add option to pass a stream to pino logger

package.json

@@ -70,6 +70,7 @@
     "prettier": "^1.11.1",
     "promise-retry": "^1.1.1",
     "proxyquire": "^2.0.0",
-    "sinon": "^4.4.2"
+    "sinon": "^4.4.2",
+    "split2": "^2.2.0"
   }
 }

packages/hemera/lib/configScheme.js

@@ -1,5 +1,6 @@
 const Joi = require('joi')
 const Os = require('os')
+const Stream = require('stream').Stream
 const Util = require('./util')
 
 module.exports = Joi.object().keys({
@@ -22,17 +23,20 @@ module.exports = Joi.object().keys({
     .integer()
     .default(0),
   // Custom logger
-  logger: Joi.object()
-    .keys({
-      info: Joi.func().minArity(1),
-      error: Joi.func().minArity(1),
-      debug: Joi.func().minArity(1),
-      fatal: Joi.func().minArity(1),
-      warn: Joi.func().minArity(1),
-      trace: Joi.func().minArity(1),
-      child: Joi.func().minArity(1)
-    })
-    .requiredKeys('info', 'error', 'debug', 'fatal', 'warn', 'trace'),
+  logger: Joi.alternatives().try(
+    Joi.object()
+      .keys({
+        info: Joi.func().minArity(1),
+        error: Joi.func().minArity(1),
+        debug: Joi.func().minArity(1),
+        fatal: Joi.func().minArity(1),
+        warn: Joi.func().minArity(1),
+        trace: Joi.func().minArity(1),
+        child: Joi.func().minArity(1)
+      })
+      .requiredKeys('info', 'error', 'debug', 'fatal', 'warn', 'trace'),
+    Joi.object().type(Stream)
+  ),
   // The error serialization options
   errio: Joi.object()
     .keys({

packages/hemera/lib/index.js

@@ -21,6 +21,7 @@ const TinySonic = require('tinysonic')
 const SuperError = require('super-error')
 const Joi = require('joi')
 const Avvio = require('avvio')
+const Stream = require('stream').Stream
 
 const runExt = require('./extensionRunner').extRunner
 const serverExtIterator = require('./extensionRunner').serverExtIterator
@@ -143,6 +144,8 @@ class Hemera extends EventEmitter {
       DefaultExtensions.onServerPreResponse
     )
 
+    this._configureLogger()
+
     this._avvio = Avvio(this, {
       autostart: false,
       expose: {
@@ -196,34 +199,30 @@ class Hemera extends EventEmitter {
 
       return instance
     }
+  }
 
-    // use own logger
-    if (this._config.logger) {
+  /**
+   *
+   *
+   * @memberof Hemera
+   */
+  _configureLogger() {
+    const loggerOpts = {
+      name: this._config.name,
+      safe: true, // handle circular refs
+      level: this._config.logLevel,
+      serializers: Serializers
+    }
+    if (this._config.logger instanceof Stream) {
+      this.log = Pino(loggerOpts, this._config.logger)
+    } else if (this._config.logger) {
       this.log = this._config.logger
     } else {
-      if (this._config.prettyLog) {
-        let pretty = Pino.pretty()
-        this.log = Pino(
-          {
-            name: this._config.name,
-            safe: true, // avoid error caused by circular references
-            level: this._config.logLevel,
-            serializers: Serializers
-          },
-          pretty
-        )
-
-        // Leads to too much listeners in tests
-        if (this._config.logLevel !== 'silent') {
-          pretty.pipe(process.stdout)
-        }
-      } else {
-        this.log = Pino({
-          name: this._config.name,
-          safe: true,
-          level: this._config.logLevel,
-          serializers: Serializers
-        })
+      const pretty = this._config.prettyLog ? Pino.pretty() : undefined
+      this.log = Pino(loggerOpts, pretty)
+      // Leads to too much listeners in tests
+      if (this._config.logLevel !== 'silent') {
+        pretty.pipe(process.stdout)
       }
     }
   }

test/hemera/logging.spec.js

@@ -1,5 +1,7 @@
 'use strict'
 
+const split = require('split2')
+
 describe('Logging interface', function() {
   var PORT = 6242
   var authUrl = 'nats://localhost:' + PORT
@@ -48,17 +50,18 @@ describe('Logging interface', function() {
 
   it('Should be able to log with default logger', function(done) {
     const nats = require('nats').connect(authUrl)
+    const stream = split(JSON.parse)
     const hemera = new Hemera(nats, {
-      logLevel: 'silent'
+      logLevel: 'info',
+      logger: stream
     })
 
-    var logSpy = Sinon.spy(hemera.log, 'info')
-
-    hemera.log.info('test')
+    stream.once('data', line => {
+      expect(line.msg).to.be.equals('Connected!')
+      hemera.close(done)
+    })
 
-    expect(logSpy.called).to.be.equals(true)
-    logSpy.restore()
-    hemera.close(done)
+    hemera.ready()
   })
 
   it('Should be able to log with none pretty logger', function(done) {
@@ -88,7 +91,7 @@ describe('Logging interface', function() {
     } catch (err) {
       expect(err).to.be.exists()
       expect(err.message).to.be.equals(
-        'child "logger" fails because [child "info" fails because ["info" is required]]'
+        'child "logger" fails because [child "info" fails because ["info" is required], "logger" must be an instance of "Stream"]'
       )
       nats.close()
       done()