@runnel/metric-plugin

To verify publisher/subscriber calls, use @runnel/metric-plugin which collects six types of data:

1. schema - The schema of the topic.
2. onCreateTopic: The number of the topic created.
3. lastPayload: The latest payload to the topic.
4. onPostMessage: The number of the topic published.
5. onAddEventListener: The number of the topic subscribed to.
6. onRemoveEventListener: The number of the topic unsubscribed from.

Usage

import { createPlugin, type Metrics } from "@runnel/metric-plugin";
import { runnel } from "runneljs";

const { register, observer } = createPlugin(deepEqual);
const eventBus = runnel("my-event-bus", deepEqual, validator);
register();

...

// Example with React.useState
const [metrics, setMetrics] = useState<Metrics>();
observer.subscribe(setMetrics);

Find more usage example on the Guides page.

Output Examples

Case 1

• topic1 with schema { "type": "number" }.
• No subscribers.
• One publish event with payload 100.

{
  "topic1": {
    "schema": { "type": "number" },
    "onCreateTopic": 1,
    "lastPayload": 100,
    "onPostMessage": 1,
    "onAddEventListener": 0,
    "onRemoveEventListener": 0
  }
}

Case 2

• topic2 with schema { "type": "string" }.
• One subscriber.
• No publish events.

{
  "topic2": {
    "schema": { "type": "string" },
    "onCreateTopic": 1,
    "lastPayload": null,
    "onPostMessage": 0,
    "onAddEventListener": 1,
    "onRemoveEventListener": 0
  }
}