@nexckycort/lambda-devkit NPM

Lambda DevKit

A development toolkit for compiling and running AWS Lambda functions locally with API Gateway simulation.

Features

Local Execution: Run your AWS Lambda functions locally without deploying to AWS.
API Gateway Simulation: Simulate API Gateway routes and methods (e.g., GET, POST, PUT, DELETE).
Compilation Support: Automatically compile TypeScript or JavaScript Lambda functions.
Flexible Configuration: Define routes, handlers, and environment variables in a simple configuration file.
Developer-Friendly CLI: Use the ldk command to manage and test your Lambda functions.

Installation

Install the package as a project dependency:

pnpm add @nexckycort/lambda-devkit -D

Quick Start

Create a Configuration File
Create a file named lambda-devkit.config.ts in the root of your project. Here's an example configuration:

import type { LambdaDevkitConfig } from '@nexckycort/lambda-devkit';

const config: LambdaDevkitConfig = {
  server: {
    routes: [
      {
        method: 'GET',
        path: 'users',
        lambda: {
          handler: 'functions/getUsers',
          timeout: 5000,
        },
      },
      {
        method: 'POST',
        path: 'users',
        lambda: {
          handler: 'functions/createUser',
          timeout: 10000,
        },
      },
    ],
    port: 4000,
    environment: {
      ENV: 'dev',
    },
  },
  build: {
    bundle: true,
    minify: true,
    external: ['@aws-sdk/*'],
  },
};

export default config;

Start the Local Server
Run the following command to start the local server:
```
ldk dev
```
Test Your Endpoints
Use tools like Postman or curl to test your endpoints:
```
curl http://localhost:4000/users
```

Usage

Commands

The ldk CLI provides the following commands:

Command	Description
`ldk dev`	Start the local server with API Gateway simulation.
`ldk build`	Compile your Lambda functions.

Example

Here’s an example of how to use the CLI:

# Build your Lambda functions
ldk build

# Start the local server
ldk dev

Configuration

Lambda DevKit uses a configuration file (lambda-devkit.config.ts) to define routes, handlers, and other settings. Below is a detailed explanation of each field:

`server`

Server configuration for local development.

Field	Type	Description
`routes`	`RouteConfig[]`	List of routes and their configurations.
`port`	`number`	Port on which the local server will run. Default: `4000`.
`environment`	`object`	Environment variables to be passed to the Lambda function.

`routes`

An array of route configurations. Each route maps an HTTP method and path to a Lambda function.

Field	Type	Description
`method`	`string`	HTTP method (e.g., `GET`, `POST`, `PUT`, `DELETE`).
`path`	`string`	Path for the route. Supports wildcards like `users/*`.
`lambda`	`LambdaConfig`	Configuration for the Lambda function that handles requests to this route.

`lambda`

Configuration for a Lambda function.

Field	Type	Description
`handler`	`string`	Path to the folder containing the Lambda handler (e.g., `functions/myFunction`).
`timeout`	`number`	Maximum execution time for the Lambda function in milliseconds.

`build`

Build configuration for the Lambda functions.

Field	Type	Description
`entryPoint`	`string`	Entry point for the build process. Default: `"functions/**"`.
`bundle`	`boolean`	Whether to bundle the Lambda function code into a single file.
`minify`	`boolean`	Whether to minify the Lambda function code during the build process.
`sourcemap`	`boolean \\| string`	Sourcemap generation options (`true`, `'linked'`, `'inline'`, etc.).
`outbase`	`string`	Base directory for resolving entry points. Default: `"functions"`.
`external`	`string[]`	External libraries that should be excluded from the build. Default: `["@aws-sdk/*"]`.

Examples

Basic Example

Here’s a simple example of a Lambda function and its configuration:

`src/getUsers/index.ts`

export const handler = async (event: any) => {
  console.log("Event:", event);

  return {
    statusCode: 200,
    body: JSON.stringify([
      { id: 1, name: "Alice" },
      { id: 2, name: "Bob" },
    ]),
  };
};

`lambda-devkit.config.ts`

import type { LambdaDevkitConfig } from '@nexckycort/lambda-devkit';

const config: LambdaDevkitConfig = {
  server: {
    routes: [
      {
        method: 'GET',
        path: 'users',
        lambda: {
          handler: 'functions/getUsers'
        },
      },
    ],
    port: 4000,
  },
  build: {
    bundle: true,
    minify: true,
    external: ['@aws-sdk/*'],
  },
};

export default config;

Run the server: