Some tests for override action has been added.

idea/testData/codeInsight/overrideImplement/complexMultiOverride.kt

@@ -0,0 +1,9 @@
+open class Base<A, B, C>() {
+    open val method : (A?) -> A = { it!! }
+    open fun foo(value : B) : B = value
+    open fun bar(value : () -> C) : (String) -> C = { value() }
+}
+
+class C : Base<String, C, Unit>() {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/complexMultiOverride.kt.after

@@ -0,0 +1,16 @@
+open class Base<A, B, C>() {
+    open val method : (A?) -> A = { it!! }
+    open fun foo(value : B) : B = value
+    open fun bar(value : () -> C) : (String) -> C = { value() }
+}
+
+class C : Base<String, C, Unit>() {
+
+    override fun bar(value : () -> Unit) : (String) -> Unit {
+        return super<Base>.bar(value)
+    }
+    override fun foo(value : C) : C {
+        return super<Base>.foo(value)
+    }
+    override val method : (String?) -> String = ?
+}

idea/testData/codeInsight/overrideImplement/functionProperty.kt

@@ -4,5 +4,5 @@ trait A {
 }
 
 fun some() : A {
-    return object A {<caret>}
+    return object : A {<caret>}
 }

idea/testData/codeInsight/overrideImplement/functionProperty.kt.after

@@ -4,7 +4,7 @@ trait A {
 }
 
 fun some() : A {
-    return object A {
+    return object : A {
         override val method : () -> Unit? = ?
     }
 }

idea/testData/codeInsight/overrideImplement/multiOverride.kt

@@ -0,0 +1,8 @@
+trait A {
+    fun foo(value : String) : Int = 0
+    fun bar() : String = "hello"
+}
+
+class C : A {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/multiOverride.kt.after

@@ -0,0 +1,14 @@
+trait A {
+    fun foo(value : String) : Int = 0
+    fun bar() : String = "hello"
+}
+
+class C : A {
+
+    override fun bar() : String {
+        return super<A>.bar()
+    }
+    override fun foo(value : String) : Int {
+        return super<A>.foo(value)
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideFunctionProperty.kt

@@ -0,0 +1,7 @@
+open class A() {
+    open val method : () -> Unit? = {println("hello")}
+}
+
+fun some() : A {
+    return object : A() {<caret>}
+}

idea/testData/codeInsight/overrideImplement/overrideFunctionProperty.kt.after

@@ -0,0 +1,9 @@
+open class A() {
+    open val method : () -> Unit? = {println("hello")}
+}
+
+fun some() : A {
+    return object : A() {
+        override val method : () -> Unit? = ?
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideGenericFunction.kt

@@ -0,0 +1,7 @@
+trait A<T> {
+    fun foo(value : T) : Unit = println(value)
+}
+
+class C : A<C> {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/overrideGenericFunction.kt.after

@@ -0,0 +1,10 @@
+trait A<T> {
+    fun foo(value : T) : Unit = println(value)
+}
+
+class C : A<C> {
+
+    override fun foo(value : C) {
+        super<A>.foo(value)
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideJavaMethod/foo/A.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package foo;
+
+class A {
+    int getAnswer(String[] array, int number, Object value) {
+        return 42;
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideJavaMethod/foo/Impl.kt

@@ -0,0 +1,5 @@
+import foo.A
+
+class C : A() {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/overrideJavaMethod/foo/Impl.kt.after

@@ -0,0 +1,8 @@
+import foo.A
+
+class C : A() {
+
+    override fun getAnswer(array : Array<String?>?, number : Int, value : Any?) : Int {
+        return super<A>.getAnswer(array, number, value)
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideNonUnitFunction.kt

@@ -0,0 +1,7 @@
+trait A {
+    fun foo(value : String) : Int = 0
+}
+
+class C : A {
+  <caret>
+}

idea/testData/codeInsight/overrideImplement/overrideNonUnitFunction.kt.after

@@ -0,0 +1,10 @@
+trait A {
+    fun foo(value : String) : Int = 0
+}
+
+class C : A {
+
+    override fun foo(value : String) : Int {
+        return super<A>.foo(value)
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideRespectCaretPosition.kt

@@ -0,0 +1,16 @@
+open class A() {
+    open fun foo(value : Int) : Unit = println(value)
+    open val bar : Int = 0
+}
+
+class C : A() {
+    val constant = 42
+    // Some comment
+    <caret>
+    /*
+        Some another comment
+    */
+    fun someAnotherFunction() {
+
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideRespectCaretPosition.kt.after

@@ -0,0 +1,20 @@
+open class A() {
+    open fun foo(value : Int) : Unit = println(value)
+    open val bar : Int = 0
+}
+
+class C : A() {
+    val constant = 42
+    // Some comment
+    override val bar : Int = 0
+    override fun foo(value : Int) {
+        super<A>.foo(value)
+    }
+
+    /*
+        Some another comment
+    */
+    fun someAnotherFunction() {
+
+    }
+}

idea/testData/codeInsight/overrideImplement/overrideUnitFunction.kt

@@ -0,0 +1,7 @@
+trait A {
+    fun foo(value : String) : Unit = 0
+}
+
+class C : A {
+  <caret>
+}

idea/testData/codeInsight/overrideImplement/overrideUnitFunction.kt.after

@@ -0,0 +1,10 @@
+trait A {
+    fun foo(value : String) : Unit = 0
+}
+
+class C : A {
+
+    override fun foo(value : String) {
+        super<A>.foo(value)
+    }
+}

idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java

@@ -35,6 +35,7 @@ import java.util.Set;
 
 /**
  * @author yole
+ * @author slukjanov aka Frostman
  */
 public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
     @NotNull
@@ -50,69 +51,125 @@ public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
     }
 
     public void testFunctionMethod() {
-        doFileTest();
+        doImplementFileTest();
     }
 
     public void testFunctionProperty() {
-        doFileTest();
+        doImplementFileTest();
     }
 
     public void testJavaInterfaceMethod() {
-        doDirectoryTest();
+        doImplementDirectoryTest();
     }
 
     public void testJavaParameters() {
-        doDirectoryTest();
+        doImplementDirectoryTest();
     }
     
     public void testGenericMethod() {
-        doFileTest();
+        doImplementFileTest();
     }
 
     public void testProperty() {
-        doFileTest();
+        doImplementFileTest();
     }
 
-    public void testTraitGenericOverride() {
+    public void testTraitGenericImplement() {
-        doFileTest();
+        doImplementFileTest();
     }
 
     public void testRespectCaretPosition() {
-        doMultiFileTest();
+        doMultiImplementFileTest();
     }
 
     public void testGenerateMulti() {
-        doMultiFileTest();
+        doMultiImplementFileTest();
     }
 
     public void testTraitNullableFunction() {
-        doFileTest();
+        doImplementFileTest();
     }
 
-    private void doFileTest() {
+    public void testOverrideUnitFunction() {
+        doOverrideFileTest();
+    }
+
+    public void testOverrideNonUnitFunction() {
+        doOverrideFileTest();
+    }
+
+    public void testOverrideFunctionProperty() {
+        doOverrideFileTest();
+    }
+
+    public void testOverrideGenericFunction() {
+        doOverrideFileTest();
+    }
+
+    public void testMultiOverride() {
+        doMultiOverrideFileTest();
+    }
+
+    public void testComplexMultiOverride() {
+        doMultiOverrideFileTest();
+    }
+
+    public void testOverrideRespectCaretPosition() {
+        doMultiOverrideFileTest();
+    }
+
+    public void testOverrideJavaMethod() {
+        doOverrideDirectoryTest();
+    }
+
+    private void doImplementFileTest() {
+        doFileTest(new ImplementMethodsHandler());
+    }
+
+    private void doOverrideFileTest() {
+        doFileTest(new OverrideMethodsHandler());
+    }
+
+    private void doMultiImplementFileTest() {
+        doMultiFileTest(new ImplementMethodsHandler());
+    }
+
+    private void doMultiOverrideFileTest() {
+        doMultiFileTest(new OverrideMethodsHandler());
+    }
+
+    private void doImplementDirectoryTest() {
+        doDirectoryTest(new ImplementMethodsHandler());
+    }
+
+    private void doOverrideDirectoryTest() {
+        doDirectoryTest(new OverrideMethodsHandler());
+    }
+
+    private void doFileTest(OverrideImplementMethodsHandler handler) {
         myFixture.configureByFile(getTestName(true) + ".kt");
-        doImplement();
+        doOverrideImplement(handler);
         myFixture.checkResultByFile(getTestName(true) + ".kt.after");
     }
 
-    private void doMultiFileTest() {
+    private void doMultiFileTest(OverrideImplementMethodsHandler handler) {
         myFixture.configureByFile(getTestName(true) + ".kt");
-        doMultiImplement();
+        doMultiOverrideImplement(handler);
         myFixture.checkResultByFile(getTestName(true) + ".kt.after");
     }
 
-    private void doDirectoryTest() {
+    private void doDirectoryTest(OverrideImplementMethodsHandler handler) {
         myFixture.copyDirectoryToProject(getTestName(true), "");
         myFixture.configureFromTempProjectFile("foo/Impl.kt");
-        doImplement();
+        doOverrideImplement(handler);
         myFixture.checkResultByFile(getTestName(true) + "/foo/Impl.kt.after");
     }
 
-    private void doImplement() {
+    private void doOverrideImplement(OverrideImplementMethodsHandler handler) {
         final PsiElement elementAtCaret = myFixture.getFile().findElementAt(myFixture.getEditor().getCaretModel().getOffset());
         final JetClassOrObject classOrObject = PsiTreeUtil.getParentOfType(elementAtCaret, JetClassOrObject.class);
         assertNotNull("Caret should be inside class or object", classOrObject);
-        final Set<CallableMemberDescriptor> descriptors = new ImplementMethodsHandler().collectMethodsToGenerate(classOrObject);
+        final Set<CallableMemberDescriptor> descriptors = handler.collectMethodsToGenerate(classOrObject);
         assertEquals("Invalid number of available descriptors for override", 1, descriptors.size());
         new WriteCommandAction(myFixture.getProject(), myFixture.getFile()) {
             @Override
@@ -124,11 +181,11 @@ public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
         }.execute();
     }
 
-    private void doMultiImplement() {
+    private void doMultiOverrideImplement(OverrideImplementMethodsHandler handler) {
         final PsiElement elementAtCaret = myFixture.getFile().findElementAt(myFixture.getEditor().getCaretModel().getOffset());
         final JetClassOrObject classOrObject = PsiTreeUtil.getParentOfType(elementAtCaret, JetClassOrObject.class);
         assertNotNull("Caret should be inside class or object", classOrObject);
-        final Set<CallableMemberDescriptor> descriptors = new ImplementMethodsHandler().collectMethodsToGenerate(classOrObject);
+        final Set<CallableMemberDescriptor> descriptors = handler.collectMethodsToGenerate(classOrObject);
 
         final ArrayList<CallableMemberDescriptor> descriptorsList = new ArrayList<CallableMemberDescriptor>(descriptors);
         Collections.sort(descriptorsList, new Comparator<CallableMemberDescriptor>() {