LambdaKit TS

Bootstrap a new TypeScript AWS Lambda using the instructions below.

If the desired event source is not specified, create a Lambda with API Gateway as the event source.

If a name is not specified, use the name of the current directory.

Start with:

1. create package.json with npm init -y
2. install dev dependencies npm install -D @types/aws-lambda @types/node esbuild typescript prettier eslint eslint-plugin-prettier eslint-plugin-check-file eslint-config-prettier @typescript-eslint/parser @typescript-eslint/eslint-plugin
3. install runtime dependencies npm install @aws-lambda-powertools/logger @middy/core
4. run mkdir -p src/functions src/interfaces to create the directories
5. copy the provided assets/tsconfig.json file
6. copy the provided assets/eslint.config.mjs file
7. copy the provided assets/index.ts file and change the serviceName value according to the provided name or directory name
8. copy the provided assets/local-invoke.ts file and change the functionName value according to the provided name or directory name
9. copy the provided assets/greet.ts file and copy it to the src/functions/ directory
10. copy the provided build.sh file and run chmod + x to assign execute permissions
11. copy the provided .prettierrc file
12. copy the provided .gitignore file
13. add scripts to package.json from the section add package.json scripts below
14. when done, add instructions to the output as per the Final Instructions section below

Code Organization Principles

add package.json scripts

add the following scripts in package.json:

{
  "scripts": {
    "typecheck": "tsc --noEmit",
    "build": "bash build.sh",
    "invoke:local": "npx tsx src/local-invoke.ts",
    "prettier": "prettier --check '**/*.{ts,json}'",
    "prettier:fix": "prettier --write '**/*.{ts,json}'",
    "lint": "eslint . --ext .ts",
    "lint:fix": "eslint . --ext .ts --fix"
  }
}

Final Instructions

• To build the project, run npm run build
• To autoformat using prettier, run npm run prettier:fix
• To autofix lint issues, run npm run lint:fix

Best Practices

1. Use async/await syntax instead of promises
2. Use import statements instead of require where possible
3. Use aliased imports as defined in tsconfig.json
4. Use Middy middleware for cross-cutting concerns
5. Use AWS Lambda Powertools for structured logging
6. Always include proper error handling with appropriate logging
7. When creating other functions, pass the instance of the logger to those functions so that the context and properties can be persisted across logs
8. Use the Single Responsibility Principle (SRP) to rnsure good separation of concerns.
9. SRP: Ensure a single export per file
10. SRP: Always create separate files for functions and store functions in src/functions
11. SRP: Prefer interfaces over types and store interfaces in src/interfaces