fix (datafile management): Clear timeout created in onReady method when it's no longer needed (#272)

Summary:

onReady sets a timeout that fulfills a timeout promise. The timeout promise is only used to race against the ready promise provided by ProjectConfigManager. So, as soon as ProjectConfigManager's ready promise is fulfilled, the timeout can be cleared. Before this change, the timeout would only be cleared in the close method.

Test plan:

Manual & added unit test

Author: mjc1283

packages/optimizely-sdk/CHANGELOG.MD

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 Changes that have landed but are not yet released.
 
+### Bug Fixes:
+- Clear timeout created in onReady call for timeout promise as soon as project config manager's ready promise fulfills
+
 ### New Features
 - Added 60 second timeout for all datafile requests
 

packages/optimizely-sdk/lib/optimizely/index.js

@@ -936,6 +936,14 @@ Optimizely.prototype.onReady = function(options) {
     onClose: onClose,
   };
 
+  this.__readyPromise.then(function() {
+    clearTimeout(readyTimeout);
+    delete this.__readyTimeouts[timeoutId];
+    resolveTimeoutPromise({
+      success: true,
+    });
+  }.bind(this));
+
   return Promise.race([this.__readyPromise, timeoutPromise]);
 };
 

packages/optimizely-sdk/lib/optimizely/index.tests.js

@@ -4831,11 +4831,17 @@ describe('lib/optimizely', function() {
 
     describe('onReady method', function() {
       var clock;
+      var setTimeoutSpy;
+      var clearTimeoutSpy;
       beforeEach(function() {
         clock = sinon.useFakeTimers(new Date().getTime());
+        setTimeoutSpy = sinon.spy(clock, 'setTimeout');
+        clearTimeoutSpy = sinon.spy(clock, 'clearTimeout');
       });
 
       afterEach(function() {
+        setTimeoutSpy.restore();
+        clearTimeoutSpy.restore();
         clock.restore();
       });
 
@@ -4944,6 +4950,32 @@ describe('lib/optimizely', function() {
           return readyPromise3;
         });
       });
+
+      it('clears the timeout when the project config manager ready promise fulfills', function() {
+        projectConfigManager.ProjectConfigManager.callsFake(function(config) {
+          return {
+            stop: sinon.stub(),
+            getConfig: sinon.stub().returns(null),
+            onUpdate: sinon.stub().returns(function() {}),
+            onReady: sinon.stub().returns(Promise.resolve({ success: true })),
+          };
+        });
+        optlyInstance = new Optimizely({
+          clientEngine: 'node-sdk',
+          errorHandler: errorHandler,
+          eventDispatcher: eventDispatcher,
+          jsonSchemaValidator: jsonSchemaValidator,
+          logger: createdLogger,
+          sdkKey: '12345',
+          isValidInstance: true,
+        });
+        return optlyInstance.onReady().then(function() {
+          sinon.assert.calledOnce(clock.setTimeout);
+          var timeout = clock.setTimeout.getCall(0).returnValue;
+          sinon.assert.calledOnce(clock.clearTimeout);
+          sinon.assert.calledWithExactly(clock.clearTimeout, timeout);
+        });
+      });
     });
 
     describe('project config updates', function() {