Test: Unquoted property at start
Got:      {"source":"1","markerLastID":3}
Status:   ✅ PASSED

Test: Multiple properties
Got:      {"source":"/path/file.svg","width":100}
Status:   ✅ PASSED

Test: Single quotes
Got:      {"source":"/path/file.svg"}
Status:   ✅ PASSED

Summary: 3/3 tests passed