feat/df-1026: createLogger() as a singleton

src/index.ts

@@ -1,11 +1,9 @@
 import { getErrorMessage } from '@defra/forms-model'
 
 import { config } from '~/src/config/index.js'
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { createServer } from '~/src/server/index.js'
 
-const logger = createLogger()
-
 process.on('unhandledRejection', (error) => {
   const err = getErrorMessage(error)
   logger.info('Unhandled rejection')

src/server/common/helpers/logging/logger.ts

@@ -2,6 +2,10 @@ import { pino } from 'pino'
 
 import { loggerOptions } from '~/src/server/common/helpers/logging/logger-options.js'
 
-export function createLogger() {
+function createPinoLogger() {
   return pino(loggerOptions)
 }
+
+// Singleton logger instance - pino adds 'exit' listeners to process,
+// so we reuse a single instance to avoid MaxListenersExceededWarning
+export const logger = createPinoLogger()

src/server/common/helpers/redis-client.js

@@ -2,7 +2,7 @@ import { getErrorMessage } from '@defra/forms-model'
 import { Cluster, Redis } from 'ioredis'
 
 import { config } from '~/src/config/index.js'
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 
 /**
  * Setup Redis and provide a redis client
@@ -11,8 +11,6 @@ import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
  * Out in the wild - Elasticache / Redis Cluster with username and password
  */
 export function buildRedisClient() {
-  const logger = createLogger()
-
   const port = 6379
   const db = 0
   const redisConfig = config.get('redis')

src/server/plugins/engine/components/PaymentField.ts

@@ -7,7 +7,7 @@ import {
 import { StatusCodes } from 'http-status-codes'
 import joi, { type ObjectSchema } from 'joi'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { COMPONENT_STATE_ERROR } from '~/src/server/constants.js'
 import { FormComponent } from '~/src/server/plugins/engine/components/FormComponent.js'
 import { type PaymentState } from '~/src/server/plugins/engine/components/PaymentField.types.js'
@@ -40,8 +40,6 @@ import {
   formatCurrency
 } from '~/src/server/plugins/payment/helper.js'
 
-const logger = createLogger()
-
 export class PaymentField extends FormComponent {
   declare options: PaymentFieldComponent['options']
   declare formSchema: ObjectSchema

src/server/plugins/engine/helpers.ts

@@ -15,7 +15,7 @@ import { StatusCodes } from 'http-status-codes'
 import { type Schema, type ValidationErrorItem } from 'joi'
 import { Liquid } from 'liquidjs'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { FORM_VERSION_METADATA_KEY } from '~/src/server/constants.js'
 import {
   getAnswer,
@@ -37,8 +37,6 @@ import {
   type FormResponseToolkit
 } from '~/src/server/routes/types.js'
 
-const logger = createLogger()
-
 export const engine = new Liquid({
   outputEscape: 'escape',
   jsTruthy: true,

src/server/plugins/engine/models/FormModel.ts

@@ -28,7 +28,7 @@ import { add, format } from 'date-fns'
 import { Parser, type Value } from 'expr-eval-fork'
 import joi from 'joi'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { type ListFormComponent } from '~/src/server/plugins/engine/components/ListFormComponent.js'
 import {} from '~/src/server/plugins/engine/components/YesNoField.js'
 import {
@@ -61,8 +61,6 @@ import { FormAction } from '~/src/server/routes/types.js'
 import { merge } from '~/src/server/services/cacheService.js'
 import { type Services } from '~/src/server/types.js'
 
-const logger = createLogger()
-
 export class FormModel {
   /** The runtime engine that should be used */
   engine?: Engine

src/server/plugins/engine/options.js

@@ -1,11 +1,9 @@
 import { getErrorMessage } from '@defra/forms-model'
 import Joi from 'joi'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { CacheService } from '~/src/server/services/index.js'
 
-const logger = createLogger()
-
 const pluginRegistrationOptionsSchema = Joi.object({
   model: Joi.object().optional(),
   services: Joi.object().optional(),

src/server/plugins/engine/routes/payment.js

@@ -2,7 +2,7 @@ import Boom from '@hapi/boom'
 import { StatusCodes } from 'http-status-codes'
 import Joi from 'joi'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { EXTERNAL_STATE_APPENDAGE } from '~/src/server/constants.js'
 import { getPluginOptions } from '~/src/server/plugins/engine/helpers.js'
 import {
@@ -14,8 +14,6 @@ import {
 export const PAYMENT_RETURN_PATH = '/payment-callback'
 export const PAYMENT_SESSION_PREFIX = 'payment-'
 
-const logger = createLogger()
-
 /**
  * Flash form component state after successful payment
  * @param {Request} request - the request

src/server/plugins/map/service.js

@@ -1,11 +1,9 @@
 import { getErrorMessage } from '@defra/forms-model'
 import Boom from '@hapi/boom'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { getJson } from '~/src/server/services/httpService.js'
 
-const logger = createLogger()
-
 /**
  * Returns an empty result set
  */

src/server/plugins/nunjucks/context.js

@@ -5,14 +5,12 @@ import Boom from '@hapi/boom'
 import { StatusCodes } from 'http-status-codes'
 
 import { config } from '~/src/config/index.js'
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import {
   checkFormStatus,
   encodeUrl
 } from '~/src/server/plugins/engine/helpers.js'
 
-const logger = createLogger()
-
 /** @type {Record<string, string> | undefined} */
 let webpackManifest
 

src/server/plugins/payment/service.js

@@ -1,6 +1,6 @@
 import { StatusCodes } from 'http-status-codes'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import {
   buildPaymentInfo,
   convertPenceToPounds
@@ -10,8 +10,6 @@ import { get, post, postJson } from '~/src/server/services/httpService.js'
 const PAYMENT_BASE_URL = 'https://publicapi.payments.service.gov.uk'
 const PAYMENT_ENDPOINT = '/v1/payments'
 
-const logger = createLogger()
-
 /**
  * @param {string} apiKey
  * @returns {{ Authorization: string }}

src/server/plugins/postcode-lookup/service.js

@@ -1,11 +1,9 @@
 import { getErrorMessage } from '@defra/forms-model'
 import Boom from '@hapi/boom'
 
-import { createLogger } from '~/src/server/common/helpers/logging/logger.js'
+import { logger } from '~/src/server/common/helpers/logging/logger.js'
 import { getJson } from '~/src/server/services/httpService.js'
 
-const logger = createLogger()
-
 /**
  * Returns an empty result set
  */