AWS Durable Execution Testing SDK for JavaScript

Testing utilities for the AWS Durable Execution SDK for JavaScript and TypeScript.

Features

This package provides testing tools for durable functions both locally and in the cloud:

• LocalDurableTestRunner - Execute and test durable functions locally without AWS deployment

  • Time-skipping support - Skip wait operations and delays for faster test execution
  • Function registration - Register additional functions for chained invoke testing
  • Full operation inspection - Access detailed information about steps, waits, callbacks, and more
  • Mock-friendly - Works seamlessly with Jest and other mocking frameworks

• CloudDurableTestRunner - Test against deployed AWS Lambda functions

  • Real environment testing - Validate behavior against actual your actual deployed AWS Lambda function
  • Configurable invocation - Support for different invocation types and polling intervals

• Testing Capabilities

  • Operation assertions - Inspect individual operations by name, index, or ID
  • Status and result validation - Verify execution status, results, and error conditions
  • Callback testing - Send callback responses and verify callback behavior
  • Retry validation - Test step retry logic and failure scenarios

Installation

npm install --save-dev @aws/durable-execution-sdk-js-testing

Quick Start

Handler Code

import {
  withDurableExecution,
  DurableContext,
} from "@aws/durable-execution-sdk-js";

const handler = async (event: any, context: DurableContext) => {
  // Execute a durable step with automatic retry
  const userData = await context.step("fetch-user", async () =>
    fetchUserFromDB(event.userId),
  );

  // Wait for 5 seconds
  await context.wait({ seconds: 5 });

  // Process data in another step
  const result = await context.step("process-user", async () =>
    processUser(userData),
  );

  return result;
};

export const lambdaHandler = withDurableExecution(handler);

Test Code

Local Testing

import {
  LocalDurableTestRunner,
  WaitingOperationStatus,
} from "@aws/durable-execution-sdk-js-testing";
import { lambdaHandler } from "./lambdaHandler";

beforeAll(() =>
  LocalDurableTestRunner.setupTestEnvironment({
    skipTime: true,
  }),
);

afterAll(() => LocalDurableTestRunner.teardownTestEnvironment());

describe("LocalDurableTestRunner", () => {
  let runner;

  beforeEach(() => {
    runner = new LocalDurableTestRunner({
      handlerFunction: lambdaHandler,
    });
  });

  it("should wait for 5 seconds and return result", async () => {
    const execution = await runner.run({ payload: { userId: "123" } });

    expect(execution.getStatus()).toBe("SUCCEEDED");
    expect(execution.getOperations()).toHaveLength(3); // fetch-user, wait, process-user

    // Check the fetch-user step
    const fetchStep = runner.getOperation("fetch-user");
    await fetchStep.waitForData(WaitingOperationStatus.COMPLETED);
    const fetchDetails = fetchStep.getStepDetails();
    expect(fetchDetails?.result).toBeDefined();

    // Check the wait operation
    const waitOp = runner.getOperationByIndex(1);
    const waitDetails = waitOp.getWaitDetails();
    expect(waitDetails?.waitSeconds).toBe(5);

    // Check the process-user step
    const processStep = runner.getOperation("process-user");
    await processStep.waitForData(WaitingOperationStatus.COMPLETED);
    const processDetails = processStep.getStepDetails();
    expect(processDetails?.result).toBeDefined();
  });
});

Cloud Testing

import {
  CloudDurableTestRunner,
  WaitingOperationStatus,
} from "@aws/durable-execution-sdk-js-testing";

describe("CloudDurableTestRunner", () => {
  let runner;

  beforeEach(() => {
    runner = new CloudDurableTestRunner({
      functionName: "my-durable-function", // Your deployed function name
    });
  });

  it("should wait for 5 seconds and return result", async () => {
    const execution = await runner.run({ payload: { userId: "123" } });

    expect(execution.getStatus()).toBe("SUCCEEDED");
    expect(execution.getOperations()).toHaveLength(3); // fetch-user, wait, process-user

    // Check the fetch-user step
    const fetchStep = runner.getOperation("fetch-user");
    const fetchDetails = fetchStep.getStepDetails();
    expect(fetchDetails?.result).toBeDefined();
    expect(fetchDetails?.attempt).toBe(1);

    // Check the wait operation
    const waitOp = runner.getOperationByIndex(1);
    const waitDetails = waitOp.getWaitDetails();
    expect(waitDetails?.waitSeconds).toBe(5);

    // Check the process-user step
    const processStep = runner.getOperation("process-user");
    const processDetails = processStep.getStepDetails();
    expect(processDetails?.result).toBeDefined();
  });
});

LocalDurableTestRunner

Run durable functions locally with a simulated durable execution backend.

import { LocalDurableTestRunner } from "@aws/durable-execution-sdk-js-testing";
import { handler } from "./my-durable-function";

// Set up test environment with optional time skipping
await LocalDurableTestRunner.setupTestEnvironment({
  skipTime: true, // Skip wait delays for faster tests
});

const runner = new LocalDurableTestRunner({
  handlerFunction: handler,
});

const execution = await runner.run({ payload: { test: "data" } });

// Assert on results
expect(execution.getStatus()).toBe("SUCCEEDED");
expect(execution.getResult()).toEqual(expectedValue);

// Assert on operations
const operations = execution.getOperations();
expect(operations).toHaveLength(3);

// Clean up test environment
await LocalDurableTestRunner.teardownTestEnvironment();

Mocking

Mock external dependencies using Jest or your preferred testing framework:

import { LocalDurableTestRunner } from "@aws/durable-execution-sdk-js-testing";

// Mock external functions
jest.mock("../services/userService", () => ({
  fetchUserFromDB: jest.fn(),
  processUser: jest.fn(),
}));

import { fetchUserFromDB, processUser } from "../services/userService";
import { lambdaHandler } from "./lambdaHandler";

const mockFetchUser = fetchUserFromDB as jest.MockedFunction<
  typeof fetchUserFromDB
>;
const mockProcessUser = processUser as jest.MockedFunction<typeof processUser>;

describe("Mocked Dependencies", () => {
  let runner: LocalDurableTestRunner;

  beforeAll(() =>
    LocalDurableTestRunner.setupTestEnvironment({ skipTime: true }),
  );
  afterAll(() => LocalDurableTestRunner.teardownTestEnvironment());

  beforeEach(() => {
    runner = new LocalDurableTestRunner({ handlerFunction: lambdaHandler });

    // Reset mocks
    mockFetchUser.mockClear();
    mockProcessUser.mockClear();
  });

  it("should call mocked functions and return expected results", async () => {
    // Setup mocks
    const userData = { id: "123", name: "John Doe" };
    const processedResult = { id: "123", processed: true };

    mockFetchUser.mockResolvedValue(userData);
    mockProcessUser.mockResolvedValue(processedResult);

    // Run test
    const execution = await runner.run({ payload: { userId: "123" } });

    // Verify results
    expect(execution.getStatus()).toBe("SUCCEEDED");
    expect(execution.getResult()).toEqual(processedResult);

    // Verify mock calls
    expect(mockFetchUser).toHaveBeenCalledWith("123");
    expect(mockProcessUser).toHaveBeenCalledWith(userData);

    // Verify operations
    const fetchStep = runner.getOperation("fetch-user");
    const fetchDetails = fetchStep.getStepDetails();
    expect(fetchDetails?.result).toEqual(userData);
  });
});

Function Registration

Register additional functions that can be invoked during local testing of chained invocations:

Handler Code

const mainHandler = withDurableExecution(async (event, context) => {
  await context.invoke("workflow-a:$LATEST");
  await context.invoke("workflow-b:$LATEST");

  await context.invoke("utility-function");
  await context.invoke("utility-helper");
});

Test code

const runner = new LocalDurableTestRunner({ handlerFunction: mainHandler });

// Register durable functions
runner.registerDurableFunction("workflow-a:$LATEST", durableWorkflowA);

// Register regular functions
runner.registerFunction("utility-function", utilityHandler);

// Method chaining is supported
runner
  .registerDurableFunction("workflow-b:$LATEST", durableWorkflowB)
  .registerFunction("helper", helperHandler);

CloudDurableTestRunner

Test against deployed Lambda functions in AWS.

import {
  CloudDurableTestRunner,
  InvocationType,
} from "@aws/durable-execution-sdk-js-testing";
import { LambdaClient } from "@aws-sdk/client-lambda";

const runner = new CloudDurableTestRunner({
  functionName: "MyDurableFunction",
  client: new LambdaClient({ region: "us-east-1" }), // optional
  config: {
    pollInterval: 1000, // optional, default 1000ms
    invocationType: InvocationType.RequestResponse, // optional
  },
});

const execution = await runner.run({ payload: { userId: "123" } });

expect(execution.getStatus()).toBe("SUCCEEDED");

Test Result API

Both runners return a TestResult object with methods for assertions:

const execution = await runner.run();

// Get execution status and results
execution.getStatus(); // "SUCCEEDED" | "FAILED" | "RUNNING" | etc.
execution.getResult(); // Returns the function result
execution.getError(); // Returns error details if failed

// Get operations
execution.getOperations(); // All operations
execution.getOperations({ status: "SUCCEEDED" }); // Filter by status

// Get execution history and invocations
execution.getHistoryEvents(); // Detailed event history
execution.getInvocations(); // Handler invocation details

// Print operations table to console
execution.print(); // Default columns
execution.print({ name: true, status: true, duration: true }); // Custom columns

Operation Assertions

Access specific operations for detailed assertions:

// Get operations by different methods
const operation = runner.getOperation("my-step"); // By name
const firstOp = runner.getOperationByIndex(0); // By execution order
const secondNamedOp = runner.getOperationByNameAndIndex("my-step", 1); // By name + index
const opById = runner.getOperationById("abc123"); // By unique ID

// Wait for operation data to be available
await operation.waitForData(); // Default to STARTED status
await operation.waitForData(WaitingOperationStatus.COMPLETED);

// Get operation details based on type
const stepDetails = operation.getStepDetails(); // For step operations
const contextDetails = operation.getContextDetails(); // For context operations
const callbackDetails = operation.getCallbackDetails(); // For callback operations
const waitDetails = operation.getWaitDetails(); // For wait operations

// Get basic operation information
operation.getName();
operation.getStatus();
operation.getStartTimestamp();
operation.getEndTimestamp();

Callback Operations

For callback operations, you can send responses:

const callback = runner.getOperation("my-callback");
await callback.waitForData(WaitingOperationStatus.SUBMITTED);

// Send callback responses
await callback.sendCallbackSuccess("result data");
await callback.sendCallbackFailure({ errorMessage: "Failed" });
await callback.sendCallbackHeartbeat();

Configuration Options

LocalDurableTestRunner

// Constructor
new LocalDurableTestRunner({ handlerFunction: handler });

// Environment setup
await LocalDurableTestRunner.setupTestEnvironment({ skipTime: true });

// Environment teardown
await LocalDurableTestRunner.teardownTestEnvironment();

CloudDurableTestRunner

// Basic configuration
new CloudDurableTestRunner({ functionName: "MyFunction:$LATEST" });

// Advanced configuration
new CloudDurableTestRunner({
  functionName: "MyFunction:$LATEST",
  client: new LambdaClient({ region: "us-east-1" }),
  config: { pollInterval: 500, invocationType: InvocationType.Event },
});

Reset Runner State

The reset() method is required if you reuse the same runner instance between tests. Data about an individual execution is cleared from the runner instance when reset() is called.

describe("Reusing Runner Instance", () => {
  let runner: LocalDurableTestRunner;

  beforeAll(() => {
    // Create runner once
    runner = new LocalDurableTestRunner({ handlerFunction: handler });
  });

  beforeEach(() => {
    // Reset state when reusing the same instance
    runner.reset();
  });

  // ... tests
});

Security

See CONTRIBUTING for more information.

License

This project is licensed under the Apache-2.0 License.