Simplifies writing unit tests for AWS Lambda functions using Node.js.
- Verifies correct handler behavior
- Mocks event types with code
- Works asynchronously
- Supports Promises
- Verifies Node.js runtime version
- AWS X-Ray support [experimental]
- Detects resource leaks [experimental]
- Easily integrates with test frameworks (Mocha and Jasmine)
- Handlers can be loaded and removed after execution
- Lightweight and won't impact performance
- Maps the environment variable
LAMBDA_TASK_ROOTto the application's root - Automatically loads .env files
- Works with Node 10.x, and 12.x
Install via npm.
npm install lambda-tester --save-dev
Lambda handlers with support for callbacks use the typical Node.js asynchronous signature:
exports.handler = function( event, context, callback ) {
callback( null, 'success!' );
}The following example shows a simple case for validating that the Lambda (handler) was called successfully (i.e. callback( null, result ):
const LambdaTester = require( 'lambda-tester' );
const myHandler = require( '../index' ).handler;
describe( 'handler', function() {
it( 'test success', async function() {
await LambdaTester( myHandler )
.event( { name: 'Fred' } )
.expectResult();
});
});If the handler calls callback( err ), then the test will fail.
Additionally, if one wanted to test for failure, then the following code would be used:
const LambdaTester = require( 'lambda-tester' );
const myHandler = require( '../index' ).handler;
describe( 'handler', function() {
it( 'test failure', async function() {
await LambdaTester( myHandler )
.event( { name: 'Unknown' } )
.expectError();
});
});Note: you must either return the LambdaTester instance back to the testing
framework or use the await/async keywords.
Complete documentation can be found in our documentation page.
- vandium - Secures and simplifies AWS Lambda handlers
We'd love to get feedback on how you're using lambda-tester and things we could add to make this tool better. Feel free to contact us at feedback@vandium.io
Starting with version 4.0, lambda-tester supports node versions 10 and higher. If you require support for older versions of node, then use a previous version of lambda-tester.