How to debug in VS Code a local AWS Lambda function with API Gateway written in TypeScript?

I wrote a medium article explaining how to create, invoke and debug a TypeScript lambda function. Please for more details check the following link.

Requirements

• SAM CLI
• Docker
• Node
• Visual studio code

1- Create a nodejs12x;

1. Create a nodejs12x lambda;

2. Install TypeScript: npm i -g typescript

3. Initialize typescript: tsc --init (It will create the tsconfig.json file)

4. Replace the created tsconfig.json file with the following code:

   {
   "compilerOptions": {
   "module": "CommonJS",
   "target": "ES2017",
   "noImplicitAny": true,
   "preserveConstEnums": true,
   "outDir": "./built",
   "sourceMap": true
   },
   "include": ["handler/**/*"],
   "exclude": ["node_modules", "**/*.spec.ts"]
   }
   

5. Delete app.js file;

6. Create your lambda in TypeScript code inside of handler folder (you need o create it):

   import { 
    APIGatewayProxyEvent, 
    APIGatewayProxyResult 
   } from "aws-lambda";
   
   export const lambdaHandler = async (
     event: APIGatewayProxyEvent
   ): Promise<APIGatewayProxyResult> => {
     const queries = JSON.stringify(event.queryStringParameters);
     return {
       statusCode: 200,
       body: `Queries: ${queries}`
     }
   }
   

7. Adapt the template.yaml. Change the CodeUri path of your lambda: CodeUri: hello-world/built

8. Install the needed node packages: npm install typescript @types/aws-lambda @types/node -save-dev

9. Package json:

   {
   "name": "typescript_lambda",
   "version": "1.0.0",
   "description": "hello world sample for TypeScript",
   "main": "app.js",
   "repository": "https://github.com/jafreitas90/AWS",
   "author": "Jorge Freitas",
   "license": "JorgeFreitas Ltd :)",
   "dependencies": {
   },
   "scripts": {
     "compile": "tsc"
   },
   "devDependencies": {
     "@types/aws-lambda": "^8.10.71",
     "@types/node": "^14.14.22",
     "aws-sdk": "^2.815.0",
     "typescript": "^4.1.3"
   }
   }
   

10. npm install

11. npm run compile

12. Set a breakpoint in your lambda function (TypeScript code). On the left panel select Debug and then Start debugging (green button on top). And that's it :)

13. Project structure

Please find more details in my tutorial.

source code