Show error hint when trying to refactor synthesized function

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

@@ -21,10 +21,7 @@ import com.intellij.psi.PsiNameIdentifierOwner;
 import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
+import org.jetbrains.jet.lang.descriptors.*;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
-import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
-import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
 import org.jetbrains.jet.lang.diagnostics.Diagnostic;
 import org.jetbrains.jet.lang.diagnostics.DiagnosticWithParameters1;
 import org.jetbrains.jet.lang.diagnostics.DiagnosticWithParameters2;
@@ -41,6 +38,8 @@ import org.jetbrains.jet.plugin.refactoring.changeSignature.JetParameterInfo;
 
 import java.util.List;
 
+import static org.jetbrains.jet.lang.descriptors.CallableMemberDescriptor.Kind.SYNTHESIZED;
+
 public abstract class ChangeFunctionSignatureFix extends JetIntentionAction<PsiElement> {
     protected final PsiElement context;
     protected final FunctionDescriptor functionDescriptor;
@@ -186,6 +185,11 @@ public abstract class ChangeFunctionSignatureFix extends JetIntentionAction<PsiE
         if (functionDescriptor == null) {
             return null;
         }
+
+        if (functionDescriptor.getKind() == SYNTHESIZED) {
+            return null;
+        }
+
         BindingContext bindingContext =
                 AnalyzerFacadeWithCache.analyzeFileWithCache((JetFile) context.getContainingFile()).getBindingContext();
         if (descriptor instanceof ValueParameterDescriptor) {

idea/src/org/jetbrains/jet/plugin/refactoring/JetRefactoringBundle.properties

@@ -9,6 +9,7 @@ cannot.refactor.namespace.expression=Cannot intoduce namespace reference
 cannot.extract.method=Cannot find statements to extract
 cannot.find.class.to.extract=Cannot find class to extract method
 cannot.refactor.expression.should.have.inferred.type=Expression should have inferred type
+cannot.refactor.synthesized.function=Cannot refactor synthesized function ''{0}''
 
 error.wrong.caret.position.function.or.constructor.name=The caret should be positioned at the name of the function or constructor to be refactored.
 error.cant.refactor.vararg.functions=Can't refactor the function with variable arguments

idea/src/org/jetbrains/jet/plugin/refactoring/changeSignature/JetChangeSignatureHandler.java

@@ -32,10 +32,7 @@ import com.intellij.refactoring.util.CommonRefactoringUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.annotations.TestOnly;
-import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
+import org.jetbrains.jet.lang.descriptors.*;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
-import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
-import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.plugin.project.AnalyzerFacadeWithCache;
@@ -182,6 +179,12 @@ public class JetChangeSignatureHandler implements ChangeSignatureHandler {
                     return null;
                 }
             }
+            if (((FunctionDescriptor) descriptor).getKind() == SYNTHESIZED) {
+                String message = JetRefactoringBundle.message("cannot.refactor.synthesized.function", descriptor.getName());
+                CommonRefactoringUtil.showErrorHint(project, editor, message, REFACTORING_NAME, HelpID.CHANGE_SIGNATURE);
+                return null;
+            }
+
 
             return (FunctionDescriptor) descriptor;
         }

idea/testData/quickfix/changeSignature/afterNotAvailableForSynthesized.kt

@@ -0,0 +1,8 @@
+// "Add parameter to function 'component1'" "false"
+//ERROR: Too many arguments for internal final fun component1(): jet.Int defined in Data
+
+data class Data(val i: Int) {}
+
+fun usage(d: Data) {
+    d.component1(2)
+}

idea/testData/quickfix/changeSignature/beforeNotAvailableForSynthesized.kt

@@ -0,0 +1,8 @@
+// "Add parameter to function 'component1'" "false"
+//ERROR: Too many arguments for internal final fun component1(): jet.Int defined in Data
+
+data class Data(val i: Int) {}
+
+fun usage(d: Data) {
+    d.component1(<caret>2)
+}

idea/testData/refactoring/changeSignature/SynthesizedBefore.kt

@@ -0,0 +1,5 @@
+data class Data(val i: Int) {}
+
+fun usage(d: Data) {
+    d.<caret>component1()
+}

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

@@ -414,6 +414,11 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             doTest("idea/testData/quickfix/changeSignature/beforeLinearHierarchy.kt");
         }
         
+        @TestMetadata("beforeNotAvailableForSynthesized.kt")
+        public void testNotAvailableForSynthesized() throws Exception {
+            doTest("idea/testData/quickfix/changeSignature/beforeNotAvailableForSynthesized.kt");
+        }
+        
         @TestMetadata("beforeRemoveConstructorParameter.kt")
         public void testRemoveConstructorParameter() throws Exception {
             doTest("idea/testData/quickfix/changeSignature/beforeRemoveConstructorParameter.kt");

idea/tests/org/jetbrains/jet/plugin/refactoring/changeSignature/JetChangeSignatureTest.java

@@ -34,6 +34,7 @@ import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 import org.jetbrains.jet.plugin.PluginTestCaseBase;
 import org.jetbrains.jet.plugin.project.AnalyzerFacadeWithCache;
+import org.jetbrains.jet.plugin.refactoring.JetRefactoringBundle;
 
 import java.io.File;
 import java.util.ArrayList;
@@ -80,6 +81,17 @@ public class JetChangeSignatureTest extends LightCodeInsightTestCase {
         doTest(changeInfo);
     }
 
+    public void testSynthesized() throws Exception {
+        try {
+            getChangeInfo();
+        }
+        catch (CommonRefactoringUtil.RefactoringErrorHintException e) {
+            assertEquals(JetRefactoringBundle.message("cannot.refactor.synthesized.function", "component1"), e.getMessage());
+            return;
+        }
+        fail();
+    }
+
     public void testPreferContainedInClass() throws Exception {
         JetChangeInfo changeInfo = getChangeInfo();
         assertEquals("param", changeInfo.getNewParameters()[0].getName());