test: Add tests for encodeObject with NSString (#5283)

GH-4424 reports a crash when calling dataUsingEncoding which is related
to invalid memory. This PR adds two more tests to ensure we can encode
Japanese characters and even an invalid JSONString,
which makes dataUsingEncoding return nil.

Author: philipphofmann

Tests/SentryTests/SentryCrash/SentryCrashJSONCodec_Tests.m

@@ -31,6 +31,7 @@
 #import "FileBasedTestCase.h"
 #import "SentryCrashJSONCodec.h"
 #import "SentryCrashJSONCodecObjC.h"
+#import "SentryInvalidJSONString.h"
 
 @interface SentryCrashJSONCodec_Tests : FileBasedTestCase
 @end
@@ -196,6 +197,39 @@ - (void)testSerializeDeserializeArrayString
     XCTAssertEqualObjects(result, original, @"");
 }
 
+- (void)testSerializeJapaneseArrayString
+{
+    NSError *error = (NSError *)self;
+    NSString *expected = @"[\"こんにちは\"]"; // "Hello" in Japanese
+    id original = [NSArray arrayWithObjects:@"こんにちは", nil];
+    NSString *jsonString = toString([SentryCrashJSONCodec encode:original
+                                                         options:SentryCrashJSONEncodeOptionSorted
+                                                           error:&error]);
+    XCTAssertNotNil(jsonString, @"");
+    XCTAssertNil(error, @"");
+    XCTAssertEqualObjects(jsonString, expected, @"");
+    id result = [SentryCrashJSONCodec decode:toData(jsonString) options:0 error:&error];
+    XCTAssertNotNil(result, @"");
+    XCTAssertNil(error, @"");
+    XCTAssertEqualObjects(result, original, @"");
+}
+
+- (void)testSerializeInvalidJSONString
+{
+
+    NSString *string = [[SentryInvalidJSONString alloc] initWithLengthInvocationsToBeInvalid:0];
+    NSError *error = (NSError *)self;
+
+    id original = [NSArray arrayWithObjects:string, nil];
+    NSString *jsonString = toString([SentryCrashJSONCodec encode:original
+                                                         options:SentryCrashJSONEncodeOptionSorted
+                                                           error:&error]);
+
+    XCTAssertNil(error);
+    XCTAssertEqualObjects(jsonString, @"[null]", @"");
+    XCTAssertNotNil(jsonString, @"");
+}
+
 - (void)testSerializeDeserializeArrayStringIntl
 {
     NSError *error = (NSError *)self;