Quickfix for COMPARE_TO_TYPE_MISMATCH

idea/src/org/jetbrains/jet/plugin/quickfix/ChangeFunctionReturnTypeFix.java

@@ -26,6 +26,7 @@ import com.intellij.psi.PsiFile;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
 import org.jetbrains.jet.lang.descriptors.SimpleFunctionDescriptor;
 import org.jetbrains.jet.lang.diagnostics.Diagnostic;
@@ -131,4 +132,22 @@ public class ChangeFunctionReturnTypeFix extends JetIntentionAction<JetFunction>
             }
         };
     }
+
+    @NotNull
+    public static JetIntentionActionFactory createFactoryForCompareToTypeMismatch() {
+        return new JetIntentionActionFactory() {
+            @Nullable
+            @Override
+            public IntentionAction createAction(Diagnostic diagnostic) {
+                JetBinaryExpression expression = QuickFixUtil.getParentElementOfType(diagnostic, JetBinaryExpression.class);
+                assert expression != null : "COMPARE_TO_TYPE_MISMATCH reported on element that is not within any expression";
+                BindingContext context = AnalyzerFacadeWithCache.analyzeFileWithCache((JetFile) expression.getContainingFile()).getBindingContext();
+                ResolvedCall<? extends CallableDescriptor> resolvedCall = context.get(BindingContext.RESOLVED_CALL, expression.getOperationReference());
+                if (resolvedCall == null) return null;
+                PsiElement compareTo = BindingContextUtils.descriptorToDeclaration(context, resolvedCall.getCandidateDescriptor());
+                if (!(compareTo instanceof JetFunction)) return null;
+                return new ChangeFunctionReturnTypeFix((JetFunction) compareTo, KotlinBuiltIns.getInstance().getIntType());
+            }
+        };
+    }
 }

idea/src/org/jetbrains/jet/plugin/quickfix/QuickFixes.java

@@ -214,6 +214,7 @@ public class QuickFixes {
         factories.put(PROPERTY_TYPE_MISMATCH_ON_OVERRIDE, ChangePropertyTypeToMatchOverriddenPropertyFix.createFactory());
         factories.put(COMPONENT_FUNCTION_RETURN_TYPE_MISMATCH, ChangeFunctionReturnTypeFix.createFactoryForComponentFunctionReturnTypeMismatch());
         factories.put(HAS_NEXT_FUNCTION_TYPE_MISMATCH, ChangeFunctionReturnTypeFix.createFactoryForHasNextFunctionTypeMismatch());
+        factories.put(COMPARE_TO_TYPE_MISMATCH, ChangeFunctionReturnTypeFix.createFactoryForCompareToTypeMismatch());
 
         factories.put(PLATFORM_CLASS_MAPPED_TO_KOTLIN, MapPlatformClassToKotlinFix.createFactory());
     }

idea/testData/quickfix/typeMismatch/afterCompareToTypeMismatch.kt

@@ -0,0 +1,7 @@
+// "Change 'A.compareTo' function return type to 'Int'" "true"
+trait A {
+    fun compareTo(other: Any): Int
+}
+fun foo(x: A) {
+    if (x <<caret> 0) {}
+}

idea/testData/quickfix/typeMismatch/beforeCompareToTypeMismatch.kt

@@ -0,0 +1,7 @@
+// "Change 'A.compareTo' function return type to 'Int'" "true"
+trait A {
+    fun compareTo(other: Any): String
+}
+fun foo(x: A) {
+    if (x <<caret> 0) {}
+}

idea/tests/org/jetbrains/jet/plugin/quickfix/QuickFixTestGenerated.java

@@ -977,6 +977,11 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         public void testChangeReturnTypeWhenValueParameterListIsAbsent() throws Exception {
             doTest("idea/testData/quickfix/typeMismatch/beforeChangeReturnTypeWhenValueParameterListIsAbsent.kt");
         }
+
+        @TestMetadata("beforeCompareToTypeMismatch.kt")
+        public void testCompareToTypeMismatch() throws Exception {
+            doTest("idea/testData/quickfix/typeMismatch/beforeCompareToTypeMismatch.kt");
+        }
         
         @TestMetadata("beforeComponentFunctionReturnTypeMismatch1.kt")
         public void testComponentFunctionReturnTypeMismatch1() throws Exception {