From 307586e435f14ff41ee36c1322f7863bf441001b Mon Sep 17 00:00:00 2001
From: Nikolay Krasko <nikolay.krasko@jetbrains.com>
Date: Thu, 6 Sep 2018 12:27:58 +0300
Subject: [PATCH] Don't show types for enum entries with enum name is present
 in initializer (KT-26057)

 #KT-26057 Fixed
---
 .../org/jetbrains/kotlin/types/TypeUtils.kt   |  1 +
 .../kotlin/idea/parameterInfo/TypeHints.kt    | 55 +++++++++------
 .../idea/parameterInfo/InlayTypeHintsTest.kt  | 70 +++++++++++++++++++
 3 files changed, 105 insertions(+), 21 deletions(-)

diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt b/core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt
index 3cc66395b81..1a8bffe936a 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt
@@ -77,6 +77,7 @@ fun KotlinType.isPrimitiveNumberOrNullableType(): Boolean =
 fun KotlinType.isTypeParameter(): Boolean = TypeUtils.isTypeParameter(this)
 
 fun KotlinType.isInterface(): Boolean = (constructor.declarationDescriptor as? ClassDescriptor)?.kind == ClassKind.INTERFACE
+fun KotlinType.isEnum(): Boolean = (constructor.declarationDescriptor as? ClassDescriptor)?.kind == ClassKind.ENUM_CLASS
 
 fun KotlinType?.isArrayOfNothing(): Boolean {
     if (this == null || !KotlinBuiltIns.isArray(this)) return false
diff --git a/idea/src/org/jetbrains/kotlin/idea/parameterInfo/TypeHints.kt b/idea/src/org/jetbrains/kotlin/idea/parameterInfo/TypeHints.kt
index 4945d8ba5c0..3259e4ba997 100644
--- a/idea/src/org/jetbrains/kotlin/idea/parameterInfo/TypeHints.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/parameterInfo/TypeHints.kt
@@ -8,15 +8,13 @@ package org.jetbrains.kotlin.idea.parameterInfo
 import com.intellij.codeInsight.hints.InlayInfo
 import com.intellij.psi.PsiElement
 import com.intellij.psi.codeStyle.CodeStyleSettingsManager
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
-import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
-import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToCall
 import org.jetbrains.kotlin.idea.core.formatter.KotlinCodeStyleSettings
 import org.jetbrains.kotlin.idea.intentions.SpecifyTypeExplicitlyIntention
+import org.jetbrains.kotlin.idea.references.resolveMainReferenceToDescriptors
 import org.jetbrains.kotlin.idea.util.getResolutionScope
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.load.java.sam.SamConstructorDescriptor
@@ -28,6 +26,7 @@ import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.renderer.RenderingFormat
 import org.jetbrains.kotlin.renderer.renderFqName
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.descriptorUtil.isCompanionObject
 import org.jetbrains.kotlin.resolve.descriptorUtil.parentsWithSelf
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
@@ -35,6 +34,7 @@ import org.jetbrains.kotlin.resolve.scopes.utils.findClassifier
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.typeUtil.containsError
 import org.jetbrains.kotlin.types.typeUtil.immediateSupertypes
+import org.jetbrains.kotlin.types.typeUtil.isEnum
 
 //hack to separate type presentation from param info presentation
 const val TYPE_INFO_PREFIX = "@TYPE@"
@@ -106,11 +106,13 @@ fun provideTypeHint(element: KtCallableDeclaration, offset: Int): List<InlayInfo
 
         val declString = buildString {
             append(TYPE_INFO_PREFIX)
-            if (settings.SPACE_BEFORE_TYPE_COLON)
+            if (settings.SPACE_BEFORE_TYPE_COLON) {
                 append(" ")
+            }
             append(":")
-            if (settings.SPACE_AFTER_TYPE_COLON)
+            if (settings.SPACE_AFTER_TYPE_COLON) {
                 append(" ")
+            }
             append(getInlayHintsTypeRenderer(element.analyze(), element).renderType(type))
         }
         listOf(InlayInfo(declString, offset))
@@ -120,21 +122,32 @@ fun provideTypeHint(element: KtCallableDeclaration, offset: Int): List<InlayInfo
 }
 
 private fun isUnclearType(type: KotlinType, element: KtCallableDeclaration): Boolean {
-    if (element is KtProperty) {
-        val initializer = element.initializer ?: return true
-        if (initializer is KtConstantExpression || initializer is KtStringTemplateExpression) return false
-        if (initializer is KtUnaryExpression && initializer.baseExpression is KtConstantExpression) return false
-        if (initializer is KtCallExpression) {
-            val resolvedCall = initializer.resolveToCall(BodyResolveMode.FULL)
-            val resolvedDescriptor = resolvedCall?.candidateDescriptor
-            if (resolvedDescriptor is SamConstructorDescriptor) {
-                return false
-            }
-            if (resolvedDescriptor is ConstructorDescriptor &&
-                (resolvedDescriptor.constructedClass.declaredTypeParameters.isEmpty() || initializer.typeArgumentList != null)) {
-                return false
-            }
+    if (element !is KtProperty) return true
+
+    val initializer = element.initializer ?: return true
+    if (initializer is KtConstantExpression || initializer is KtStringTemplateExpression) return false
+    if (initializer is KtUnaryExpression && initializer.baseExpression is KtConstantExpression) return false
+    if (initializer is KtCallExpression) {
+        val resolvedCall = initializer.resolveToCall(BodyResolveMode.FULL)
+        val resolvedDescriptor = resolvedCall?.candidateDescriptor
+        if (resolvedDescriptor is SamConstructorDescriptor) {
+            return false
+        }
+        if (resolvedDescriptor is ConstructorDescriptor &&
+            (resolvedDescriptor.constructedClass.declaredTypeParameters.isEmpty() || initializer.typeArgumentList != null)) {
+            return false
         }
     }
+
+    if (type.isEnum() && initializer is KtDotQualifiedExpression) {
+        // Do not show type for enums if initializer has enum entry with explicit enum name: val p = Enum.ENTRY
+        val enumEntrySelector = initializer.selectorExpression
+        val enumEntryDescriptor: DeclarationDescriptor? = enumEntrySelector?.resolveMainReferenceToDescriptors()?.singleOrNull()
+
+        if (enumEntryDescriptor != null && DescriptorUtils.isEnumEntry(enumEntryDescriptor)) {
+            return false
+        }
+    }
+
     return true
-}
\ No newline at end of file
+}
diff --git a/idea/tests/org/jetbrains/kotlin/idea/parameterInfo/InlayTypeHintsTest.kt b/idea/tests/org/jetbrains/kotlin/idea/parameterInfo/InlayTypeHintsTest.kt
index b2d7d9c82eb..e89296322cc 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/parameterInfo/InlayTypeHintsTest.kt
+++ b/idea/tests/org/jetbrains/kotlin/idea/parameterInfo/InlayTypeHintsTest.kt
@@ -98,6 +98,76 @@ class InlayTypeHintsTest : KotlinLightCodeInsightFixtureTestCase() {
         )
     }
 
+    fun testEnumEntry() {
+        checkPropertyHint(
+            """
+            enum class E { ENTRY }
+            val test = E.ENTRY
+            """.trimIndent()
+        )
+    }
+
+    fun testEnumEntryLikeProperty() {
+        checkPropertyHint(
+            """
+            enum class E {
+                ENTRY;
+                companion object {
+                    val test: E = ENTRY
+                }
+            }
+
+            val test<hint text=": E"/> = E.test
+            """.trimIndent()
+        )
+    }
+
+    fun testEnumEntryLikeFunction() {
+        checkPropertyHint(
+            """
+            enum class E { ENTRY;
+                companion object {
+                    fun test(): E = ENTRY
+                }
+            }
+
+            val test<hint text=": E"/> = E.test()
+            """.trimIndent()
+        )
+    }
+
+    fun testImportedEnumEntry() {
+        checkPropertyHint(
+            """
+            import E.ENTRY
+            enum class E { ENTRY }
+            val test<hint text=": E"/> = ENTRY
+            """.trimIndent()
+        )
+    }
+
+    fun testEnumEntryCompanion() {
+        checkPropertyHint(
+            """
+            enum class E {
+                ENTRY;
+                companion object {}
+            }
+            val test<hint text=": E"/> = E.Companion
+            """
+        )
+    }
+
+    fun testEnumEntryQualified() {
+        checkPropertyHint(
+            """
+            package a
+            enum class E { ENTRY }
+            val test = a.E.ENTRY
+            """
+        )
+    }
+
     fun testDestructuring() {
         checkLocalVariable(
             """