feat: Add synthetic for mechanism (#2501)

Add synthetic property for SentryMechanism.

CHANGELOG.md

@@ -8,6 +8,7 @@ This version adds a dependency on Swift.
 
 - Properly demangle Swift class name (#2162)
 - Enable File I/O APM by default (#2497)
+- Add synthetic for mechanism (#2501)
 
 ### Fixes
 

Sources/Sentry/Public/SentryMechanism.h

@@ -35,6 +35,12 @@ SENTRY_NO_INIT
  */
 @property (nonatomic, copy) NSNumber *_Nullable handled;
 
+/**
+ * An optional flag indicating a synthetic exception. For more info visit
+ * https://develop.sentry.dev/sdk/event-payloads/exception/#exception-mechanism.
+ */
+@property (nonatomic, copy, nullable) NSNumber *synthetic;
+
 /**
  * Fully qualified URL to an online help resource, possible
  * interpolated with error parameters

Sources/Sentry/SentryMechanism.m

@@ -21,6 +21,7 @@ - (instancetype)initWithType:(NSString *)type
     NSMutableDictionary *serializedData = @{ @"type" : self.type }.mutableCopy;
 
     [serializedData setValue:self.handled forKey:@"handled"];
+    [serializedData setValue:self.synthetic forKey:@"synthetic"];
     [serializedData setValue:self.desc forKey:@"description"];
     [serializedData setValue:[self.data sentry_sanitize] forKey:@"data"];
     [serializedData setValue:self.helpLink forKey:@"help_link"];

Tests/SentryTests/Protocol/SentryMechanismTests.swift

@@ -15,6 +15,7 @@ class SentryMechanismTests: XCTestCase {
         XCTAssertEqual(expected.type, actual["type"] as! String)
         XCTAssertEqual(expected.desc, actual["description"] as? String)
         XCTAssertEqual(expected.handled, actual["handled"] as? NSNumber)
+        XCTAssertEqual(expected.synthetic, actual["synthetic"] as? NSNumber)
         XCTAssertEqual(expected.helpLink, actual["help_link"] as? String)
 
         guard let something = (actual["data"] as? [String: Any])?["something"] as? [String: Any] else {
@@ -28,4 +29,13 @@ class SentryMechanismTests: XCTestCase {
 
         XCTAssertNotNil(actual["meta"])
     }
+
+    func testSerialize_OnlyType_NullablePropertiesNotAdded() {
+        let type = "type"
+        let mechanism = Mechanism(type: type)
+
+        let actual = mechanism.serialize()
+        XCTAssertEqual(1, actual.count)
+        XCTAssertEqual(type, actual["type"] as? String)
+    }
 }

Tests/SentryTests/Protocol/TestData.swift

@@ -94,6 +94,7 @@ class TestData {
         mechanism.data = ["something": ["date": currentDateProvider.date()]]
         mechanism.desc = "desc"
         mechanism.handled = true
+        mechanism.synthetic = false
         mechanism.helpLink = "https://www.sentry.io"
         mechanism.meta = mechanismMeta