diff --git a/test/test_data-test.js b/test/test_data-test.js
index 6779663..8f428a6 100644
--- a/test/test_data-test.js
+++ b/test/test_data-test.js
@@ -222,7 +222,7 @@ describe('TestData', function() {
           {
             "attribute": "name",
             "negate": false,
-            "operator": "in",
+            "op": "in",
             "values":  [
               "ben",
               "christian",
@@ -231,7 +231,7 @@ describe('TestData', function() {
           {
             "attribute": "country",
             "negate": true,
-            "operator": "in",
+            "op": "in",
             "values":  [
               "fr",
             ],
@@ -243,4 +243,33 @@ describe('TestData', function() {
     const clearedRulesFlag = flag.clearRules();
     expect(clearedRulesFlag.build(0)).not.toHaveProperty('rules');
   });
+
+  it('can add evaluate a rule', async function() {
+    const td = TestData();
+    td.update(td.flag('test-flag')
+                   .fallthroughVariation(false)
+                   .ifMatch('name', 'ben', 'christian')
+                   .andNotMatch('country', 'fr')
+                   .thenReturn(true));
+
+    const store = InMemoryFeatureStore();
+    const client = LDClient.init('sdk_key', { featureStore: store, updateProcessor: td, sendEvents: false });
+
+
+    // User1 should pass because matching name and not matching country
+    const user1 = { 'key': 'user1', 'name': 'christian', 'country': 'us' };
+    const eval1 = await client.variationDetail('test-flag', user1, 'default' );
+
+    expect(eval1.value).toEqual(true);
+    expect(eval1.variationIndex).toEqual(0);
+    expect(eval1.reason.kind).toEqual('RULE_MATCH');
+
+    // User2 should NOT pass because matching name but incorrectly matching country
+    const user2 = { 'key': 'user2', 'name': 'ben', 'country': 'fr' };
+    const eval2 = await client.variationDetail('test-flag', user2, 'default' );
+
+    expect(eval2.value).toEqual(false);
+    expect(eval2.variationIndex).toEqual(1);
+    expect(eval2.reason.kind).toEqual('FALLTHROUGH');
+  });
 });
diff --git a/test_data.js b/test_data.js
index 50d72fc..d39aa67 100644
--- a/test_data.js
+++ b/test_data.js
@@ -97,7 +97,7 @@ TestDataFlagBuilder.prototype.copy = function () {
   to._on = this._on;
   to._fallthroughVariation = this._fallthroughVariation;
   to._targets = !this._targets ? null : new Map(this._targets);
-  to._rules = !this._rules ? null : JSON.parse(JSON.stringify(this._rules));
+  to._rules = !this._rules ? null : this._rules.map(r => r.copy(this));
   return to;
 };
 
@@ -259,7 +259,7 @@ function TestDataRuleBuilder(flagBuilder) {
 TestDataRuleBuilder.prototype.andMatch = function (attribute, ...values) {
   this._clauses.push({
     attribute: attribute,
-    operator: 'in',
+    op: 'in',
     values: values,
     negate: false,
   });
@@ -269,7 +269,7 @@ TestDataRuleBuilder.prototype.andMatch = function (attribute, ...values) {
 TestDataRuleBuilder.prototype.andNotMatch = function (attribute, ...values) {
   this._clauses.push({
     attribute: attribute,
-    operator: 'in',
+    op: 'in',
     values: values,
     negate: true,
   });
@@ -295,4 +295,11 @@ TestDataRuleBuilder.prototype.build = function (id) {
   };
 };
 
+TestDataRuleBuilder.prototype.copy = function (flagBuilder) {
+  const flagRuleBuilder = new TestDataRuleBuilder(flagBuilder);
+  flagRuleBuilder._clauses = JSON.parse(JSON.stringify(this._clauses));
+  flagRuleBuilder._variation = JSON.parse(JSON.stringify(this._variation));
+  return flagRuleBuilder;
+};
+
 module.exports = TestData;