FIR IDE: add receiver parameter for callable lookup elements in completion

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/lookups/KotlinCallableLookupObject.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2010-2021 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.lookups
+
+abstract class KotlinCallableLookupObject: KotlinLookupObject {
+    abstract val renderedReceiverType: String?
+}

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/lookups/TailTextProvider.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2021 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.lookups
+
+import org.jetbrains.kotlin.idea.completion.KotlinIdeaCompletionBundle
+import org.jetbrains.kotlin.idea.completion.lookups.CompletionShortNamesRenderer.renderFunctionParameters
+import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtCallableSymbol
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtFunctionSymbol
+import org.jetbrains.kotlin.idea.frontend.api.types.KtFunctionalType
+
+internal object TailTextProvider {
+    fun KtAnalysisSession.getTailText(symbol: KtCallableSymbol): String = buildString {
+        if (symbol is KtFunctionSymbol) {
+            if (insertLambdaBraces(symbol)) {
+                append(" {...}")
+            } else {
+                append(renderFunctionParameters(symbol))
+            }
+        }
+        symbol.receiverType?.type?.let{ receiverType ->
+            val renderedType = receiverType.render(CompletionShortNamesRenderer.TYPE_RENDERING_OPTIONS)
+            append(KotlinIdeaCompletionBundle.message("presentation.tail.for.0", renderedType))
+        }
+    }
+
+    fun KtAnalysisSession.insertLambdaBraces(symbol: KtFunctionSymbol): Boolean {
+        val singleParam = symbol.valueParameters.singleOrNull()
+        return singleParam != null && !singleParam.hasDefaultValue && singleParam.annotatedType.type is KtFunctionalType
+    }
+}

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/lookups/factories/FunctionLookupElementFactory.kt

@@ -32,6 +32,10 @@ import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtTypeArgumentList
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.renderer.render
+import org.jetbrains.kotlin.idea.completion.lookups.TailTextProvider.getTailText
+import org.jetbrains.kotlin.idea.completion.lookups.TailTextProvider.insertLambdaBraces
+import org.jetbrains.kotlin.idea.completion.lookups.CompletionShortNamesRenderer.renderFunctionParameters
+import org.jetbrains.kotlin.idea.completion.lookups.CompletionShortNamesRenderer.TYPE_RENDERING_OPTIONS
 
 internal class FunctionLookupElementFactory {
     fun KtAnalysisSession.createLookup(
@@ -44,7 +48,8 @@ internal class FunctionLookupElementFactory {
             importStrategy = importStrategy,
             inputValueArguments = symbol.valueParameters.isNotEmpty(),
             insertEmptyLambda = insertLambdaBraces(symbol),
-            renderedFunctionParameters = with(CompletionShortNamesRenderer) { renderFunctionParameters(symbol) }
+            renderedFunctionParameters = renderFunctionParameters(symbol),
+            renderedReceiverType = symbol.receiverType?.type?.render(TYPE_RENDERING_OPTIONS)
         )
 
         val insertionHandler = when (insertionStrategy) {
@@ -65,14 +70,6 @@ internal class FunctionLookupElementFactory {
         }
     }
 
-    private fun KtAnalysisSession.getTailText(symbol: KtFunctionSymbol): String {
-        return if (insertLambdaBraces(symbol)) " {...}" else with(CompletionShortNamesRenderer) { renderFunctionParameters(symbol) }
-    }
-
-    private fun KtAnalysisSession.insertLambdaBraces(symbol: KtFunctionSymbol): Boolean {
-        val singleParam = symbol.valueParameters.singleOrNull()
-        return singleParam != null && !singleParam.hasDefaultValue && singleParam.annotatedType.type is KtFunctionalType
-    }
 
     companion object {
         private val LOG = logger<FunctionLookupElementFactory>()
@@ -88,8 +85,9 @@ private data class FunctionLookupObject(
     val inputValueArguments: Boolean,
     val insertEmptyLambda: Boolean,
     // for distinction between different overloads
-    private val renderedFunctionParameters: String
+    private val renderedFunctionParameters: String,
-) : KotlinLookupObject
+    override val renderedReceiverType: String?
+) : KotlinCallableLookupObject()
 
 
 private object FunctionInsertionHandler : QuotedNamesAwareInsertionHandler() {

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/lookups/factories/VariableLookupElementFactory.kt

@@ -13,6 +13,7 @@ import com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.idea.completion.lookups.*
 import org.jetbrains.kotlin.idea.completion.lookups.CallableImportStrategy
 import org.jetbrains.kotlin.idea.completion.lookups.KotlinLookupObject
+import org.jetbrains.kotlin.idea.completion.lookups.TailTextProvider.getTailText
 import org.jetbrains.kotlin.idea.completion.lookups.addCallableImportIfRequired
 import org.jetbrains.kotlin.idea.completion.lookups.detectImportStrategy
 import org.jetbrains.kotlin.idea.completion.lookups.shortenReferencesForFirCompletion
@@ -32,11 +33,13 @@ internal class VariableLookupElementFactory {
     ): LookupElementBuilder {
         val lookupObject = VariableLookupObject(
             symbol.name,
-            importStrategy = importStrategy
+            importStrategy = importStrategy,
+            renderedReceiverType = symbol.receiverType?.type?.render(CompletionShortNamesRenderer.TYPE_RENDERING_OPTIONS),
         )
 
         return LookupElementBuilder.create(lookupObject, symbol.name.asString())
             .withTypeText(symbol.annotatedType.type.render(KtTypeRendererOptions.SHORT_NAMES))
+            .withTailText(getTailText(symbol), true)
             .markIfSyntheticJavaProperty(symbol)
             .withInsertHandler(VariableInsertionHandler)
             .let { withSymbolInfo(symbol, it) }
@@ -61,8 +64,9 @@ internal class VariableLookupElementFactory {
  */
 private data class VariableLookupObject(
     override val shortName: Name,
-    val importStrategy: CallableImportStrategy
+    val importStrategy: CallableImportStrategy,
-) : KotlinLookupObject
+    override val renderedReceiverType: String?,
+) : KotlinCallableLookupObject()
 
 
 private object VariableInsertionHandler : InsertHandler<LookupElement> {