@nikovirtala/projen-bundle-lambda-function-code

A Projen component for automatically bundling AWS Lambda function code using esbuild.

Features

- Auto-discovery: Automatically finds Lambda handler files with configurable extensions
- ESBuild bundling: Uses esbuild for fast, efficient bundling
- CDK integration: Generates CDK constructs with pre-bundled Lambda code
- TypeScript support: Full TypeScript support with configurable tsconfig
- Flexible configuration: Customizable bundling options per function

Installation

``bash
npm install @nikovirtala/projen-bundle-lambda-function-code
`

Usage

$3

Add the bundler to your Projen TypeScript project:

`typescript
import { LambdaFunctionCodeBundler, Bundler } from '@nikovirtala/projen-bundle-lambda-function-code';

const project = new typescript.TypeScriptProject({
// ... your project config
});

// Add the bundler component
new Bundler(project);

// Auto-discover and bundle Lambda functions
new LambdaFunctionCodeBundler(project, {
extension: '.lambda.ts',
srcdir: 'src',
});
`

$3

Create Lambda handler files with the configured extension:

`typescript
// src/hello-world.lambda.ts
export const handler = async (event: any) => {
return {
statusCode: 200,
body: JSON.stringify({ message: 'Hello World!' }),
};
};
`

$3

The bundler automatically generates CDK constructs for each Lambda function:

`typescript
// Generated: src/hello-world-code.ts
import * as path from 'path';
import { aws_lambda } from 'aws-cdk-lib';

export const HelloWorldFunctionCode = aws_lambda.Code.fromAsset(
path.join(__dirname, '../assets/hello-world'),
);
`

Use in your CDK stack:

`typescript
import { HelloWorldFunctionCode } from './hello-world-code';

new aws_lambda.Function(this, 'HelloWorldFunction', {
runtime: aws_lambda.Runtime.NODEJS_20_X,
handler: 'index.handler',
code: HelloWorldFunctionCode,
});
`

API Reference

$3

Main component for esbuild bundling support.

`typescript
new Bundler(project, {
esbuildVersion?: string; // esbuild version requirement
assetsDir?: string; // output directory (default: "assets")
addToPreCompile?: boolean; // add to pre-compile phase (default: true)
loaders?: Record; // file extension loaders
});
`

$3

Auto-discovers and bundles Lambda functions.

`typescript
new LambdaFunctionCodeBundler(project, {
extension: string; // file extension to discover (e.g., ".lambda.ts")
srcdir: string; // source directory to scan
bundleOptions?: { // default bundling options
externals?: string[];
sourcemap?: boolean;
target?: string;
platform?: string;
// ... more options
};
});
`

$3

Bundle individual Lambda functions.

`typescript
new LambdaFunctionCodeBundle(project, {
entrypoint: string; // path to Lambda handler file
extension: string; // file extension
constructFile?: string; // generated construct file name
constructName?: string; // generated construct class name
bundlingOptions?: BundlingOptions;
});
`

Bundling Options

Customize esbuild behavior:

`typescript
interface BundlingOptions {
externals?: string[]; // external dependencies to exclude
sourcemap?: boolean; // include source maps (default: true)
target?: string; // esbuild target (default: "esnext")
platform?: string; // target platform (default: "node")
outfile?: string; // output filename (default: "index.mjs")
format?: string; // output format (esm, cjs, iife)
minify?: boolean; // minify output (default: true)
tsconfigPath?: string; // TypeScript config path
loaders?: Record; // file loaders
}
`

Examples

$3

`typescript
new LambdaFunctionCodeBundler(project, {
extension: '.lambda.ts',
srcdir: 'src/functions',
bundleOptions: {
externals: ['aws-sdk'],
minify: false,
sourcemap: true,
target: 'node18',
},
});
`

$3

`typescript
new LambdaFunctionCodeBundle(project, {
entrypoint: 'src/special-function.lambda.ts',
extension: '.lambda.ts',
constructName: 'SpecialFunction',
bundlingOptions: {
externals: ['@aws-sdk/client-s3'],
format: 'cjs',
},
});
`

Development

This project uses Projen for configuration management.

`bash


Install dependencies

pnpm install

Build the project

pnpm build

Run tests

pnpm test

Update project configuration

npx projen
``

License

MIT