"as" in binary / unary expressions now checked only for original type conversion #KT-10384 Fixed

Also #KT-10386 Fixed

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java

@@ -349,6 +349,11 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             KtExpression receiver = ((KtQualifiedExpression) parent).getReceiverExpression();
             return PsiTreeUtil.isAncestor(receiver, expression, false);
         }
+        // in binary expression, left argument can be a receiver and right an argument
+        // in unary expression, left argument can be a receiver
+        if (parent instanceof KtBinaryExpression || parent instanceof KtUnaryExpression) {
+            return true;
+        }
         return false;
     }
 

compiler/testData/diagnostics/tests/cast/AsInBinaryUnary.kt

@@ -0,0 +1,30 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+interface Base
+
+class Impl1 : Base
+
+class Impl2 : Base
+
+operator fun Base.plus(arg: Base) = Impl1()
+
+operator fun Impl2.plus(arg: Base) = Impl2()
+
+operator fun Base.plus(arg: Impl2) = Impl2()
+
+operator fun Base.unaryMinus() = Impl1()
+
+operator fun Impl2.unaryMinus() = Impl2()
+
+// See also KT-10384: in non-error functions, as is necessary!
+fun add1(x: Impl2, y: Base): Impl1 = x as Base + y
+
+fun error1(x: Impl2, y: Base): Impl1 = <!TYPE_MISMATCH!>x + y<!>
+
+fun add2(x: Base, y: Impl2): Impl1 = x + y as Base
+
+fun error2(x: Base, y: Impl2): Impl1 = <!TYPE_MISMATCH!>x + y<!>
+
+fun minus3(x: Impl2): Impl1 = -(x as Base)
+
+fun error3(x: Impl2): Impl1 = <!TYPE_MISMATCH!>-x<!>

compiler/testData/diagnostics/tests/cast/AsInBinaryUnary.txt

@@ -0,0 +1,33 @@
+package
+
+public fun add1(/*0*/ x: Impl2, /*1*/ y: Base): Impl1
+public fun add2(/*0*/ x: Base, /*1*/ y: Impl2): Impl1
+public fun error1(/*0*/ x: Impl2, /*1*/ y: Base): Impl1
+public fun error2(/*0*/ x: Base, /*1*/ y: Impl2): Impl1
+public fun error3(/*0*/ x: Impl2): Impl1
+public fun minus3(/*0*/ x: Impl2): Impl1
+public operator fun Base.plus(/*0*/ arg: Base): Impl1
+public operator fun Base.plus(/*0*/ arg: Impl2): Impl2
+public operator fun Impl2.plus(/*0*/ arg: Base): Impl2
+public operator fun Base.unaryMinus(): Impl1
+public operator fun Impl2.unaryMinus(): Impl2
+
+public interface Base {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Impl1 : Base {
+    public constructor Impl1()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Impl2 : Base {
+    public constructor Impl2()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/cast/AsInsideIn.kt

@@ -0,0 +1,20 @@
+// See also KT-10386 
+interface A
+class B : A
+fun foo1(list: List<A>, arg: B?): Boolean {
+    // contains(T): Boolean is deprecated
+    return arg <!DEPRECATION!>in<!> list
+}
+fun foo2(list: List<A>, arg: B?): Boolean {
+    // FAKE: no cast needed
+    return arg as A? in list
+}
+fun foo3(list: List<A>, arg: B?): Boolean {
+    // No warning but KNPE risk
+    return arg!! in list
+}
+// But
+fun foo4(list: List<A>, arg: B): Boolean {
+    // Ok
+    return arg in list
+}

compiler/testData/diagnostics/testsWithStdLib/cast/AsInsideIn.txt

@@ -0,0 +1,19 @@
+package
+
+public fun foo1(/*0*/ list: kotlin.List<A>, /*1*/ arg: B?): kotlin.Boolean
+public fun foo2(/*0*/ list: kotlin.List<A>, /*1*/ arg: B?): kotlin.Boolean
+public fun foo3(/*0*/ list: kotlin.List<A>, /*1*/ arg: B?): kotlin.Boolean
+public fun foo4(/*0*/ list: kotlin.List<A>, /*1*/ arg: B): kotlin.Boolean
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B : A {
+    public constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -2157,6 +2157,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("AsInBinaryUnary.kt")
+            public void testAsInBinaryUnary() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/cast/AsInBinaryUnary.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("constants.kt")
             public void testConstants() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/cast/constants.kt");

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java

@@ -568,6 +568,12 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/cast"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("AsInsideIn.kt")
+        public void testAsInsideIn() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/cast/AsInsideIn.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("IsArray.kt")
         public void testIsArray() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/cast/IsArray.kt");