Files
speckle-server/packages/server/modules/shared/services/moduleEventEmitterSetup.ts
T
Iain Sproat 84cb74e8b3 feat(structured logging): implements structured logging for backend (#1217)
* each log line is a json object
* structured logging allows logs to be ingested by machines and the logs to be indexed and queried addresses #1105
* structured logging allows arbitrary properties to be appended to each log line, and ingestion of logs to remain robust
* Structured logging provided by `pino` library
* Add `express-pino-logger` dependency
* Remove `debug`, `morgan`, and `morgan-debug` and replace with structured logging
* `console.log` & `console.error` replaced with structured logging in backend
* Remove `DEBUG` environment variable and replace with `LOG_LEVEL`
- Note that there is a test which reads from a logged line on `stdout`. This is not robust, it would be better to use the childProcess.pid to look up the port number.
* Log errors at points we explicitly send error to Sentry
* Amend indentation of a couple of log messages to align indentation with others
2022-11-25 16:05:05 +00:00

82 lines
2.5 KiB
TypeScript

import { extendLoggerComponent, moduleLogger } from '@/logging/logging'
import { MaybeAsync } from '@/modules/shared/helpers/typeHelper'
import EventEmitter from 'eventemitter2'
export type ModuleEventEmitterParams = {
moduleName: string
/**
* If you have multiple emitters in a single module, you can use this identify
* each of them differently
*/
namespace?: string
}
/**
* Initialize Speckle Module scoped event emitter. These can be used to make code more SOLID - instead of
* modifying some code that does X every time you want to do something extra when X occurs, just emit an event
* there and specify the listening code in a more appropriate module.
*
* Example: Instead of comment mentions being sent out from the comment repository's "createComment" function,
* this repo function emits a COMMENT_CREATED event, that is then handled in a more appropriate module - the speckle
* Notifications module.
*/
export function initializeModuleEventEmitter<P extends Record<string, unknown>>(
params: ModuleEventEmitterParams
) {
const { moduleName, namespace } = params
const identifier = namespace ? `${moduleName}-${namespace}` : moduleName
const logger = extendLoggerComponent(moduleLogger, identifier, 'events')
const errHandler = (e: unknown) => {
logger.error(`Unhandled ${identifier} event emitter error`, e)
}
const emitter = new EventEmitter()
emitter.on('uncaughtException', errHandler)
emitter.on('error', errHandler)
return {
/**
* Emit a module event. This function must be awaited to ensure all listeners
* execute. Any errors thrown in the listeners will bubble up and throw from
* the part of code that triggers this emit() call.
*/
emit: async <K extends keyof P & string>(eventName: K, payload: P[K]) => {
return await emitter.emitAsync(eventName, payload)
},
/**
* Listen for module events. Any errors thrown here will bubble out of where
* emit() was invoked.
*
* @returns Callback for stopping listening
*/
listen: <K extends keyof P & string>(
eventName: K,
handler: (payload: P[K]) => MaybeAsync<void>
) => {
emitter.on(eventName, handler, {
async: true,
promisify: true
})
return () => {
emitter.removeListener(eventName, handler)
}
},
/**
* Destroy event emitter
*/
destroy() {
emitter.removeAllListeners()
},
/**
* Debugger scoped to this module event emitter
*/
logger
}
}