check return type of contains() and compareTo()

idea/src/org/jetbrains/kotlin/idea/inspections/OperatorModifierInspection.kt

@@ -19,6 +19,8 @@ package org.jetbrains.kotlin.idea.inspections
 import com.intellij.codeInspection.*
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.lexer.JetModifierKeywordToken
 import org.jetbrains.kotlin.lexer.JetTokens
 import org.jetbrains.kotlin.psi.JetModifierListOwner
@@ -51,9 +53,9 @@ public class OperatorModifierInspection : AbstractKotlinInspection(), CleanupLoc
             return true
         }
         if (arity == 1 && (name in OperatorConventions.BINARY_OPERATION_NAMES.values() ||
-             name in OperatorConventions.ASSIGNMENT_OPERATIONS.values () ||
-             name == OperatorConventions.CONTAINS ||
-             name == OperatorConventions.COMPARE_TO)) {
+                           name in OperatorConventions.ASSIGNMENT_OPERATIONS.values () ||
+                           (name == OperatorConventions.CONTAINS && isBooleanReturnType()) ||
+                           (name == OperatorConventions.COMPARE_TO && isIntReturnType()))) {
             return true
         }
         if (name == OperatorConventions.INVOKE) {
@@ -67,6 +69,14 @@ public class OperatorModifierInspection : AbstractKotlinInspection(), CleanupLoc
         }
         return false
     }
+
+    private fun JetNamedFunction.isIntReturnType(): Boolean {
+        return KotlinBuiltIns.isInt(analyze().getType(this) ?: return false)
+    }
+
+    private fun JetNamedFunction.isBooleanReturnType(): Boolean {
+        return KotlinBuiltIns.isBoolean(analyze().getType(this) ?: return false)
+    }
 }
 
 class AddModifierLocalQuickFix(val modifier: JetModifierKeywordToken) : LocalQuickFix {

idea/testData/quickfix/migration/operatorModifier/containsInt.kt

@@ -0,0 +1,7 @@
+// "Add 'operator' modifier" "false"
+// ACTION: Convert member to extension
+// ACTION: Convert to block body
+// ACTION: Remove explicit type specification
+class A {
+    fun <caret>contains(other: A): Int = -1
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -4195,6 +4195,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/migration/operatorModifier"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), true);
             }
 
+            @TestMetadata("containsInt.kt")
+            public void testContainsInt() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/migration/operatorModifier/containsInt.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("simple.kt")
             public void testSimple() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/migration/operatorModifier/simple.kt");