From fc10a115ab9c87db4fa532043b0e3966f847a69f Mon Sep 17 00:00:00 2001
From: Nora <nora.abdelgadir@ibm.com>
Date: Fri, 2 Aug 2019 17:01:28 -0400
Subject: [PATCH] test: add test for getMaxOfflineRequests

---
 lib/datasource.js       | 16 ++++++++++++----
 test/datasource.test.js | 24 ++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/lib/datasource.js b/lib/datasource.js
index e47559ff6..f5f647f29 100644
--- a/lib/datasource.js
+++ b/lib/datasource.js
@@ -194,6 +194,11 @@ util.inherits(DataSource, EventEmitter);
 // allow child classes to supply a data access object
 DataSource.DataAccessObject = DataAccessObject;
 
+/**
+ * Global maximum number of event listeners
+ */
+DataSource.prototype.DEFAULT_MAX_OFFLINE_REQUESTS = 16;
+
 /**
  * Set up the connector instance for backward compatibility with JugglingDB schema/adapter
  * @private
@@ -209,7 +214,6 @@ DataSource.prototype._setupConnector = function() {
     const dataSource = this;
 
     // Set max listeners to a default/configured value
-    // solves bug https://github.com/strongloop/loopback-next/issues/2198
     dataSource.setMaxListeners(dataSource.getMaxOfflineRequests());
 
     this.connector.log = function(query, start) {
@@ -2711,9 +2715,13 @@ DataSource.prototype.getMaxOfflineRequests = function() {
   // Set max listeners to a default value
   // Override this default value with a datasource setting
   // 'maxOfflineRequests' from an application's datasources.json
-  // solves bug https://github.com/strongloop/loopback-next/issues/2198
-  let maxOfflineRequests = 16;
-  if (this.settings && this.settings.maxOfflineRequests) {
+
+  let maxOfflineRequests = this.DEFAULT_MAX_OFFLINE_REQUESTS;
+  if (
+    this.settings &&
+    this.settings.maxOfflineRequests &&
+    typeof this.settings.maxOfflineRequests === 'number'
+  ) {
     if (this.settings.maxOfflineRequests > maxOfflineRequests)
       maxOfflineRequests = this.settings.maxOfflineRequests;
   }
diff --git a/test/datasource.test.js b/test/datasource.test.js
index a3795cd66..ae158506c 100644
--- a/test/datasource.test.js
+++ b/test/datasource.test.js
@@ -545,6 +545,30 @@ describe('DataSource', function() {
       ds.connector.should.equal(connector);
     });
   });
+
+  describe('getMaxOfflineRequests', () => {
+    let ds;
+    beforeEach(() => ds = new DataSource('ds', {connector: 'memory'}));
+
+    it('sets the default maximum number of event listeners to 16', () => {
+      ds.getMaxOfflineRequests().should.be.eql(16);
+    });
+
+    it('uses the default max number of event listeners if the provided one is less than 16', () => {
+      ds.settings.maxOfflineRequests = 15;
+      ds.getMaxOfflineRequests().should.be.eql(16);
+    });
+
+    it('uses provided number of listeners if it is greater than 16', () => {
+      ds.settings.maxOfflineRequests = 17;
+      ds.getMaxOfflineRequests().should.be.eql(17);
+    });
+
+    it('uses default if a non-number is provided for the max number of listeners', () => {
+      ds.settings.maxOfflineRequests = '17';
+      ds.getMaxOfflineRequests().should.be.eql(16);
+    });
+  });
 });
 
 function givenMockConnector(props) {