0 +1,22 @@
+# Microservices: Durable RPC
+
+This example shows an example of:
+- **Durable RPC** with exactly-once semantics
+- **Requests with idempotency keys**: Ensuring that the same request is processed only once
+
+
+
+## Running the Example
+
+Run Restate locally (`npx restate-server`).
+
+Run the Restate service: `cd restate-app && npm run app`
+
+Register the service: `npx restate deployments register http://localhost:5000`
+
+Run the Express service: `cd express-app && npm run app`
+
+Send a request to the Express service:
+```
+curl -X POST localhost:5000/reserve/12345/abcde
+```

typescript/patterns-use-cases/microservices-durable-rpc/express-app/app.ts

@@ -0,0 +1,29 @@
+import * as restate from "@restatedev/restate-sdk-clients";
+import { Opts } from "@restatedev/restate-sdk-clients";
+import express, { Request, Response } from "express";
+import { ProductService } from "product-service";
+
+const app = express();
+
+const RESTATE_URL = "http://localhost:8080";
+const restateClient = restate.connect({ url: RESTATE_URL });
+
+app.post("/reserve/:productId/:reservationId", async (req: Request, res: Response) => {
+    const { productId, reservationId } = req.params;
+
+    // Durable RPC call to the product service
+    // Restate registers the request and makes sure runs to completion exactly once
+    const products = restateClient
+        .objectClient<ProductService>({ name: "product" }, productId);
+    const reservation = await products.reserve(
+        // Restate deduplicates requests with the same idempotency key
+        Opts.from({ idempotencyKey: reservationId })
+    );
+
+    console.log("Reservation result", reservation);
+    return res.json(reservation);
+});
+
+app.listen(5000, () => {
+    console.log("Server is running on port 5000");
+})