Smart completion: no more duplicates among type instantiation items

idea/src/org/jetbrains/jet/plugin/completion/SmartCompletion.kt

@@ -70,13 +70,12 @@ fun buildSmartCompletionData(expression: JetSimpleNameExpression, resolveSession
 
     if (receiver == null) {
         for (expectedType in expectedTypes) {
-            //TODO: there can be duplicates here for multiple expected types
-            typeInstantiationItems(expectedType, resolveSession, bindingContext).toCollection(additionalElements)
-
             //TODO: there can be duplicates here for multiple expected types
             staticMembers(expressionWithType, expectedType, resolveSession, bindingContext).toCollection(additionalElements)
         }
 
+        additionalElements.addTypeInstantiationItems(expectedTypes, resolveSession, bindingContext)
+
         thisItems(expressionWithType, expectedTypes, bindingContext).toCollection(additionalElements)
     }
 
@@ -204,18 +203,24 @@ private fun calcItemsToSkip(expression: JetExpression, resolveSession: ResolveSe
     return listOf()
 }
 
-private fun typeInstantiationItems(expectedType: ExpectedTypeInfo, resolveSession: ResolveSessionForBodies, bindingContext: BindingContext): Iterable<LookupElement> {
-    val typeConstructor: TypeConstructor = expectedType.`type`.getConstructor()
-    val classifier: ClassifierDescriptor? = typeConstructor.getDeclarationDescriptor()
-    if (!(classifier is ClassDescriptor)) return listOf()
+private fun MutableCollection<LookupElement>.addTypeInstantiationItems(expectedTypes: Collection<ExpectedTypeInfo>, resolveSession: ResolveSessionForBodies, bindingContext: BindingContext) {
+    val expectedTypesGrouped: Map<JetType, List<ExpectedTypeInfo>> = expectedTypes.groupBy { TypeUtils.makeNotNullable(it.`type`) }
+    for ((jetType, types) in expectedTypesGrouped) {
+        val tail = mergeTails(types.map { it.tail })
+        addTypeInstantiationItems(jetType, tail, resolveSession, bindingContext)
+    }
+}
 
+private fun MutableCollection<LookupElement>.addTypeInstantiationItems(jetType: JetType, tail: Tail?, resolveSession: ResolveSessionForBodies, bindingContext: BindingContext) {
+    val classifier = jetType.getConstructor().getDeclarationDescriptor()
+    if (!(classifier is ClassDescriptor)) return
     //TODO: check for constructor's visibility
 
     val lookupElement = DescriptorLookupConverter.createLookupElement(resolveSession, bindingContext, classifier)
 
     var lookupString = lookupElement.getLookupString()
 
-    val typeArgs = expectedType.`type`.getArguments()
+    val typeArgs = jetType.getArguments()
     var itemText = lookupString + DescriptorRenderer.TEXT.renderTypeArguments(typeArgs)
 
     val insertHandler: InsertHandler<LookupElement>
@@ -286,13 +291,13 @@ private fun typeInstantiationItems(expectedType: ExpectedTypeInfo, resolveSessio
         }
     }
 
-    val lookupElementWithTail = decorateLookupElement(lookupElementDecorated, expectedType.tail)
+    val lookupElementWithTail = decorateLookupElement(lookupElementDecorated, tail)
 
     if (suppressAutoInsertion) {
-        return listOf(AutoCompletionPolicy.NEVER_AUTOCOMPLETE.applyPolicy(lookupElementWithTail))
+        add(AutoCompletionPolicy.NEVER_AUTOCOMPLETE.applyPolicy(lookupElementWithTail))
     }
     else{
-        return listOf(lookupElementWithTail)
+        add(lookupElementWithTail)
     }
 }
 

idea/testData/completion/handlers/smart/MergeTail1.kt

@@ -0,0 +1,8 @@
+class C{}
+
+fun foo(c: C){}
+fun foo(c: C, i: Int){}
+
+fun foo() {
+    foo(<caret>
+}

idea/testData/completion/handlers/smart/MergeTail1.kt.after

@@ -0,0 +1,8 @@
+class C{}
+
+fun foo(c: C){}
+fun foo(c: C, i: Int){}
+
+fun foo() {
+    foo(C()<caret>
+}

idea/testData/completion/handlers/smart/MergeTail2.kt

@@ -0,0 +1,8 @@
+class C{}
+
+fun foo(c: C){}
+fun foo(c: C?, i: Int){}
+
+fun foo() {
+    foo(<caret>
+}

idea/testData/completion/handlers/smart/MergeTail2.kt.after

@@ -0,0 +1,8 @@
+class C{}
+
+fun foo(c: C){}
+fun foo(c: C?, i: Int){}
+
+fun foo() {
+    foo(C()<caret>
+}

idea/tests/org/jetbrains/jet/completion/handlers/SmartCompletionHandlerTestGenerated.java

@@ -16,11 +16,17 @@
 
 package org.jetbrains.jet.completion.handlers;
 
-import org.jetbrains.jet.JetTestUtils;
-import org.jetbrains.jet.test.TestMetadata;
+import junit.framework.Assert;
+import junit.framework.Test;
+import junit.framework.TestSuite;
 
 import java.io.File;
 import java.util.regex.Pattern;
+import org.jetbrains.jet.JetTestUtils;
+import org.jetbrains.jet.test.InnerTestClasses;
+import org.jetbrains.jet.test.TestMetadata;
+
+import org.jetbrains.jet.completion.handlers.AbstractSmartCompletionHandlerTest;
 
 /** This class is generated by {@link org.jetbrains.jet.generators.tests.TestsPackage}. DO NOT MODIFY MANUALLY */
 @SuppressWarnings("all")
@@ -180,6 +186,16 @@ public class SmartCompletionHandlerTestGenerated extends AbstractSmartCompletion
         doTest("idea/testData/completion/handlers/smart/JavaStaticMethodInsertsImport.kt");
     }
     
+    @TestMetadata("MergeTail1.kt")
+    public void testMergeTail1() throws Exception {
+        doTest("idea/testData/completion/handlers/smart/MergeTail1.kt");
+    }
+    
+    @TestMetadata("MergeTail2.kt")
+    public void testMergeTail2() throws Exception {
+        doTest("idea/testData/completion/handlers/smart/MergeTail2.kt");
+    }
+    
     @TestMetadata("TabReplaceComma1.kt")
     public void testTabReplaceComma1() throws Exception {
         doTest("idea/testData/completion/handlers/smart/TabReplaceComma1.kt");