@tsed/platform-serverless-http

Platform Serverless Http

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A package of Ts.ED framework. See website: https://tsed.io/tutorials/aws.html

Features

This package allows the creation of a Lambda AWS with an Express.js/Koa.js server.

It supports:

• Mounting Express.js/Koa.js app with serverless-http module,
• DI injection with @tsed/di,
• Models mapping using @tsed/schema and @tsed/json-mapper,
• Params decorators can be used from @tsed/platform-params to get Query, Body, etc...
• Operation descriptions like @Returns,
• @tsed/async-hook-context to inject Context anywhere in your class!

Installation

npm install --save @tsed/platform-serverless-http serverless-http serverless-offline
npm install --save-dev @types/aws-lambda

Configuration

In the src/lambda create a new Lambda class:

import {Controller, Inject} from "@tsed/di";
import {Get, Returns, Summary} from "@tsed/schema";
import {QueryParams} from "@tsed/platform-params";
import {TimeslotsService} from "../services/TimeslotsService";
import {TimeslotModel} from "../models/TimeslotModel";

@Controller("/timeslots")
export class TimeslotsController {
  @Inject()
  protected timeslotsService: TimeslotsService;

  @Get("/")
  @Summary("Return a list of timeslots")
  @Returns(200, Array).Of(TimeslotModel)
  get(@QueryParams("date_start") dateStart: Date, @QueryParams("date_end") dateEnd: Date) {
    return this.timeslotsService.find({
      dateStart,
      dateEnd
    });
  }
}

Create new Server.ts to configure your Ts.ED application:

import {Configuration, Inject} from "@tsed/di";
import {PlatformApplication} from "@tsed/common";
import cors from "cors";
import compress from "compression";
import cookieParser from "cookie-parser";
import methodOverride from "method-override";
import "@tsed/ajv";
import "@tsed/swagger";
import {TimeslotsController} from "./controllers/TimeslotsController";

@Configuration({
  acceptMimes: ["application/json"],
  mount: {
    "/": [TimeslotsController]
  },
  swagger: [
    {
      path: "/v3/docs",
      specVersion: "3.0.1"
    }
  ],
  views: {
    root: "${rootDir}/views",
    extensions: {
      ejs: "ejs"
    }
  },
  middlewares: ["cors", "cookie-parser", "compression", "method-override", "json-parser", "urlencoded-parser"]
})
export class Server {}

Create new handler.ts to expose your lambda:

import {PlatformServerless} from "@tsed/platform-serverless-http";
import {PlatformExpress} from "@tsed/platform-express";
import {Server} from "./Server";

const platform = PlatformServerless.bootstrap(Server, {
  adapter: PlatformExpress
});

export const handler = platform.handler();

Create also index.ts to expose run Ts.ED on you local machine:

import {PlatformExpress} from "@tsed/platform-express";
import {Server} from "./Server";

async function bootstrap() {
  const platform = await PlatformExpress.bootstrap(Server, {
    httpsPort: false,
    httpPort: process.env.PORT || 3000,
    disableComponentsScan: true
  });

  await platform.listen();

  return platform;
}

bootstrap();

Finally, create the serverless.yml:

service: timeslots

frameworkVersion: "2"

provider:
  name: aws
  runtime: nodejs14.x
  lambdaHashingVersion: "20201221"

plugins:
  - serverless-offline

functions:
  any:
    handler: dist/handler.handler
    events:
      - http:
          method: ANY
          path: /
      - http:
          method: ANY
          path: "{proxy+}"

Invoke a lambda with serverless

Serverless provide a plugin named serverless-offline. This Serverless plugin emulates AWS λ and API Gateway on your local machine to speed up your development cycles. To do so, it starts an HTTP server that handles the request's lifecycle like API does and invokes your handlers.

So, by using the serverless offline command, we'll be able to invoke our function. For that, we need also to build our code before invoke the lambda.

To simplify our workflow, we can add the following npm script command in our package.json:

{
  "scripts": {
    "invoke": "yarn serverless invoke local -f any --data '{\"path\":\"/timeslots\", \"httpMethod\": \"GET\"}'"
  }
}

Now, we can run the following command to invoke our lambda:

yarn invoke
// OR
npm run invoke

You should see in the terminal the following result:

{
  "statusCode": 200,
  "body": "[{\"id\":\"b6de4fc7-faaa-4cd7-a144-42f6af0dec6b\",\"title\":\"title\",\"description\":\"description\",\"start_date\":\"2021-10-29T10:40:57.019Z\",\"end_date\":\"2021-10-29T10:40:57.019Z\",\"created_at\":\"2021-10-29T10:40:57.019Z\",\"update_at\":\"2021-10-29T10:40:57.019Z\"}]",
  "headers": {
    "content-type": "application/json",
    "x-request-id": "ebb52d5e-113b-40da-b34e-c14811df596b"
  },
  "isBase64Encoded": false
}

Get Aws Context and Aws Event

This package includes decorators to easily get the event object Lambda received from API Gateway:

import {Controller, Get} from "@tsed/common";
import {ServerlessEvent, ServerlessContext} from "@tsed/platform-serverless-http";

@Controller("/")
class MyCtrl {
  @Get("/")
  get(@ServerlessEvent() event: any, @ServerlessContext() context: ServerlessContext) {
    console.log("Event", event);
    console.log("Context", context);

    return {event, context};
  }
}

Testing

Ts.ED provide a way to test you lambda with mocked Aws event and context by using the @@PlatformServerlessTest@@ util.

Here an example to test a Lambda controller:

import {PlatformServerless} from "@tsed/platform-serverless-http";
import {PlatformServerlessTest} from "@tsed/platform-serverless-testing";
import {PlatformExpress} from "@tsed/platform-express";
import {Server} from "./Server";

@Controller("/timeslots")
class TimeslotsController {
  @Get("/")
  getAll() {
    return [];
  }
}

describe("TimeslotsController", () => {
  beforeEach(
    PlatformServerlessTest.bootstrap(PlatformServerlessHttp, {
      server: Server,
      mount: {
        "/": [TimeslotsLambdaController]
      }
    })
  );
  afterEach(() => PlatformServerlessTest.reset());

  it("should call getAll Lambda", async () => {
    const response = await PlatformServerlessTest.request.get("/timeslots");

    expect(response.statusCode).toEqual(200);
    expect(JSON.parse(response.body)).toEqual([]);
  });
});

Contributors

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License

The MIT License (MIT)

Copyright (c) 2016 - 2022 Romain Lenzotti

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.