Don't generate visibility bridge for package private default implementations

Author: sgerke-1L

modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/transformation/InliningClassTransformer.kt

@@ -15,6 +15,7 @@ import net.bytebuddy.asm.AsmVisitorWrapper
 import net.bytebuddy.description.ModifierReviewable.OfByteCodeElement
 import net.bytebuddy.description.method.MethodDescription
 import net.bytebuddy.dynamic.ClassFileLocator.Simple.of
+import net.bytebuddy.dynamic.VisibilityBridgeStrategy
 import net.bytebuddy.matcher.ElementMatchers.*
 import java.io.File
 import java.lang.instrument.ClassFileTransformer
@@ -71,7 +72,9 @@ internal class InliningClassTransformer(
                 ?: return classfileBuffer
 
         try {
-            val builder = byteBuddy.redefine(classBeingRedefined, of(classBeingRedefined.name, classfileBuffer))
+            val builder = byteBuddy
+                .with(VisibilityBridgeStrategy { not(isDefaultMethod()).matches(it) })
+                .redefine(classBeingRedefined, of(classBeingRedefined.name, classfileBuffer))
                 .visit(FixParameterNamesVisitor(classBeingRedefined))
 
             val type = builder

modules/mockk-agent/src/jvmTest/java/io/mockk/proxy/JvmMockKProxyMakerTest.java

@@ -411,6 +411,25 @@ public void openClassAnnotationProxy() throws Exception {
         checkProxyHandlerCalled(1, proxy, "i", 1, 1);
     }
 
+    interface InterfaceWithDefault {
+        default void foo(Runnable d) {
+            d.run();
+        }
+    }
+
+    static public class ClassImplementingPackagePrivateInterfaceWithDefaultMethod implements InterfaceWithDefault {
+    }
+
+    @Test
+    public void classImplementingPackagePrivateInterfaceWithDefaultMethodProxy() {
+        ClassImplementingPackagePrivateInterfaceWithDefaultMethod proxy = makeProxy(ClassImplementingPackagePrivateInterfaceWithDefaultMethod.class);
+
+        proxy.foo(() -> { executed[0] = true; });
+
+        assertFalse(executed[0]);
+        checkProxyHandlerCalled(1, proxy, "foo", 1, 1);
+    }
+
     private void checkProxyHandlerCalled(int nTimes, Object proxy, String methodName) {
         checkProxyHandlerCalled(nTimes, proxy, methodName, 0, 0);
     }

test-modules/client-tests/src/jvmTest/java/io/mockk/core/ClassImplementingInterfaceWithDefaultMethod.java

@@ -0,0 +1,11 @@
+package io.mockk.core;
+
+
+interface InterfaceWithDefault {
+    default int foo() {
+        return 10;
+    }
+}
+
+public class ClassImplementingPackagePrivateInterfaceWithDefaultMethod implements InterfaceWithDefault {
+}

test-modules/client-tests/src/jvmTest/java/io/mockk/core/ClassImplementingPackagePrivateInterfaceWithDefaultMethod.java

@@ -1,6 +1,6 @@
 package io.mockk.impl
 
-import io.mockk.core.ClassImplementingInterfaceWithDefaultMethod
+import io.mockk.core.ClassImplementingPackagePrivateInterfaceWithDefaultMethod
 import io.mockk.every
 import io.mockk.mockk
 import org.junit.jupiter.api.Assertions.assertEquals
@@ -9,9 +9,9 @@ import org.junit.jupiter.api.Test
 
 class DefaultMethodTest {
     @Test
-    fun `should mock ClassImplementingInterfaceWithDefaultMethod class`() {
-        val tableImpl = mockk<ClassImplementingInterfaceWithDefaultMethod>()
-        every { tableImpl.foo() } returns 12
-        assertEquals(12, tableImpl.toString())
+    fun `should mock ClassImplementingPackagePrivateInterfaceWithDefaultMethod class`() {
+        val obj = mockk<ClassImplementingPackagePrivateInterfaceWithDefaultMethod>()
+        every { obj.foo() } returns 12
+        assertEquals(12, obj.foo())
     }
 }