diff --git a/test/PhasedRollOut-test.js b/test/PhasedRollOut-test.js
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+++ b/test/PhasedRollOut-test.js
@@ -0,0 +1,75 @@
+/*
+Copyright 2018 New Vector Ltd
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import expect from 'expect';
+import {phasedRollOutExpiredForUser} from '../src/PhasedRollOut';
+
+const OFFSET = 6000000;
+// phasedRollOutExpiredForUser enables users in bucks of 1 minute
+const MS_IN_MINUTE = 60 * 1000;
+
+describe('PhasedRollOut', function() {
+    it('should return true if phased rollout is not configured', function() {
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test", 0, null)).toBeTruthy();
+    });
+
+    it('should return true if phased rollout feature is not configured', function() {
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test", 0, {
+            "feature_other": {offset: 0, period: 0}
+        })).toBeTruthy();
+    });
+
+    it('should return false if phased rollout for feature is misconfigured', function() {
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test", 0, {
+            "feature_test": {}
+        })).toBeFalsy();
+    });
+
+    it("should return false if phased rollout hasn't started yet", function() {
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test", 5000000,{
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE}
+        })).toBeFalsy();
+    });
+
+    it("should start to return true in bucket 2/10 for '@user:hs'", function() {
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test",
+            OFFSET + (MS_IN_MINUTE * 2) - 1, {
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE * 10}
+        })).toBeFalsy();
+        expect(phasedRollOutExpiredForUser("@user:hs", "feature_test",
+            OFFSET + (MS_IN_MINUTE * 2), {
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE * 10}
+        })).toBeTruthy();
+    });
+
+    it("should start to return true in bucket 4/10 for 'alice@other-hs'", function() {
+        expect(phasedRollOutExpiredForUser("alice@other-hs", "feature_test",
+            OFFSET + (MS_IN_MINUTE * 4) - 1, {
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE * 10}
+        })).toBeFalsy();
+        expect(phasedRollOutExpiredForUser("alice@other-hs", "feature_test",
+            OFFSET + (MS_IN_MINUTE * 4), {
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE * 10}
+        })).toBeTruthy();
+    });
+
+    it("should return true after complete rollout period'", function() {
+        expect(phasedRollOutExpiredForUser("user:hs", "feature_test",
+            OFFSET + (MS_IN_MINUTE * 20), {
+            "feature_test": {offset: OFFSET, period: MS_IN_MINUTE * 10}
+        })).toBeTruthy();
+    });
+
+
+
+});