Fixed not working item in completion list for infix call

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -127,27 +127,35 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
 
     protected val referenceVariantsHelper: ReferenceVariantsHelper = ReferenceVariantsHelper(bindingContext) { isVisibleDescriptor(it) }
 
+    protected val receiversData: ReferenceVariantsHelper.ReceiversData? = reference?.let { referenceVariantsHelper.getReferenceVariantsReceivers(it.expression) }
+
     protected val lookupElementFactory: LookupElementFactory = run {
-        val receiverTypes = if (reference != null) {
-            val expression = reference.expression
-            val (receivers, callType) = referenceVariantsHelper.getReferenceVariantsReceivers(expression)
+        if (receiversData != null) {
             val dataFlowInfo = bindingContext.getDataFlowInfo(expression)
-            var receiverTypes = receivers.flatMap {
+
+            var receiverTypes = receiversData.receivers.flatMap {
                 SmartCastUtils.getSmartCastVariantsWithLessSpecificExcluded(it, bindingContext, moduleDescriptor, dataFlowInfo)
             }
-            if (callType == CallType.SAFE) {
+
+            if (receiversData.callType == CallType.SAFE) {
                 receiverTypes = receiverTypes.map { it.makeNotNullable() }
             }
-            receiverTypes
+
+            LookupElementFactory(receiverTypes)
         }
         else {
-            listOf()
+            LookupElementFactory(emptyList())
         }
-        LookupElementFactory(receiverTypes)
     }
 
-    protected val collector: LookupElementsCollector = LookupElementsCollector(
-            prefixMatcher, parameters, resolutionFacade, lookupElementFactory, inDescriptor, expression?.getParent() is JetSimpleNameStringTemplateEntry)
+    private val collectorContext = if (expression?.getParent() is JetSimpleNameStringTemplateEntry)
+        LookupElementsCollector.Context.STRING_TEMPLATE_AFTER_DOLLAR
+    else if (receiversData?.callType == CallType.INFIX)
+        LookupElementsCollector.Context.INFIX_CALL
+    else
+        LookupElementsCollector.Context.NORMAL
+
+    protected val collector: LookupElementsCollector = LookupElementsCollector(prefixMatcher, parameters, resolutionFacade, lookupElementFactory, inDescriptor, collectorContext)
 
     protected val project: Project = position.getProject()
 

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionUtils.kt

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.ResolutionFacade
 import org.jetbrains.kotlin.idea.completion.handlers.CastReceiverInsertHandler
 import org.jetbrains.kotlin.idea.completion.handlers.WithTailInsertHandler
 import org.jetbrains.kotlin.idea.util.FuzzyType
+import org.jetbrains.kotlin.idea.util.fuzzyReturnType
 import org.jetbrains.kotlin.idea.util.getImplicitReceiversWithInstance
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt

@@ -39,8 +39,14 @@ class LookupElementsCollector(
         private val resolutionFacade: ResolutionFacade,
         private val lookupElementFactory: LookupElementFactory,
         private val inDescriptor: DeclarationDescriptor?,
-        private val surroundCallsWithBraces: Boolean
+        private val context: LookupElementsCollector.Context
 ) {
+    public enum class Context {
+        NORMAL
+        STRING_TEMPLATE_AFTER_DOLLAR
+        INFIX_CALL
+    }
+
     private val elements = ArrayList<LookupElement>()
 
     public fun flushToResultSet(resultSet: CompletionResultSet) {
@@ -63,7 +69,7 @@ class LookupElementsCollector(
         }
     }
 
-    public fun addDescriptorElements(descriptor: DeclarationDescriptor, suppressAutoInsertion: Boolean, withReceiverCast: Boolean) {
+    private fun addDescriptorElements(descriptor: DeclarationDescriptor, suppressAutoInsertion: Boolean, withReceiverCast: Boolean) {
         run {
             var lookupElement = lookupElementFactory.createLookupElement(resolutionFacade, descriptor, true)
 
@@ -71,7 +77,7 @@ class LookupElementsCollector(
                 lookupElement = lookupElement.withReceiverCast()
             }
 
-            if (surroundCallsWithBraces && (descriptor is FunctionDescriptor || descriptor is ClassifierDescriptor)) {
+            if (context == Context.STRING_TEMPLATE_AFTER_DOLLAR && (descriptor is FunctionDescriptor || descriptor is ClassifierDescriptor)) {
                 lookupElement = lookupElement.withBracesSurrounding()
             }
 
@@ -84,7 +90,7 @@ class LookupElementsCollector(
         }
 
         // add special item for function with one argument of function type with more than one parameter
-        if (descriptor is FunctionDescriptor) {
+        if (context != Context.INFIX_CALL && descriptor is FunctionDescriptor) {
             val parameters = descriptor.getValueParameters()
             if (parameters.size() == 1) {
                 val parameterType = parameters.get(0).getType()
@@ -108,7 +114,7 @@ class LookupElementsCollector(
                             }
                         }
 
-                        if (surroundCallsWithBraces) {
+                        if (context == Context.STRING_TEMPLATE_AFTER_DOLLAR) {
                             lookupElement = lookupElement.withBracesSurrounding()
                         }
 
@@ -121,10 +127,10 @@ class LookupElementsCollector(
         if (descriptor is PropertyDescriptor) {
             var lookupElement = lookupElementFactory.createBackingFieldLookupElement(descriptor, inDescriptor, resolutionFacade)
             if (lookupElement != null) {
-                if (surroundCallsWithBraces) {
-                    lookupElement = lookupElement!!.withBracesSurrounding()
+                if (context == Context.STRING_TEMPLATE_AFTER_DOLLAR) {
+                    lookupElement = lookupElement.withBracesSurrounding()
                 }
-                addElement(lookupElement!!)
+                addElement(lookupElement)
             }
         }
     }

idea/idea-completion/testData/basic/common/InfixCallNoSpecialLambdaArgumentItem.kt

@@ -0,0 +1,11 @@
+// checks that no special item "ext1 { String, Int -> ... }" created for infix call
+fun Int.ext1(handler: (String, Int) -> Unit){}
+fun Int.ext2(c: Char){}
+
+fun foo() {
+    val pair = 1 ext<caret>
+}
+
+// EXIST: ext1
+// EXIST: ext2
+// NUMBER: 2

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JSBasicCompletionTestGenerated.java

@@ -631,6 +631,12 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             doTest(fileName);
         }
 
+        @TestMetadata("InfixCallNoSpecialLambdaArgumentItem.kt")
+        public void testInfixCallNoSpecialLambdaArgumentItem() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InfixCallNoSpecialLambdaArgumentItem.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("InsideAnonymousClass.kt")
         public void testInsideAnonymousClass() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InsideAnonymousClass.kt");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -631,6 +631,12 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("InfixCallNoSpecialLambdaArgumentItem.kt")
+        public void testInfixCallNoSpecialLambdaArgumentItem() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InfixCallNoSpecialLambdaArgumentItem.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("InsideAnonymousClass.kt")
         public void testInsideAnonymousClass() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InsideAnonymousClass.kt");