feat: support construct simple interface and abstract class

testable-core/src/main/java/com/alibaba/testable/core/util/ConstructionUtil.java

@@ -1,8 +1,11 @@
 package com.alibaba.testable.core.util;
 
 import com.alibaba.testable.core.compile.InMemoryJavaCompiler;
+import com.alibaba.testable.core.tool.OmniConstructor;
 
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.lang.reflect.Parameter;
 
 import static com.alibaba.testable.core.constant.ConstPool.DOLLAR;
 import static com.alibaba.testable.core.constant.ConstPool.DOT;
@@ -19,7 +22,23 @@ public class ConstructionUtil {
                 .append(clazz.getName().replace(DOLLAR, DOT))
                 .append(" {\n");
         for (Method m : clazz.getMethods()) {
-
+            if (!Modifier.isStatic(m.getModifiers()) && !Modifier.isFinal(m.getModifiers())) {
+                sourceCode.append("\tpublic ").append(m.getReturnType().getName().replace(DOLLAR, DOT)).append(" ")
+                        .append(m.getName()).append("(");
+                Class<?>[] parameters = m.getParameterTypes();
+                for (int i = 0; i < parameters.length; i++) {
+                    sourceCode.append(getParameterName(parameters[i])).append(" p").append(i);
+                    if (i < parameters.length - 1) {
+                        sourceCode.append(", ");
+                    }
+                }
+                sourceCode.append(") {\n");
+                if (!m.getReturnType().equals(void.class)) {
+                    sourceCode.append("\t\treturn ").append(OmniConstructor.class.getName().replace(DOLLAR, DOT)).append(".")
+                            .append("newInstance(").append(m.getReturnType().getName().replace(DOLLAR, DOT)).append(".class);\n");
+                }
+                sourceCode.append("\t}\n");
+            }
         }
         sourceCode.append("}");
 
@@ -33,6 +52,13 @@ public class ConstructionUtil {
         }
     }
 
+    private static String getParameterName(Class<?> parameter) {
+        if (parameter.isArray()) {
+            return getParameterName(parameter.getComponentType()) + "[]";
+        }
+        return parameter.getName().replace(DOLLAR, DOT);
+    }
+
     private static String getSubclassName(Class<?> clazz) {
         return clazz.getSimpleName() + TESTABLE_IMPL;
     }

testable-core/src/test/java/com/alibaba/testable/core/util/ConstructionUtilTest.java

@@ -0,0 +1,41 @@
+package com.alibaba.testable.core.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ConstructionUtilTest {
+
+    public interface EmptyInterface {}
+
+    public interface RealInterface {
+        void fun1();
+        int func2(double d, boolean b);
+        String fun3(String s, byte[] b);
+        EmptyInterface fun4(RealInterface i);
+    }
+
+    public static abstract class AbstractClazz implements RealInterface {
+        @Override
+        public void fun1() {}
+        public static <T> T useless() { return null; }
+    }
+
+    @Test
+    void should_generate_empty_interface() throws Exception {
+        EmptyInterface ins = ConstructionUtil.generateSubClassOf(EmptyInterface.class);
+        assertNotNull(ins);
+    }
+
+    @Test
+    void should_generate_real_interface() throws Exception {
+        RealInterface ins = ConstructionUtil.generateSubClassOf(RealInterface.class);
+        assertNotNull(ins);
+    }
+
+    @Test
+    void should_generate_abstract_class() throws Exception {
+        RealInterface ins = ConstructionUtil.generateSubClassOf(AbstractClazz.class);
+        assertNotNull(ins);
+    }
+}