eb-patterns

EventBridge TestEventPattern API - Local

This module provides a local, synchronous implementation of the AWS EventBridge testEventPattern API, allowing to test EventBridge event patterns without the need to hit AWS servers. It's designed to be quick, efficient, and easy to integrate.

Features

• Local Pattern Testing: Test EventBridge patterns synchronously without requiring AWS API calls.
• Easy Integration: Seamlessly integrates with existing Node.js applications.
• Comprehensive Pattern Matching: Supports a wide range of pattern matching features including wildcard, nested field matching, and more.

Installation

npm install eb-patterns

Usage

import { testEventPattern } from 'eb-patterns';

const event = { /* your AWS event JSON string */ };
const pattern = { /* your AWS eventPattern JSON string */ };

/* 
  behaves same like AWS` testEventPattern method
  https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/EventBridge.html#testEventPattern-property
*/
const result = testEventPattern({ Event: event, EventPattern: pattern });

console.log(result); // true or false based on pattern matching

import { testPattern } from 'eb-patterns';

const data = { contact: { name: 'John', age: 30, nationality: 'DE' } };
const pattern = { contact: { name: ['John'], age: [{ numeric: ['>=', 25] } };

// test any patterns
const result = testPattern(data, pattern);

console.log(result); // true or false based on pattern matching

API Reference

testEventPattern(params)

• params: An object that contains the parameters for testEventPattern.
• params.Event: This should resemble an EventBridge event's format. It's a JSON string representing a valid object and must include these properties: id, detail-type, source, account, time, region, detail.
• params.EventPattern: A JSON string that represents a valid JSON object. It must contain all of the following properties: detail

testPattern(data, pattern)

• data: The data object to test.
• pattern: The pattern object against which the event is tested.

Returns true if the event matches the pattern, false otherwise.

Available Patterns

Comparison	Example	Rule syntax
Null	first_name is null	"first_name": [ null ]
Empty	last_name is empty	"last_name": [""]
Equals	email is "[e-mail]"	"email": [ "[e-mail]" ]
Equals (ignore case)	first_name is "John"	"first_name": [ { "equals-ignore-case": "john" } ]
And	fist_name is "John" and last_name is "Doe"	"first_name": [ "John" ], "last_name": ["Doe"]
Or	payment_type is "Invoice" or "SEPA"	"payment_type": [ "invoice", "sepa"]
Or (multiple fields)	first_name is "John", or last_name is "Doe".	"$or": [ { "first_name": [ "John" ] }, { "last_name": [ "Doe" ] } ]
Not	status is anything but "cancelled"	"status": [ { "anything-but": [ "cancelled" ] } ]
Numeric (equals)	price is 100	"price": [ { "numeric": [ "=", 100 ] } ]
Numeric (range)	price is more than 10, and less than or equal to 20	"price": [ { "numeric": [ ">", 10, "<=", 20 ] } ]
Exists	product_name exists	"product_name": [ { "exists": true } ]
Does not exist	product_name does not exist	"product_name": [ { "exists": false } ]
Begins with	product_name starts with PRO-	"product_name": [ { "prefix": "PRO-" } ]
Ends with	filename ends with a .png extension	"filename": [ { "suffix": ".png" } ]
Wildcard	search a string using a wildcard	"email": [ { "wildcard": "*@doe.com" } ]
Wildcard in key	wildcard in the pattern key	"person.*.key": [ { "exists": true } ]