Description

Vitest e2e Test for serverless-aws-lambda

Requirements

• serverless-aws-lambda

Installation

yarn add -D serverless-aws-lambda-vitest
# or
npm install -D serverless-aws-lambda-vitest

Recommendations

Some recommendations to speed up Vitest e2e tests by avoiding double bundeling of your Lambdas by Vitest and serverless-aws-lambda.

• Use separate vitest config files for you Unit and e2e test, example:
  • vitest.e2e.config.mts (e2e Test)
  • vitest.ut.config.mts (Unit Test)
• Do not write your End-To-End Tests inside the same (sub) directory as your Lambda handlers
• Specify your e2e Test root directory inside your vitest.e2e.config.mts's include and/or exclude.
• Set vitestPlugin at the end of your defineConfig plugins array.

Usage

use serverless-aws-lambda's defineConfig to import this plugin

// config.ts
import { defineConfig } from "serverless-aws-lambda/defineConfig";
import { vitestPlugin } from "serverless-aws-lambda-vitest";

const test = process.argv.includes("vitest");
const oneshot = process.argv.includes("run");

export default defineConfig({
  plugins: [
    test &&
      vitestPlugin({
        configFile: "./vitest.e2e.config.mts",
        oneshot,
        coverage: {
          outDir: "./coverage/",
          json: true,
          badge: true,
          threshold: 60,
        },
      }),
  ],
});

// vitest.e2e.config.mts
import { defineConfig } from "vitest/config";

export default defineConfig({
  test: {
    include: ["tests/e2e/**/*.test.ts"],
  },
});

Run tests and watch for changes

make sure "sls": "sls" is defined in your package.json > scripts.

yarn sls aws-lambda -s dev vitest
# or
npm run sls -- aws-lambda -s dev vitest

Run tests in CI

yarn sls aws-lambda -s dev vitest run
# or
npm run sls -- aws-lambda -s dev vitest run

Testing async events

The plugin exposes multiple global functions to wait for Lambda handler async invokation responses.

• sqsResponse
• snsResponse
• s3Response
• dynamoResponse

Simple example of implementation for a SQS event:

import { SQSClient, SendMessageCommand } from "@aws-sdk/client-sqs";

const client = new SQSClient({
  region: "eu-west-3",
  endpoint: `http://localhost:${LOCAL_PORT}/@sqs`,
});

const cmd = new SendMessageCommand({
  QueueUrl: "MyQueueName",
  MessageBody: JSON.stringify({
    hello: {
      message: "world",
      firstVisit: true,
    },
  }),
});

test("Single SQS", async () => {
  const res = await client.send(cmd);
  const handlerResponse = await sqsResponse(res.MessageId);
  expect(handlerResponse.success).toBe(true);
});

see more examples.

Coverage

Supported events

• Application Load Balancer (alb)
• API Gateway (http, httpApi)
• DynamoDB Streams
• S3
• SNS
• SQS

Notes

• serverless-aws-lambda's LOCAL_PORT env variable is injected into process.env (also globally if option is enabled in vitest config) of your test files which could be used to make offline request against the local server.
• Set oneshot option to true to launch e2e Tests and exit the process after the first test sequence. Node Process will exit with 0 code, or 1 if Vitest tests fails or coverage threshold is not met.
  • It is also possible to delay exit process by passing {delay: secondes} to oneshot.
• use coverage option to generate coverage result json file and svg badge.