maxQueueSize wasn't respected when capturing events

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Next
 
+- `maxQueueSize` wasn't respected when capturing events [#116](https://github.com/PostHog/posthog-ios/pull/116)
+
 ## 3.2.3 - 2024-03-05
 
 - `optOut` wasn't respected in capture methods [#114](https://github.com/PostHog/posthog-ios/pull/114)

PostHog/PostHogQueue.swift

@@ -168,6 +168,12 @@ class PostHogQueue {
     }
 
     func add(_ event: PostHogEvent) {
+        if fileQueue.depth >= config.maxQueueSize {
+            hedgeLog("Queue is full, dropping oldest event")
+            // first is always oldest
+            fileQueue.delete(index: 0)
+        }
+
         var data: Data?
         do {
             data = try JSONSerialization.data(withJSONObject: event.toJSON())

PostHogTests/PostHogQueueTest.swift

@@ -12,9 +12,10 @@ import Quick
 import XCTest
 
 class PostHogQueueTest: QuickSpec {
-    func getSut() -> PostHogQueue {
+    func getSut(flushAt: Int = 1, maxQueueSize: Int = 1000) -> PostHogQueue {
         let config = PostHogConfig(apiKey: "123", host: "http://localhost:9001")
-        config.flushAt = 1
+        config.flushAt = flushAt
+        config.maxQueueSize = maxQueueSize
         let storage = PostHogStorage(config)
         let api = PostHogApi(config)
         return PostHogQueue(config, storage, api, nil)
@@ -64,5 +65,31 @@ class PostHogQueueTest: QuickSpec {
 
             sut.clear()
         }
+
+        it("add item to queue and rotate queue") {
+            let sut = self.getSut(flushAt: 3, maxQueueSize: 2)
+
+            let event = PostHogEvent(event: "event", distinctId: "distinctId")
+            let event2 = PostHogEvent(event: "event2", distinctId: "distinctId2")
+            let event3 = PostHogEvent(event: "event3", distinctId: "distinctId3")
+            sut.add(event)
+            sut.add(event2)
+            sut.add(event3)
+
+            expect(sut.depth) == 2
+
+            sut.flush()
+
+            let events = getBatchedEvents(server)
+
+            expect(events.count) == 2
+
+            let first = events.first!
+            let last = events.last!
+            expect(first.event) == "event2"
+            expect(last.event) == "event3"
+
+            sut.clear()
+        }
     }
 }