📦 npm-public

A collection of utility functions published as a public npm package.
Currently includes sendEventToBus, a utility to send cached client-side errors to a central AWS EventBridge observability bus.

⚡ Quick Tips for Local Development

• Test without publishing:

  npm link

• Check publish contents:

  npm pack

📌 Function: sendEventToBus

A lightweight utility to send cached client-side errors to a central AWS EventBridge observability bus.

⚡ Set Up

⚙️ Environment Variables

The following environment variables must be set for sendEventToBus to work:

| Variable | Description | Example | |----------|-------------|---------| | AWS_OBSERVABILITY_EVENT_BUS_ARN | ARN of the AWS EventBridge observability event bus where the event will be sent. | arn:aws:events:eu-central-1:123456789012:event-bus/observability-bus | | AWS_OBSERVABILITY_REGION | AWS region where the observability event bus is deployed. | eu-central-1 | | SERVICE_NAME | Name of the service emitting observability events. | ratgeber-hub-api |

⚙️ serverless.yml: IAM Policy

Make sure your serverless.yml file defines a policy to allow events:PutEvents to the target observability EventBus:

- Effect: Allow
  Action:
    - events:PutEvents
  Resource: ${env:AWS_OBSERVABILITY_EVENT_BUS_ARN}

📦 Installation

npm install @dpa-infocom/observability

🚀 Usage: Middleware (recommended)

The package provides a middleware adapter function called reportErrorMiddleware calls the sendEventToBus function and returns a 500 response object for API Gateway. reportErrorMiddleware will only be triggered if the lambda throws an error that is not handled.

Example:

import { reportErrorMiddleware } from "@dpa-infocom/observability";

const lambdaHandler = async (event: string, context: Context) => {
    throw new Error("Unhandled Error Occurs");
};

export const handler = middy(lambdaHandler)
    .use(reportErrorMiddleware());

Alternative usage

Import the function sendEventToBus directly:

Example:

import { sendEventToBus } from "@dpa-infocom/observability";

async function lambdaHandler(event: string, context: Context) {
  try{
    ...
  } catch(error){
      await sendEventToBus({
        event,
        context,
        error
      });
  }
}
lambdaHandler();