fix: send empty events packages if all non statisfying condition

.github/workflows/format.yml

@@ -1,4 +1,4 @@
-name: Format
+name: SwiftFormat
 on:
   push:
     branches: [master]

Sources/InstantSearchInsights/Logic/EventProcessor.swift

@@ -159,6 +159,11 @@ private extension EventProcessor {
 
     let eligibleEvents = eventsPackage.items.filter(acceptEvent)
 
+    guard !eligibleEvents.isEmpty else {
+      logger.info("all events in package were filtered out by the acceptance condition, no event will be sent")
+      return
+    }
+
     service.sendEvents(eligibleEvents) { [weak self] result in
 
       guard let processor = self else { return }

Tests/InstantSearchInsightsTests/Unit/EventsProcessorTests.swift

@@ -218,4 +218,36 @@ class EventsProcessorTests: XCTestCase {
 
     waitForExpectations(timeout: 10, handler: nil)
   }
+
+  func testEventsFilteringException() throws {
+    let mockService = MockEventService<Int>()
+    let packageCapacity = 10
+    let queue = DispatchQueue(label: "test queue")
+
+    let storage = TestPackageStorage<Int>()
+    storage.store([try .init(items: [1, 2], capacity: 2), try .init(items: [3, 4], capacity: 2)])
+
+    let acceptEvent: (Int) -> Bool = { _ in false }
+
+    let eventsProcessor = EventProcessor(service: mockService,
+                                         storage: storage,
+                                         packageCapacity: packageCapacity,
+                                         flushNotificationName: nil,
+                                         flushDelay: 1000,
+                                         acceptEvent: acceptEvent,
+                                         logger: Logger(label: #function),
+                                         dispatchQueue: queue)
+
+    let exp = expectation(description: "send events")
+    exp.isInverted = true
+
+    mockService.didSendEvents = { events in
+      XCTAssertTrue(events.allSatisfy(acceptEvent))
+      exp.fulfill()
+    }
+
+    eventsProcessor.flush()
+
+    waitForExpectations(timeout: 10, handler: nil)
+  }
 }