[GROOVY-9890] Static type checking can't find default method overload on interface

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 3.0.7
• Fix Version/s: 3.0.8, 4.0.0-alpha-3, 2.5.16
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Robin Friedli
• Created: 10/Jan/21 02:10
• Updated: 21/Jul/22 19:30
• Resolved: 18/May/21 02:22

Description

The static type checker cannot find default methods on an interface if the method overloads an abstract method. For example, consider the following Java classes:

package net.robinfriedli.botify.scripting;

public interface TestInt {

    void foo(String s);

    default void foo(long l) {}
}

public class TestImpl implements TestInt {
    @Override
    public void foo(String s) {
    }
}

When compiling the script

new net.robinfriedli.botify.scripting.TestImpl().foo(1l)

 the following exception is thrown:

 

MultipleCompilationErrorsException:
startup failed:
Script1.groovy: 1: [Static type checking] - Cannot find matching method net.robinfriedli.botify.scripting.TestImpl#foo(long). Please check if the declared type is correct and if the method exists.
 @ line 1, column 1.
   new net.robinfriedli.botify.scripting.TestImpl().foo(1l)
   ^

1 error

The script runs fine without static compilation.

 

Calling the implemented abstract method compiles sucessfully:

new net.robinfriedli.botify.scripting.TestImpl().foo('str')

However, when changing the interface to

 

package net.robinfriedli.botify.scripting;

public interface TestInt {

    void foo(String s);

    default void bar(long l) {}
}

The following script compiles:

 

 

new net.robinfriedli.botify.scripting.TestImpl().bar(1l)

 

The scripts are executed in Java by GroovyShell#evaluate using the following compiler configuration:

CompilerConfiguration compilerConfiguration = new CompilerConfiguration();
ASTTransformationCustomizer compileStaticCustomizer = new ASTTransformationCustomizer(
    singletonMap("extensions", singletonList("net.robinfriedli.botify.scripting.TypeCheckingExtension")),
    CompileStatic.class
);

compilerConfiguration.addCompilationCustomizers(compileStaticCustomizer);
return compilerConfiguration;

 

Issue Links

• relates to: GROOVY-10700 STC cannot locate method specified by interface but supplied by AST transform