Why you should care
Because force casting (as!) does not perform any type safety validations, it is capable of performing dangerous conversions between unrelated types. When the types are truly unrelated, the cast will cause a system crash.
How we detect
CAST Highlight counts one occurrence each time a “as!” pattern is detected in source code.
Bad Code
foo as! MyClass // Noncompliant
Good Code
foo as? MyClass
References
CppCoreGuidelines, Type safety profile – Type.1: Don’t use reinterpret_cast
https://rules.sonarsource.com/swift/RSPEC-3630
https://rules.sonarsource.com/swift/RSPEC-3630
About CAST and Highlight’s Code Insights
Over the last 25 years, CAST has leveraged unique knowledge on software quality measurement by analyzing thousands of applications and billions of lines of code. Based on this experience and community standards on programming best practices, Highlight implements hundreds of code insights across 15+ technologies to calculate health factors of a software.