diff --git a/compiler/testData/diagnostics/tests/Override.jet b/compiler/testData/diagnostics/tests/Override.jet
deleted file mode 100644
index d7d6997e0cd..00000000000
--- a/compiler/testData/diagnostics/tests/Override.jet
+++ /dev/null
@@ -1,112 +0,0 @@
-// FILE: f.kt
-package override.normal
-    trait MyTrait {
-        fun foo()
-        val pr : Unit
-    }
-
-    abstract class MyAbstractClass {
-        abstract fun bar()
-        abstract val prr : Unit
-
-    }
-
-    open class MyClass() : MyTrait, MyAbstractClass() {
-        override fun foo() {}
-        override fun bar() {}
-
-        override val pr : Unit = #()
-        override val prr : Unit = #()
-    }
-
-    class MyChildClass() : MyClass() {}
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass<!> : MyTrait, MyAbstractClass() {}
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass2<!>() : MyTrait, MyAbstractClass() {
-        override fun foo() {}
-        override val pr : Unit = #()
-        override val prr : Unit = #()
-    }
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass3<!>() : MyTrait, MyAbstractClass() {
-        override fun bar() {}
-        override val pr : Unit = #()
-        override val prr : Unit = #()
-    }
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass4<!>() : MyTrait, MyAbstractClass() {
-        fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>() {}
-        val <!VIRTUAL_MEMBER_HIDDEN, MUST_BE_INITIALIZED_OR_BE_ABSTRACT!>pr<!> : Unit
-        <!NOTHING_TO_OVERRIDE!>override<!> fun other() {}
-        <!NOTHING_TO_OVERRIDE!>override<!> val otherPr : Int = 1
-    }
-
-    class MyChildClass1() : MyClass() {
-        fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>() {}
-        val <!VIRTUAL_MEMBER_HIDDEN!>pr<!> : Unit = #()
-        override fun bar() {}
-        override val prr : Unit = #()
-    }
-
-// FILE: f.kt
-
-package override.generics
-    trait MyTrait<T> {
-        fun foo(t: T) : T
-    }
-
-    abstract class MyAbstractClass<T> {
-        abstract fun bar(t: T) : T
-        abstract val pr : T
-    }
-
-    trait MyProps<T> {
-        val p : T
-    }
-
-    open class MyGenericClass<T>(t : T) : MyTrait<T>, MyAbstractClass<T>(), MyProps<T> {
-        override fun foo(t: T) = t
-        override fun bar(t: T) = t
-        override val p : T = t
-        override val pr : T = t
-    }
-
-    class MyChildClass() : MyGenericClass<Int>(1) {}
-    class MyChildClass1<T>(t : T) : MyGenericClass<T>(t) {}
-    class MyChildClass2<T>(t : T) : MyGenericClass<T>(t) {
-        fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>(t: T) = t
-        val <!VIRTUAL_MEMBER_HIDDEN!>pr<!> : T = t
-        override fun bar(t: T) = t
-        override val p : T = t
-    }
-
-    open class MyClass() : MyTrait<Int>, MyAbstractClass<String>() {
-        override fun foo(i: Int) = i
-        override fun bar(s: String) = s
-        override val pr : String = "1"
-    }
-
-    abstract class MyAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {
-        override fun foo(i: Int) = i
-        override fun bar(s: String) = s
-    }
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
-        <!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R) = r
-        <!NOTHING_TO_OVERRIDE!>override<!> val <T> pr : R = r
-    }
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}
-    abstract class MyLegalAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {}
-
-    class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass2<!><T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
-        fun foo(t: T) = t
-        fun bar(t: T) = t
-        val <R> pr : T = t
-    }
-    abstract class MyLegalAbstractClass2<T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
-        fun foo(t: T) = t
-        fun bar(t: T) = t
-        val <R> pr : T = t
-    }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/override/AbstractFunImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractFunImplemented.jet
new file mode 100644
index 00000000000..ef6b6fa41b8
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractFunImplemented.jet
@@ -0,0 +1,7 @@
+abstract class A {
+    abstract fun foo(): Int
+}
+
+class B() : A() {
+    override fun foo() = 1
+}
diff --git a/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.jet
new file mode 100644
index 00000000000..828620f7fbf
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.jet
@@ -0,0 +1,6 @@
+abstract class A {
+    abstract fun foo(): Int
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>B<!>() : A() {
+}
diff --git a/compiler/testData/diagnostics/tests/override/AbstractValImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractValImplemented.jet
new file mode 100644
index 00000000000..a9669a69142
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractValImplemented.jet
@@ -0,0 +1,7 @@
+abstract class A {
+    abstract val i: Int
+}
+
+class B() : A() {
+    override val i = 1
+}
diff --git a/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.jet
new file mode 100644
index 00000000000..8fcad310a23
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.jet
@@ -0,0 +1,6 @@
+abstract class A {
+    abstract val i: Int
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>B<!>() : A() {
+}
diff --git a/compiler/testData/diagnostics/tests/override/AbstractVarImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractVarImplemented.jet
new file mode 100644
index 00000000000..b0c3055b5fa
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractVarImplemented.jet
@@ -0,0 +1,7 @@
+abstract class A {
+    abstract var i: Int
+}
+
+class B() : A() {
+    override var i = 1
+}
diff --git a/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.jet b/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.jet
new file mode 100644
index 00000000000..b843856edce
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.jet
@@ -0,0 +1,6 @@
+abstract class A {
+    abstract var i: Int
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>B<!>() : A() {
+}
diff --git a/compiler/testData/diagnostics/tests/override/DelegationFun.jet b/compiler/testData/diagnostics/tests/override/DelegationFun.jet
new file mode 100644
index 00000000000..e2236b35b97
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/DelegationFun.jet
@@ -0,0 +1,7 @@
+package delegation
+
+trait Aaa {
+    fun foo()
+}
+
+class Bbb(aaa: Aaa) : Aaa by aaa
diff --git a/compiler/testData/diagnostics/tests/override/DelegationVal.jet b/compiler/testData/diagnostics/tests/override/DelegationVal.jet
new file mode 100644
index 00000000000..076e5775265
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/DelegationVal.jet
@@ -0,0 +1,7 @@
+package delegation
+
+trait Aaa {
+    val i: Int
+}
+
+class Bbb(aaa: Aaa) : Aaa by aaa
diff --git a/compiler/testData/diagnostics/tests/override/DelegationVar.jet b/compiler/testData/diagnostics/tests/override/DelegationVar.jet
new file mode 100644
index 00000000000..5b8b34d62be
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/DelegationVar.jet
@@ -0,0 +1,7 @@
+package delegation
+
+trait Aaa {
+    var i: Int
+}
+
+class Bbb(aaa: Aaa) : Aaa by aaa
diff --git a/compiler/testData/diagnostics/tests/override/Generics.jet b/compiler/testData/diagnostics/tests/override/Generics.jet
new file mode 100644
index 00000000000..2e46a163bd0
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/Generics.jet
@@ -0,0 +1,60 @@
+package override.generics
+
+trait MyTrait<T> {
+    fun foo(t: T) : T
+}
+
+abstract class MyAbstractClass<T> {
+    abstract fun bar(t: T) : T
+    abstract val pr : T
+}
+
+trait MyProps<T> {
+    val p : T
+}
+
+open class MyGenericClass<T>(t : T) : MyTrait<T>, MyAbstractClass<T>(), MyProps<T> {
+    override fun foo(t: T) = t
+    override fun bar(t: T) = t
+    override val p : T = t
+    override val pr : T = t
+}
+
+class MyChildClass() : MyGenericClass<Int>(1) {}
+class MyChildClass1<T>(t : T) : MyGenericClass<T>(t) {}
+class MyChildClass2<T>(t : T) : MyGenericClass<T>(t) {
+    fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>(t: T) = t
+    val <!VIRTUAL_MEMBER_HIDDEN!>pr<!> : T = t
+    override fun bar(t: T) = t
+    override val p : T = t
+}
+
+open class MyClass() : MyTrait<Int>, MyAbstractClass<String>() {
+    override fun foo(i: Int) = i
+    override fun bar(s: String) = s
+    override val pr : String = "1"
+}
+
+abstract class MyAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {
+    override fun foo(i: Int) = i
+    override fun bar(s: String) = s
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
+    <!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R) = r
+    <!NOTHING_TO_OVERRIDE!>override<!> val <T> pr : R = r
+}
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}
+abstract class MyLegalAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass2<!><T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
+    fun foo(t: T) = t
+    fun bar(t: T) = t
+    val <R> pr : T = t
+}
+abstract class MyLegalAbstractClass2<T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
+    fun foo(t: T) = t
+    fun bar(t: T) = t
+    val <R> pr : T = t
+}
diff --git a/compiler/testData/diagnostics/tests/override/NonGenerics.jet b/compiler/testData/diagnostics/tests/override/NonGenerics.jet
new file mode 100644
index 00000000000..59d099ed572
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/override/NonGenerics.jet
@@ -0,0 +1,50 @@
+package override.normal
+
+trait MyTrait {
+    fun foo()
+    val pr : Unit
+}
+
+abstract class MyAbstractClass {
+    abstract fun bar()
+    abstract val prr : Unit
+
+}
+
+open class MyClass() : MyTrait, MyAbstractClass() {
+    override fun foo() {}
+    override fun bar() {}
+
+    override val pr : Unit = #()
+    override val prr : Unit = #()
+}
+
+class MyChildClass() : MyClass() {}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass<!> : MyTrait, MyAbstractClass() {}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass2<!>() : MyTrait, MyAbstractClass() {
+    override fun foo() {}
+    override val pr : Unit = #()
+    override val prr : Unit = #()
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass3<!>() : MyTrait, MyAbstractClass() {
+    override fun bar() {}
+    override val pr : Unit = #()
+    override val prr : Unit = #()
+}
+
+class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass4<!>() : MyTrait, MyAbstractClass() {
+    fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>() {}
+    val <!VIRTUAL_MEMBER_HIDDEN, MUST_BE_INITIALIZED_OR_BE_ABSTRACT!>pr<!> : Unit
+    <!NOTHING_TO_OVERRIDE!>override<!> fun other() {}
+    <!NOTHING_TO_OVERRIDE!>override<!> val otherPr : Int = 1
+}
+
+class MyChildClass1() : MyClass() {
+    fun <!VIRTUAL_MEMBER_HIDDEN!>foo<!>() {}
+    val <!VIRTUAL_MEMBER_HIDDEN!>pr<!> : Unit = #()
+    override fun bar() {}
+    override val prr : Unit = #()
+}