Merge pull request #2154 from DataDog/maciey/RUM-7205/double-full-snapshot-bug

RUM-7205 Double full snapshot bug

Co-authored-by: maciejburda <maciej.burda@datadoghq.com>

Author: dd-mergequeue[bot]

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 - [IMPROVEMENT] Add Datadog Configuration `backgroundTasksEnabled` ObjC API. See [#2148][]
+- [FIX] Prevent Session Replay to create two full snapshots in a row. See [#2154][]
 
 # 2.21.0 / 11-12-2024
 
@@ -809,6 +810,7 @@ Release `2.0` introduces breaking changes. Follow the [Migration Guide](MIGRATIO
 [#2120]: https://github.com/DataDog/dd-sdk-ios/pull/2120
 [#2126]: https://github.com/DataDog/dd-sdk-ios/pull/2126
 [#2148]: https://github.com/DataDog/dd-sdk-ios/pull/2148
+[#2154]: https://github.com/DataDog/dd-sdk-ios/pull/2154
 [@00fa9a]: https://github.com/00FA9A
 [@britton-earnin]: https://github.com/Britton-Earnin
 [@hengyu]: https://github.com/Hengyu

DatadogSessionReplay/Sources/Processor/Builders/RecordsBuilder.swift

@@ -66,9 +66,6 @@ internal class RecordsBuilder {
     /// In case of unexpected failure, it will fallback to creating FSR instead.
     /// If the root wireframe has changed, we trigger a full snapshot so it is added first in the replay.
     func createIncrementalSnapshotRecord(from snapshot: ViewTreeSnapshot, with wireframes: [SRWireframe], lastWireframes: [SRWireframe]) -> SRRecord? {
-        if wireframes.first?.id != lastWireframes.first?.id {
-            return createFullSnapshotRecord(from: snapshot, wireframes: wireframes)
-        }
         do {
             return try createIncrementalSnapshotRecord(from: snapshot, newWireframes: wireframes, lastWireframes: lastWireframes)
         } catch {

DatadogSessionReplay/Tests/Processor/Builders/RecordsBuilderTests.swift

@@ -47,7 +47,7 @@ class RecordsBuilderTests: XCTestCase {
         DDAssertReflectionEqual(mutations.adds[0].wireframe, next[2])
     }
 
-    func testWhenNextWireframesAddsNewRoot_itCreatesFullSnapshotRecord() throws {
+    func testWhenNextWireframesAddsNewRoot_itCreatesIncrementalRecord() throws {
         let builder = RecordsBuilder(telemetry: TelemetryMock())
 
         // Given
@@ -58,8 +58,11 @@ class RecordsBuilderTests: XCTestCase {
         let record = builder.createIncrementalSnapshotRecord(from: .mockAny(), with: next, lastWireframes: previous)
 
         // Then
-        let fullRecord = try XCTUnwrap(record?.fullSnapshot)
-        DDAssertReflectionEqual(fullRecord.data.wireframes, next)
+        let incrementalRecord = try XCTUnwrap(record?.incrementalSnapshot)
+        guard case .mutationData = incrementalRecord.data else {
+            XCTFail("Expected `mutationData` in incremental record, got \(incrementalRecord.data)")
+            return
+        }
     }
 
     // This case does not need a full snapshot for the player to work, but adding a
@@ -68,15 +71,21 @@ class RecordsBuilderTests: XCTestCase {
         let builder = RecordsBuilder(telemetry: TelemetryMock())
 
         // Given
-        let previous: [SRWireframe] = [.mockRandomWith(id: 0), .mockRandomWith(id: 1)]
-        let next: [SRWireframe] = [.mockRandomWith(id: 1)]
+        let previous: [SRWireframe] = [
+            .shapeWireframe(value: .mockRandomWith(id: 0)),
+            .shapeWireframe(value: .mockRandomWith(id: 1))
+        ]
+        let next: [SRWireframe] = [.shapeWireframe(value: .mockRandomWith(id: 1))]
 
         // When
         let record = builder.createIncrementalSnapshotRecord(from: .mockAny(), with: next, lastWireframes: previous)
 
         // Then
-        let fullRecord = try XCTUnwrap(record?.fullSnapshot)
-        DDAssertReflectionEqual(fullRecord.data.wireframes, next)
+        let incrementalRecord = try XCTUnwrap(record?.incrementalSnapshot)
+        guard case .mutationData = incrementalRecord.data else {
+            XCTFail("Expected `mutationData` in incremental record, got \(incrementalRecord.data)")
+            return
+        }
     }
 
     func testWhenWireframesAreNotConsistent_itFallbacksToFullSnapshotRecordAndSendsErrorTelemetry() throws {

DatadogSessionReplay/Tests/Processor/SnapshotProcessorTests.swift

@@ -146,8 +146,8 @@ class SnapshotProcessorTests: XCTestCase {
         XCTAssertTrue(enrichedRecords[0].records[1].isFocusRecord)
         XCTAssertTrue(enrichedRecords[0].records[2].isFullSnapshotRecord)
 
-        XCTAssertEqual(enrichedRecords[1].records.count, 2, "It should follow with 'full snapshot' → 'incremental snapshot' records")
-        XCTAssertTrue(enrichedRecords[1].records[0].isFullSnapshotRecord)
+        XCTAssertEqual(enrichedRecords[1].records.count, 2, "It should follow with 'incremental snapshot' records")
+        XCTAssertTrue(enrichedRecords[1].records[0].isIncrementalSnapshotRecord)
         XCTAssertTrue(enrichedRecords[1].records[1].isIncrementalSnapshotRecord)
         XCTAssertEqual(enrichedRecords[1].records[1].incrementalSnapshot?.viewportResizeData?.height, 100)
         XCTAssertEqual(enrichedRecords[1].records[1].incrementalSnapshot?.viewportResizeData?.width, 200)