Merge pull request #109 from segmentio/gate-localStorage

feat(ids): add `localStorageFallbackDisabled` flag

Author: f2prateek

lib/entity.js

@@ -144,7 +144,10 @@ Entity.prototype._getIdFromCookie = function() {
  */
 
 Entity.prototype._getIdFromLocalStorage = function() {
-  return store.get(this._options.cookie.key);
+  if (!this._options.localStorageFallbackDisabled) {
+    return store.get(this._options.cookie.key);
+  }
+  return null;
 };
 
 /**
@@ -179,7 +182,9 @@ Entity.prototype._setIdInCookies = function(id) {
  */
 
 Entity.prototype._setIdInLocalStorage = function(id) {
-  store.set(this._options.cookie.key, id);
+  if (!this._options.localStorageFallbackDisabled) {
+    store.set(this._options.cookie.key, id);
+  }
 };
 
 /**

lib/user.js

@@ -100,45 +100,59 @@ User.prototype.anonymousId = function(anonymousId) {
   // set / remove
   if (arguments.length) {
     store.set('ajs_anonymous_id', anonymousId);
-    localStorage.set('ajs_anonymous_id', anonymousId);
+    this._setAnonymousIdInLocalStorage(anonymousId);
     return this;
   }
 
   // new
   anonymousId = store.get('ajs_anonymous_id');
   if (anonymousId) {
-    // value exist in cookie, copy it to localStorage
-    localStorage.set('ajs_anonymous_id', anonymousId);
+    // value exists in cookie, copy it to localStorage
+    this._setAnonymousIdInLocalStorage(anonymousId);
     // refresh cookie to extend expiry
     store.set('ajs_anonymous_id', anonymousId);
     return anonymousId;
   }
 
-  // if anonymousId doesn't exist in cookies, check localStorage
-  anonymousId = localStorage.get('ajs_anonymous_id');
-  if (anonymousId) {
-    // Write to cookies if available in localStorage but not cookies
-    store.set('ajs_anonymous_id', anonymousId);
-    return anonymousId;
+  if (!this._options.localStorageFallbackDisabled) {
+    // if anonymousId doesn't exist in cookies, check localStorage
+    anonymousId = localStorage.get('ajs_anonymous_id');
+    if (anonymousId) {
+      // Write to cookies if available in localStorage but not cookies
+      store.set('ajs_anonymous_id', anonymousId);
+      return anonymousId;
+    }
   }
 
   // old - it is not stringified so we use the raw cookie.
   anonymousId = rawCookie('_sio');
   if (anonymousId) {
     anonymousId = anonymousId.split('----')[0];
     store.set('ajs_anonymous_id', anonymousId);
-    localStorage.set('ajs_anonymous_id', anonymousId);
+    this._setAnonymousIdInLocalStorage(anonymousId);
     store.remove('_sio');
     return anonymousId;
   }
 
   // empty
   anonymousId = uuid.v4();
   store.set('ajs_anonymous_id', anonymousId);
-  localStorage.set('ajs_anonymous_id', anonymousId);
+  this._setAnonymousIdInLocalStorage(anonymousId);
   return store.get('ajs_anonymous_id');
 };
 
+/**
+ * Set the user's `anonymousid` in local storage.
+ *
+ * @param {String} id
+ */
+
+User.prototype._setAnonymousIdInLocalStorage = function(id) {
+  if (!this._options.localStorageFallbackDisabled) {
+    localStorage.set('ajs_anonymous_id', id);
+  }
+};
+
 /**
  * Remove anonymous id on logout too.
  */

test/group.test.js

@@ -57,6 +57,24 @@ describe('group', function() {
       // verify cookie value is retored from localStorage.
       assert.equal(cookie.get(cookieKey), 'gid');
     });
+
+    it('id() should not fallback to localStorage when localStorage fallback is disabled', function() {
+      var group = new Group();
+      group.options({
+        localStorageFallbackDisabled: true
+      });
+
+      group.id('gid');
+
+      // delete the cookie.
+      cookie.remove(cookieKey);
+
+      // verify cookie is deleted.
+      assert.equal(cookie.get(cookieKey), null);
+
+      // verify id() does not return the id when cookie is deleted.
+      assert.equal(group.id(), null);
+    });
   });
 
   describe('#id', function() {
@@ -250,6 +268,16 @@ describe('group', function() {
       assert(store.get(cookieKey) === 'id');
     });
 
+    it('should not save an id to localStorage when localStorage fallback is disabled', function() {
+      group.options({
+        localStorageFallbackDisabled: true
+      });
+
+      group.id('id');
+      group.save();
+      assert.equal(store.get(cookieKey), null);
+    });
+
     it('should save properties to local storage', function() {
       group.properties({ property: true });
       group.save();

test/user.test.js

@@ -57,10 +57,28 @@ describe('user', function() {
       // verify id() returns the id even when cookie is deleted.
       assert.equal(user.id(), 'id');
 
-      // verify cookie value is retored from localStorage.
+      // verify cookie value is restored from localStorage.
       assert.equal(cookie.get(cookieKey), 'id');
     });
 
+    it('id() should not fallback to localStorage when disabled', function() {
+      var user = new User();
+      user.options({
+        localStorageFallbackDisabled: true
+      });
+
+      user.id('id');
+
+      // delete the cookie.
+      cookie.remove(cookieKey);
+
+      // verify cookie is deleted.
+      assert.equal(cookie.get(cookieKey), null);
+
+      // verify id() does not return the id when cookie is deleted.
+      assert.equal(user.id(), null);
+    });
+
     it('should pick the old "_sio" anonymousId', function() {
       rawCookie('_sio', 'anonymous-id----user-id');
       var user = new User();
@@ -345,13 +363,33 @@ describe('user', function() {
         assert.equal(store.get('ajs_anonymous_id'), 'anon0');
       });
 
+      it('should not set anonymousId in localStorage when localStorage fallback is disabled', function() {
+        var user = new User();
+        user.options({
+          localStorageFallbackDisabled: true
+        });
+        user.anonymousId('anon0');
+        assert.equal(cookie.get('ajs_anonymous_id'), 'anon0');
+        assert.equal(store.get('ajs_anonymous_id'), null);
+      });
+
       it('should copy value from cookie to localStorage', function() {
         var user = new User();
         cookie.set('ajs_anonymous_id', 'anon1');
         assert.equal(user.anonymousId(), 'anon1');
         assert.equal(store.get('ajs_anonymous_id'), 'anon1');
       });
 
+      it('should not copy value from cookie to localStorage when localStorage fallback is disabled', function() {
+        var user = new User();
+        user.options({
+          localStorageFallbackDisabled: true
+        });
+        cookie.set('ajs_anonymous_id', 'anon1');
+        assert.equal(user.anonymousId(), 'anon1');
+        assert.equal(store.get('ajs_anonymous_id'), null);
+      });
+
       it('should fall back to localStorage when cookie is not set', function() {
         var user = new User();
 
@@ -365,17 +403,47 @@ describe('user', function() {
         // verify anonymousId() returns the correct id even when there's no cookie
         assert.equal(user.anonymousId(), 'anon12');
 
-        // verify cookie value is retored from localStorage
+        // verify cookie value is restored from localStorage
         assert.equal(cookie.get('ajs_anonymous_id'), 'anon12');
       });
 
+      it('should not fall back to localStorage when cookie is not set and localStorage fallback is disabled', function() {
+        var user = new User();
+        user.options({
+          localStorageFallbackDisabled: true
+        });
+
+        user.anonymousId('anon12');
+        assert.equal(cookie.get('ajs_anonymous_id'), 'anon12');
+
+        // delete the cookie
+        cookie.remove('ajs_anonymous_id');
+        assert.equal(cookie.get('ajs_anonymous_id'), null);
+
+        // verify anonymousId() does not return the id when there's no cookie.
+        assert.notEqual(user.anonymousId(), 'anon12');
+      });
+
       it('should write to both cookie and localStorage when generating a new anonymousId', function() {
         var user = new User();
         var anonId = user.anonymousId();
         assert.notEqual(anonId, null);
         assert.equal(cookie.get('ajs_anonymous_id'), anonId);
         assert.equal(store.get('ajs_anonymous_id'), anonId);
       });
+
+      it('should not write to both cookie and localStorage when generating a new anonymousId and localStorage fallback is disabled', function() {
+        var user = new User();
+        user.options({
+          localStorageFallbackDisabled: true
+        });
+
+        var anonId = user.anonymousId();
+
+        assert.notEqual(anonId, null);
+        assert.equal(cookie.get('ajs_anonymous_id'), anonId);
+        assert.equal(store.get('ajs_anonymous_id'), null);
+      });
     });
   });
 
@@ -463,6 +531,17 @@ describe('user', function() {
       assert.equal(store.get(cookieKey), 'id');
     });
 
+    it('should not save an id to localStorage when localStorage fallback is disabled', function() {
+      user.options({
+        localStorageFallbackDisabled: true
+      });
+      user.id('id');
+
+      user.save();
+
+      assert.equal(store.get(cookieKey), null);
+    });
+
     it('should save traits to local storage', function() {
       user.traits({ trait: true });
       user.save();