fix: Make scope.span writable again (#6740)

The Unreal SDK has some use cases for setting the span on the scope,
so it's also likely that some users rely on this. This PR also fixes a
force case that can lead to a crash if the set span isn't of the
internal type SentrySpan.

Fixes GH-6739

Author: philipphofmann

CHANGELOG.md

@@ -17,7 +17,6 @@
 - Removes `integrations` property from `SentryOptions` (#5749)
 - Removes `defaultIntegrations` function from `SentryOptions` (#6664)
 - Makes `SentryEventDecodable` internal (#5808)
-- The `span` property on `SentryScope` is now readonly (#5866)
 - Removes `SentryIntegrationProtocol` from the API. This is not used after the removal of the `integrations` property (#6660)
 - Removes deprecated SentryDebugImageProvider class (#5598)
 - Properties on SentryOptions that had no effect on the WithoutUIKit variant are now removed from the API (#6644)

Sources/Sentry/Public/SentryScope.h

@@ -28,7 +28,7 @@ NS_SWIFT_NAME(Scope)
  * Returns current Span or Transaction.
  * @return current Span or Transaction or null if transaction has not been set.
  */
-@property (nullable, nonatomic, readonly, strong) id<SentrySpan> span;
+@property (nullable, nonatomic, strong) id<SentrySpan> span;
 
 /**
  * The id of current session replay.

Sources/Sentry/SentryCrashIntegration.m

@@ -35,7 +35,7 @@
 void
 sentry_finishAndSaveTransaction(void)
 {
-    SentrySpan *span = (SentrySpan *)SentrySDKInternal.currentHub.scope.span;
+    SentrySpan *span = [SentrySDKInternal.currentHub.scope getCastedInternalSpan];
 
     if (span != nil) {
         SentryTracer *tracer = [span tracer];

Sources/Sentry/SentryScope.m

@@ -150,6 +150,23 @@ - (void)setPropagationContext:(SentryPropagationContext *)propagationContext
     }
 }
 
+- (nullable SentrySpan *)getCastedInternalSpan
+{
+    id<SentrySpan> span = self.span;
+
+    if (span == nil) {
+        return nil;
+    }
+
+    if (span && [span isKindOfClass:[SentrySpan class]]) {
+        return (SentrySpan *)span;
+    }
+
+    SENTRY_LOG_DEBUG(@"The span on the scope is not of type SentrySpan, returning nil.");
+
+    return nil;
+}
+
 - (void)clear
 {
     // As we need to synchronize the accesses of the arrays and dictionaries and we use the

Sources/Sentry/include/SentryScope+Private.h

@@ -5,6 +5,7 @@
 @class SentryAttachment;
 @class SentryPropagationContext;
 @class SentrySession;
+@class SentrySpan;
 
 @protocol SentryScopeObserver;
 
@@ -13,7 +14,6 @@ NS_ASSUME_NONNULL_BEGIN
 @interface SentryScope ()
 
 @property (atomic, copy, nullable) NSString *environmentString;
-@property (nullable, nonatomic, strong) id<SentrySpan> span;
 
 @property (atomic, strong, readonly) NSArray<SentryAttachment *> *attachments;
 
@@ -46,7 +46,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSArray<SentryBreadcrumb *> *)breadcrumbs;
 
-- (void)setSpan:(nullable id<SentrySpan>)span;
+- (nullable SentrySpan *)getCastedInternalSpan;
 
 /**
  * used to add values in event context.

Tests/SentryTests/SentryScopeSwiftTests.swift

@@ -798,6 +798,65 @@ class SentryScopeSwiftTests: XCTestCase {
         XCTAssertEqual(spanId.sentrySpanIdString, traceContext["span_id"] as? String)
     }
 
+    func testGetCasedInternalSpan_SpanIsNil() {
+        // -- Arrange --
+        let scope = Scope()
+
+        // -- Act --
+        let span = scope.getCastedInternalSpan()
+
+        // -- Assert --
+        XCTAssertNil(span)
+    }
+
+#if os(macOS)
+    // We test this only on macOS because the SentrySpan init methods require a frames tracker.
+    // As we're testing simple logic here, we can skip the other platforms.
+    func testGetCasedInternalSpan_SpanIsOfInternalTypeSpan() throws {
+        // -- Arrange --
+        let scope = Scope()
+        let span = SentrySpan(context: SpanContext(operation: "TEST"))
+
+        scope.span = span
+
+        // -- Act --
+        let actualSpan = try XCTUnwrap(scope.getCastedInternalSpan())
+
+        // -- Assert --
+        XCTAssertEqual(actualSpan, span)
+        XCTAssertEqual(actualSpan.spanId, span.spanId)
+    }
+
+    func testGetCasedInternalSpan_SpanIsSubClassOfInternalTypeSpan() throws {
+        // -- Arrange --
+        let scope = Scope()
+        let span = SubClassOfSentrySpan(context: SpanContext(operation: "TEST"))
+
+        scope.span = span
+
+        // -- Act --
+        let actualSpan = try XCTUnwrap(scope.getCastedInternalSpan())
+
+        // -- Assert --
+        XCTAssertEqual(actualSpan, span)
+        XCTAssertEqual(actualSpan.spanId, span.spanId)
+    }
+#endif // os(macOS)
+
+    func testGetCasedInternalSpan_SpanIsOfDifferentType() {
+        // -- Arrange --
+        let scope = Scope()
+        let span = NotOfTypeSpan()
+
+        scope.span = span
+
+        // -- Act --
+        let actualSpan = scope.getCastedInternalSpan()
+
+        // -- Assert --
+        XCTAssertNil(actualSpan)
+    }
+
     private class TestScopeObserver: NSObject, SentryScopeObserver {
         var tags: [String: String]?
         func setTags(_ tags: [String: String]?) {
@@ -863,3 +922,46 @@ class SentryScopeSwiftTests: XCTestCase {
         }
     }
 }
+
+// A minimal dummy Span implementation that is not SentrySpan.
+private final class NotOfTypeSpan: NSObject, Span {
+
+    init(traceId: SentryId = SentryId()) {
+        self.traceId = traceId
+    }
+
+    // MARK: - Properties required by Span (set to neutral values)
+    var traceId: SentryId = SentryId()
+    var spanId: SpanId = SpanId()
+    var parentSpanId: SpanId?
+    var sampled: SentrySampleDecision = .undecided
+    var operation: String = ""
+    var origin: String = ""
+    var spanDescription: String?
+    var status: SentrySpanStatus = .undefined
+    var timestamp: Date?
+    var startTimestamp: Date?
+    var data: [String: Any] { [:] }
+    var tags: [String: String] { [:] }
+    var isFinished: Bool { false }
+    var traceContext: TraceContext? { nil }
+
+    // MARK: - Methods required by Span (no-ops)
+    func startChild(operation: String) -> Span { return self }
+    func startChild(operation: String, description: String?) -> Span { return self }
+    func setData(value: Any?, key: String) {}
+    func removeData(key: String) {}
+    func setTag(value: String, key: String) {}
+    func removeTag(key: String) {}
+    func setMeasurement(name: String, value: NSNumber) {}
+    func setMeasurement(name: String, value: NSNumber, unit: MeasurementUnit) {}
+    func finish() {}
+    func finish(status: SentrySpanStatus) {}
+    func toTraceHeader() -> TraceHeader { return TraceHeader(trace: traceId, spanId: spanId, sampled: sampled) }
+    func baggageHttpHeader() -> String? { return nil }
+
+    // MARK: - SentrySerializable (no-op payload)
+    func serialize() -> [String: Any] { return [:] }
+}
+
+private final class SubClassOfSentrySpan: SentrySpan {}

sdk_api.json

@@ -14931,6 +14931,49 @@
                   "Dynamic"
                 ],
                 "accessorKind": "get"
+              },
+              {
+                "kind": "Accessor",
+                "name": "Set",
+                "printedName": "Set()",
+                "children": [
+                  {
+                    "kind": "TypeNameAlias",
+                    "name": "Void",
+                    "printedName": "Swift.Void",
+                    "children": [
+                      {
+                        "kind": "TypeNominal",
+                        "name": "Void",
+                        "printedName": "()"
+                      }
+                    ]
+                  },
+                  {
+                    "kind": "TypeNominal",
+                    "name": "Optional",
+                    "printedName": "(any Sentry.Span)?",
+                    "children": [
+                      {
+                        "kind": "TypeNominal",
+                        "name": "Span",
+                        "printedName": "any Sentry.Span",
+                        "usr": "c:objc(pl)SentrySpan"
+                      }
+                    ],
+                    "usr": "s:Sq"
+                  }
+                ],
+                "declKind": "Accessor",
+                "usr": "c:objc(cs)SentryScope(im)setSpan:",
+                "moduleName": "Sentry",
+                "isOpen": true,
+                "objc_name": "setSpan:",
+                "declAttributes": [
+                  "ObjC",
+                  "Dynamic"
+                ],
+                "accessorKind": "set"
               }
             ]
           },