Introduction#

GitHub this project shows basics of developing on AWS using TypeScript

  • Setup AWS SDK with TypeScript
  • Basic concepts: Interface, Deconstruct, Enum
  • Experiment S3Client
  • Experiment PollyClient

Setup Project#

Init a new nodejs project as normal

npm init

Then install the typesript complier tsc for this project only

npm install typescript --save-dev

Double check the tsc version

npx tsc --version

Install ambient Node.js types for typescript

npm install @types/node --save-dev

Create a tsconfig.json file

{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "lib": ["es6"],
    "allowJs": true,
    "outDir": "build",
    "rootDir": "src",
    "strict": true,
    "noImplicitAny": true,
    "esModuleInterop": true,
    "resolveJsonModule": true
  }
}

Finally create a simple project structure as the following

|--build
   |--index.js
|--src
   |--index.ts
|--node_modules
|--tsconfig.json
|--package.json
|--package-lock.json

Please take note the package.json

{
  "name": "aws-sdk-typescript-demo",
  "version": "1.0.0",
  "description": "--- author: haimtran date: 01 JUNE 2023 ---",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@types/node": "^20.2.5",
    "typescript": "^5.1.3"
  },
  "dependencies": {
    "@aws-sdk/client-s3": "^3.344.0"
  }
}

S3 Client#

Create a simple S3 Client

const s3Client = new S3Client({
  region: "us-east-1",
});


// desconstruct input
const listObject = async ({ bucketName }: { bucketName: string }) => {
  try {
    const res = await s3Client.send(
      new ListObjectsCommand({
        Bucket: bucketName,
      })
    );


    console.log(res);
  } catch (error) {
    console.log(error);
  }
};


listObject({ bucketName: "cdk-entest-videos" });

Polly Client#

Import to the Polly Client

import { PollyClient, SynthesizeSpeechCommand } from "@aws-sdk/client-polly";

Create Polly Client

const pollyClient = new PollyClient({
  region: "ap-southeast-1",
});

Synthesize speech from text

const synthesizeSpeed = async ({ message }: { message: string }) => {
  const response = await pollyClient.send(
    new SynthesizeSpeechCommand({
      Engine: "standard",
      LanguageCode: "en-US",
      OutputFormat: "mp3",
      Text: message,
      VoiceId: "Amy",
    })
  );


  console.log("audio stream ", response.AudioStream);


  // save audio stream to mp3 file
  const audio = await response.AudioStream?.transformToByteArray();


  if (audio?.buffer) {
    fs.writeFileSync("hello.mp3", Buffer.from(audio.buffer));
  } else {
    console.log("error audio buffer");
  }


  // TODO: write to S3 and get pre-signed url


  if (response.AudioStream) {
    const blob = new Blob([response.AudioStream as Blob]);
    const url = URL.createObjectURL(blob);
    console.log(url);
  }
};

TODO:

  • Write the Audio Stream to S3
  • Serve the Audio Stream right in the browser

Reference#