(fix): check revision as well in batch event (#258)

* check revision as well

Author: thomaszurkan-optimizely

Sources/Extensions/ArrayEventForDispatch+Extension.swift

@@ -25,6 +25,7 @@ extension Array where Element == EventForDispatch {
         var visitors: [Visitor] = [Visitor]()
         var url: URL?
         var projectId: String?
+        var revision: String?
 
         let checkUrl = { (event: EventForDispatch) -> Bool in
             if url == nil {
@@ -42,11 +43,19 @@ extension Array where Element == EventForDispatch {
             return projectId == batchEvent.projectID
         }
 
+        let checkRevision = { (batchEvent: BatchEvent) -> Bool in
+            if revision == nil {
+                revision = batchEvent.revision
+                return true
+            }
+            return revision == batchEvent.revision
+        }
+
         var firstBatchEvent: BatchEvent?
 
         for event in self {
             if let batchEvent = try? JSONDecoder().decode(BatchEvent.self, from: event.body) {
-                if !checkUrl(event) || !checkProjectId(batchEvent) {
+                if !checkUrl(event) || !checkProjectId(batchEvent) || !checkRevision(batchEvent) {
                     return nil
                 }
                 visitors.append(contentsOf: batchEvent.visitors)

Tests/OptimizelyTests-Common/EventDispatcherTests_Batch.swift

@@ -109,7 +109,7 @@ extension EventDispatcherTests_Batch {
     }
 
     func testBatchingEventsWhenProjectIdsNotEqual() {
-        let be1 = makeTestBatchEvent(projectId: nil, visitor: visitorA)
+        let be1 = makeTestBatchEvent(visitor: visitorA)
         let be2 = makeTestBatchEvent(projectId: "99999", visitor: visitorA)
 
         let events: [EventForDispatch] = [
@@ -120,7 +120,20 @@ extension EventDispatcherTests_Batch {
         let batch = events.batch()
         XCTAssertNil(batch)
     }
-    
+
+    func testBatchingEventsWhenRevisionNotEqual() {
+        let be1 = makeTestBatchEvent(visitor: visitorA)
+        let be2 = makeTestBatchEvent(revision: "99999", visitor: visitorA)
+        
+        let events: [EventForDispatch] = [
+            makeEventForDispatch(url: kUrlA, event: be1),
+            makeEventForDispatch(url: kUrlB, event: be2)
+        ]
+        
+        let batch = events.batch()
+        XCTAssertNil(batch)
+    }
+
 }
 
 // MARK: - FlushEvents
@@ -531,11 +544,12 @@ extension EventDispatcherTests_Batch {
         return EventForDispatch(url: URL(string: url), body: data)
     }
 
-    func makeTestBatchEvent(projectId: String?=nil, visitor: Visitor?=nil) -> BatchEvent {
+    func makeTestBatchEvent(projectId: String?=nil, revision: String?=nil, visitor: Visitor?=nil) -> BatchEvent {
         let testProjectId = projectId ?? kProjectId
         let testVisitor = visitor ?? visitorA
+        let testRevision = revision ?? kRevision
 
-        return BatchEvent(revision: kRevision,
+        return BatchEvent(revision: testRevision,
                           accountID: kAccountId,
                           clientVersion: kClientVersion,
                           visitors: [testVisitor],