[GROOVY-8445] Static analysis does not work properly when coercing Closure to FunctionInterface

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha-1, 2.5.0-beta-2, 2.4.13, 2.6.0-alpha-2
• Fix Version/s: 2.5.0-beta-3, 2.6.0-alpha-3, 2.4.14, 3.0.0-alpha-2
• Component/s: Static Type Checker
• Assignee: Daniel Sun
• Reporter: Daniel Sun
• Created: 12/Jan/18 15:10
• Updated: 02/Feb/18 10:08
• Resolved: 02/Feb/18 10:08

Description

The following code fails when executing in static compilation mode.

        import groovy.transform.CompileStatic
        import java.util.stream.Collectors
        import java.util.stream.Stream
        
        @CompileStatic     // if we comment this line, the code works in dynamic mode.
        public class Test1 {
            public static void main(String[] args) {
                p();
            }
            
            public static void p() {
                assert 13 == Stream.of(1, 2, 3).reduce(7, {r, e -> r + e});
            }
        }

Here is the error message:

[Static type checking] - Cannot find matching method java.util.stream.Stream#reduce(int, groovy.lang.Closure). Please check if the declared type is correct and if the method exists.
 at line: 12, column: 30

[Static type checking] - Cannot find matching method java.lang.Object#plus(java.lang.Object). Please check if the declared type is correct and if the method exists.
 at line: 12, column: 68

Similarly, the following code fails in static compilation mode too:

        import groovy.transform.CompileStatic
        import java.util.stream.Collectors
        import java.util.stream.Stream
        
        @CompileStatic  // if we comment this line, the code works in dynamic mode.
        public class Test1 {
            public static void main(String[] args) {
                p();
            }
            
            public static void p() {
                def list = [1, 2, 3]
                list.replaceAll { e -> e + 10 }
                assert [11, 12, 13] == list
            }
        }

Here is the error message:

[Static type checking] - Cannot find matching method java.util.List#replaceAll(groovy.lang.Closure). Please check if the declared type is correct and if the method exists.
 at line: 13, column: 17

[Static type checking] - Cannot find matching method java.lang.Object#plus(int). Please check if the declared type is correct and if the method exists.
 at line: 13, column: 40