From 95a46abd393a4aa5735f7a6b45a45153a02e16e0 Mon Sep 17 00:00:00 2001 From: Stephan Ewen Date: Fri, 1 Dec 2023 06:55:06 +0100 Subject: [PATCH] Placeholder for the first pattern --- patterns/typescript/package.json | 23 ++++ .../src/deterministic_idempotency_tokens.ts | 102 ++++++++++++++++ patterns/typescript/tsconfig.json | 110 ++++++++++++++++++ 3 files changed, 235 insertions(+) create mode 100644 patterns/typescript/package.json create mode 100644 patterns/typescript/src/deterministic_idempotency_tokens.ts create mode 100644 patterns/typescript/tsconfig.json diff --git a/patterns/typescript/package.json b/patterns/typescript/package.json new file mode 100644 index 00000000..cb5eefff --- /dev/null +++ b/patterns/typescript/package.json @@ -0,0 +1,23 @@ +{ + "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": "ts-node-dev --watch ./src --respawn --transpile-only ./src/app.ts" + }, + "dependencies": { + "@restatedev/restate-sdk": "^0.5.1" + }, + "devDependencies": { + "ts-node-dev": "^1.1.1", + "typescript": "^5.0.2", + "esbuild": "^0.18.12" + } +} diff --git a/patterns/typescript/src/deterministic_idempotency_tokens.ts b/patterns/typescript/src/deterministic_idempotency_tokens.ts new file mode 100644 index 00000000..7169b4ca --- /dev/null +++ b/patterns/typescript/src/deterministic_idempotency_tokens.ts @@ -0,0 +1,102 @@ +import * as restate from "@restatedev/restate-sdk"; +import { randomUUID } from "crypto"; + +// ----------------- ----------------- +// Idempotency Tokens / Unique Tokens +// ----------------- ----------------- +// +// Idempotency tokens are useful when trying to make external calls idempotent, +// so that retries do not result in applying a change multiple times. +// +// One of the most famous examples for that is the Stripe idempotency token, +// which one attaches to a payment API call to ensure the payment is made +// just once. +// +// Generating idempotency tokens reliably can be surprisingly tricky, especially +// when they should be stable under various forms of failures or network partition +// scenarios. +// +// Restate makes this dead simple, in various different ways: +// + +// ---------------------------------------------------------------------------- +// ** option 1** use request parameter +// ---------------------------------------------------------------------------- + +// Restate persists the request parameter and ensures that all retries of the +// 'makeIdempotentCall1()' function get that persisted parameter. +// If a suitable token is in the request parameter, it is safe to use it + +async function makeIdempotentCall1(ctx: restate.RpcContext, request: any) { + + await ctx.sideEffect(() => api.makeCall(request, request.idempotencyToken)); +} + +// ---------------------------------------------------------------------------- +// ** option 2** stable deterministic random +// ---------------------------------------------------------------------------- + +// Restate offers deterministic Random number generators that are seeded with +// the durable invocation ID. This random number generator is guaranteed to +// always return the same value across all retries of the invocation, +// regardless of crashes/failover of either the service or the Restate runtime. + +async function makeIdempotentCall2(ctx: restate.RpcContext, request: any) { + + const idempotencyToken = ctx.rand.uuidv4(); + await ctx.sideEffect(() => api.makeCall(request, idempotencyToken)); +} + +// ---------------------------------------------------------------------------- +// ** option 3** Side effect UUID +// ---------------------------------------------------------------------------- + +// Side effects are guaranteed to agree on one specific return value before that +// value is passed to the application. The returned value will never change across +// retries of the invocation, regardless of crashes/failover of either the service +// or the Restate runtime. +// Note that this is more expensive than the 'ctx.rand.uuidv4()' variant, because +// it requires an additional consensus operation by the Restate runtime. + +async function makeIdempotentCall3(ctx: restate.RpcContext, request: any) { + + const idempotencyToken = await ctx.sideEffect(async () => randomUUID()) + await ctx.sideEffect(() => api.makeCall(request, idempotencyToken)); +} + +// ---------------------------------------------------------------------------- +// ** option 4** Reserve token in external system +// ---------------------------------------------------------------------------- + +// In some cases, it might be required to make an actual call to another API +// to reserve a token first. This can also be achieved with a sideEffect. +// +// While there may be cases where multiple calls to the tokens reservation API +// happen (in case of failures in the small window between the call and the time +// when the sideEffect commits), one value will ultimately be committed by Restate +// as the sideEffect's result and that same value will be seen by all executions +// and retries of that function invocation. + +async function makeIdempotentCall4(ctx: restate.RpcContext, request: any) { + + const idempotencyToken = await ctx.sideEffect(async () => { + // make call to external system to reserve a token + const response = await fetch('https://theSystemToReserveTheTokenIn:1234/api/tokens'); + if (!response.ok) { + // this will lead to automatic retries + throw new Error(`HTTP error! status: ${response.status}`); + } + return await response.text(); + }); + + await ctx.sideEffect(() => api.makeCall(request, idempotencyToken)); +} + + +// ---------------------------------------------------------------------------- +// MOCKS FOR THE PATTERNS +// ---------------------------------------------------------------------------- + +const api = { + makeCall: async (_request: any, _idempotencyToken: String) => Promise.resolve() +} \ No newline at end of file diff --git a/patterns/typescript/tsconfig.json b/patterns/typescript/tsconfig.json new file mode 100644 index 00000000..c3473680 --- /dev/null +++ b/patterns/typescript/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": "commonjs", /* 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 ''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/"] +}