Merge pull request #42 from launchdarkly/ag/ch2334/warn-against-unknown-custom-even-key

[ch2334] warn against unknown custom event key

Author: apucacao

.gitignore

@@ -2,3 +2,4 @@
 npm-debug.log
 node_modules
 dist
+.idea

src/__tests__/LDClient-test.js

@@ -1,6 +1,8 @@
-var LDClient = require('../index');
 var semverCompare = require('semver-compare');
 
+var LDClient = require('../index');
+var messages = require('../messages');
+
 describe('LDClient', function() {
   var xhr;
   var requests = [];
@@ -131,6 +133,72 @@ describe('LDClient', function() {
         }, 1);
       });
     });
+
+    it('should not warn when tracking an known custom goal event', function(done) {
+      var user = {key: 'user'};
+      var client = LDClient.initialize('UNKNOWN_ENVIRONMENT_ID', user, {
+        bootstrap: {} // so the client doesn't request settings
+      });
+
+      var warnSpy = sinon.spy(console, 'warn');
+
+      requests[0].respond(
+        200,
+        { 'Content-Type': 'application/json' },
+        '[{"key": "known", "kind": "custom"}]'
+      );
+
+      client.on('ready', function() {
+        client.track('known');
+        expect(warnSpy.calledWith('Custom event key does not exist')).to.be.false;
+        warnSpy.restore();
+        done();
+      });
+    });
+
+    it('should throw when tracking a non-string custom goal event', function(done) {
+      var user = {key: 'user'};
+      var client = LDClient.initialize('UNKNOWN_ENVIRONMENT_ID', user, {
+        bootstrap: {} // so the client doesn't request settings
+      });
+
+      const track = function(key) {
+        return function() {
+          client.track(key);
+        };
+      };
+
+      client.on('ready', function() {
+        expect(track(123)).to.throw(messages.invalidKey());
+        expect(track([])).to.throw(messages.invalidKey());
+        expect(track({})).to.throw(messages.invalidKey());
+        expect(track(null)).to.throw(messages.invalidKey());
+        expect(track(undefined)).to.throw(messages.invalidKey());
+        done();
+      });
+    });
+
+    it('should warn when tracking an unknown custom goal event', function(done) {
+      var user = {key: 'user'};
+      var client = LDClient.initialize('UNKNOWN_ENVIRONMENT_ID', user, {
+        bootstrap: {} // so the client doesn't request settings
+      });
+
+      var warnSpy = sinon.spy(console, 'warn');
+
+      requests[0].respond(
+        200,
+        { 'Content-Type': 'application/json' },
+        '[{"key": "known", "kind": "custom"}]'
+      );
+
+      client.on('ready', function() {
+        client.track('unknown');
+        expect(warnSpy.calledWith(messages.unknownCustomEventKey('unknown'))).to.be.true;
+        warnSpy.restore();
+        done();
+      });
+    });
   });
 
 });

src/index.js

@@ -5,6 +5,7 @@ var Stream = require('./Stream');
 var Requestor = require('./Requestor');
 var Identity = require('./Identity');
 var utils = require('./utils');
+var messages = require('./messages');
 
 var flags = {};
 var environment;
@@ -113,9 +114,26 @@ function allFlags() {
   return results;
 }
 
+function customEventExists(key) {
+  if (!goals || goals.length === 0) { return false; }
+
+  for (var i=0 ; i < goals.length ; i++) {
+    if (goals[i].kind === 'custom' && goals[i].key === key) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 function track(key, data) {
   if (typeof key !== 'string') {
-    throw 'Event key must be a string';
+    throw messages.invalidKey();
+  }
+
+  // Validate key if we have goals
+  if (!!goals && !customEventExists(key)) {
+    console.warn(messages.unknownCustomEventKey(key));
   }
 
   events.enqueue({

src/messages.js

@@ -0,0 +1,8 @@
+module.exports ={
+  invalidKey: function() {
+    return 'Event key must be a string';
+  },
+  unknownCustomEventKey: function(key) {
+    return 'Custom event "' + key + '" does not exist'
+  }
+};