Completion: fix shortening of fully qualified name for case of conflicts between property and function

#KT-31902 Fixed
#KT-33937 Fixed

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/handlers/KotlinCallableInsertHandler.kt

@@ -22,7 +22,7 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 
 abstract class KotlinCallableInsertHandler(val callType: CallType<*>) : BaseDeclarationInsertHandler() {
     companion object {
-        private val shortenReferences = ShortenReferences { ShortenReferences.Options.DEFAULT.copy(dropBracesInStringTemplates = false) }
+        val SHORTEN_REFERENCES = ShortenReferences { ShortenReferences.Options.DEFAULT.copy(dropBracesInStringTemplates = false) }
     }
 
     override fun handleInsert(context: InsertionContext, item: LookupElement) {
@@ -54,7 +54,7 @@ abstract class KotlinCallableInsertHandler(val callType: CallType<*>) : BaseDecl
 
                 psiDocumentManager.commitAllDocuments()
 
-                shortenReferences.process(file, context.startOffset, context.tailOffset - 1)
+                SHORTEN_REFERENCES.process(file, context.startOffset, context.tailOffset - 1)
 
                 psiDocumentManager.doPostponedOperationsAndUnblockDocument(context.document)
 

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/handlers/KotlinFunctionInsertHandler.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
 package org.jetbrains.kotlin.idea.completion.handlers
@@ -29,9 +18,12 @@ import org.jetbrains.kotlin.idea.completion.LambdaSignatureTemplates
 import org.jetbrains.kotlin.idea.core.formatter.KotlinCodeStyleSettings
 import org.jetbrains.kotlin.idea.util.CallType
 import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtDotQualifiedExpression
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtTypeArgumentList
+import org.jetbrains.kotlin.psi.psiUtil.createSmartPointer
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
+import org.jetbrains.kotlin.psi.psiUtil.getLastParentOfTypeInRow
 import org.jetbrains.kotlin.types.KotlinType
 
 class GenerateLambdaInfo(val lambdaType: KotlinType, val explicitParameters: Boolean)
@@ -79,6 +71,18 @@ sealed class KotlinFunctionInsertHandler(callType: CallType<*>) : KotlinCallable
             val element = context.file.findElementAt(startOffset) ?: return
 
             addArguments(context, element)
+
+            // hack for KT-31902
+            if (callType == CallType.DEFAULT) {
+                context.file
+                    .findElementAt(startOffset)
+                    ?.parent?.getLastParentOfTypeInRow<KtDotQualifiedExpression>()
+                    ?.createSmartPointer()?.let {
+                        psiDocumentManager.commitDocument(document)
+                        val dotQualifiedExpression = it.element ?: return@let
+                        SHORTEN_REFERENCES.process(dotQualifiedExpression)
+                    }
+            }
         }
 
         private fun addArguments(context: InsertionContext, offsetElement: PsiElement) {
@@ -104,11 +108,12 @@ sealed class KotlinFunctionInsertHandler(callType: CallType<*>) : KotlinCallable
 
             var insertTypeArguments = inputTypeArguments && (isNormalCompletion || isReplaceCompletion || isSmartEnterCompletion)
 
+            val psiDocumentManager = PsiDocumentManager.getInstance(project)
             if (isReplaceCompletion) {
                 val offset1 = chars.skipSpaces(offset)
                 if (offset1 < chars.length) {
                     if (chars[offset1] == '<') {
-                        PsiDocumentManager.getInstance(project).commitDocument(document)
+                        psiDocumentManager.commitDocument(document)
                         val token = context.file.findElementAt(offset1)!!
                         if (token.node.elementType == KtTokens.LT) {
                             val parent = token.parent
@@ -159,7 +164,7 @@ sealed class KotlinFunctionInsertHandler(callType: CallType<*>) : KotlinCallable
                         document.insertString(offset, "()")
                     }
                 }
-                PsiDocumentManager.getInstance(project).commitDocument(document)
+                psiDocumentManager.commitDocument(document)
 
                 openingBracketOffset = document.charsSequence.indexOfSkippingSpace(openingBracket, offset)!!
                 closeBracketOffset = document.charsSequence.indexOfSkippingSpace(closingBracket, openingBracketOffset + 1)

idea/idea-completion/testData/handlers/multifile/PropertyFunctionConflict2-1.kt

@@ -0,0 +1,7 @@
+package a
+
+class Goo {
+    fun x() {
+        foo<caret>
+    }
+}

idea/idea-completion/testData/handlers/multifile/PropertyFunctionConflict2-2.kt

@@ -0,0 +1,5 @@
+package a.b
+
+val Foo.foo: Int get() = 123
+fun foo(i: (Int, Int) -> Unit) {}
+class Foo {}

idea/idea-completion/testData/handlers/multifile/PropertyFunctionConflict2.kt.after

@@ -0,0 +1,9 @@
+package a
+
+import a.b.foo
+
+class Goo {
+    fun x() {
+        foo { i, i2 ->  }
+    }
+}

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/CompletionMultifileHandlerTest.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.idea.completion.test.handlers
 
+import com.intellij.codeInsight.lookup.LookupElementPresentation
 import org.jetbrains.kotlin.idea.completion.test.COMPLETION_TEST_DATA_BASE_PATH
 import org.jetbrains.kotlin.idea.completion.test.KotlinCompletionTestCase
 import org.jetbrains.kotlin.test.JUnit3WithIdeaConfigurationRunner
@@ -73,6 +74,10 @@ class CompletionMultiFileHandlerTest : KotlinCompletionTestCase() {
         doTest()
     }
 
+    fun testPropertyFunctionConflict2() {
+        doTest(tailText = " { Int, Int -> ... } (i: (Int, Int) -> Unit) (a.b)")
+    }
+
     fun testExclCharInsertImport() {
         doTest('!')
     }
@@ -105,17 +110,26 @@ class CompletionMultiFileHandlerTest : KotlinCompletionTestCase() {
         doTest()
     }
 
-    fun doTest(completionChar: Char = '\n', vararg extraFileNames: String) {
+    fun doTest(completionChar: Char = '\n', vararg extraFileNames: String, tailText: String? = null) {
         val fileName = getTestName(false)
 
         configureByFiles(null, *extraFileNames)
-        configureByFiles(null, fileName + "-1.kt", fileName + "-2.kt")
+        configureByFiles(null, "$fileName-1.kt", "$fileName-2.kt")
         complete(2)
         if (myItems != null) {
-            val item = myItems.singleOrNull() ?: error("Multiple items in completion")
+            val item = if (tailText == null)
+                myItems.singleOrNull() ?: error("Multiple items in completion")
+            else {
+                val presentation = LookupElementPresentation()
+                myItems.first {
+                    it.renderElement(presentation)
+                    presentation.tailText == tailText
+                } ?: error("Tail text not found")
+            }
+
             selectItem(item, completionChar)
         }
-        checkResultByFile(fileName + ".kt.after")
+        checkResultByFile("$fileName.kt.after")
     }
 
     override fun getTestDataPath() = File(COMPLETION_TEST_DATA_BASE_PATH, "/handlers/multifile/").path + File.separator