UnusedMethodParameter.md

Pattern: Unused method parameter

Issue: -

Description

This rule finds instances of method parameters not being used. It does not analyze private methods or methods marked @Override.

• This rule ignores main() methods. In Groovy, the main()>> method can either specify a <<<void return type or else omit a return type (be dynamically typed). The main()>> method must have exactly one parameter. That parameter can either be typed as <<<String[] or else the type can be omitted (be dynamically typed). And the main()>> method must be <<<static.
• You can specify an ignore list of parameter names using the ignoreRegex property. By default, a parameter named ignore or ignored does not trigger a violation (the regex value is ignore|ignored). You can add your own ignore list using this property.
• You can specify a class name pattern to ignore using the ignoreClassRegex property. By default classes named \*.Category are ignored because they are category classes and have unused parameters in static methods.

Example of violations:

    class SomeClass {
        def method(def param) {
            // param is unused
        }
    }

Example of code that does not cause violations:

    class SomeClass {
        @Override
        def otherMethod(def param) {
            // this is OK because it overrides a super class
        }
    }

    class SomeCategory {
        // Category classes are ignored by default
        void someMethod1(String string, int value) { }
        void someMethod1(String string, int value, name) { }
    }

    class MainClass1 {
        // main() methods are ignored
        public static void main(String[] args) { }
    }
    class MainClass2 {
        // This is also a valid Groovy main() method
        static main(args) { }
    }

Further Reading

• CodeNarc - UnusedMethodParameter