Refactor and fix buildDecompiledText#appendDescriptor

Make it clear that first we render all enum entries, then the companion if it
exists, then anything else. Previously the companion wasn't rendered in the
case when the scope did not contain anything else (which was the case for the
scope of a class not found in the decompiler)

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/textBuilder/DecompiledTextFactory.kt

@@ -28,14 +28,12 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.renderer.DescriptorRendererModifier
 import org.jetbrains.kotlin.resolve.DescriptorUtils.isEnumEntry
-import org.jetbrains.kotlin.resolve.DescriptorUtils.isEnumClass
 import org.jetbrains.kotlin.resolve.dataClassUtils.isComponentLike
 import org.jetbrains.kotlin.resolve.descriptorUtil.secondaryConstructors
 import org.jetbrains.kotlin.types.error.MissingDependencyErrorClass
 import org.jetbrains.kotlin.types.flexibility
 import org.jetbrains.kotlin.types.isFlexible
-import java.util.ArrayList
+import java.util.*
-import java.util.HashMap
 
 private val FILE_ABI_VERSION_MARKER: String = "FILE_ABI"
 private val CURRENT_ABI_VERSION_MARKER: String = "CURRENT_ABI"
@@ -139,13 +137,13 @@ public fun buildDecompiledText(
         renderedDescriptorsToRange[descriptorToKey(descriptor)] = TextRange(startOffset, endOffset)
     }
 
-    fun appendDescriptor(descriptor: DeclarationDescriptor, indent: String, lastEnumEntry: Boolean = false) {
+    fun appendDescriptor(descriptor: DeclarationDescriptor, indent: String, lastEnumEntry: Boolean? = null) {
         if (descriptor is MissingDependencyErrorClass) {
             throw IllegalStateException("${descriptor.javaClass.getSimpleName()} cannot be rendered. FqName: ${descriptor.fullFqName}")
         }
         val startOffset = builder.length()
         val header = if (isEnumEntry(descriptor))
-            descriptor.name.asString() + if (lastEnumEntry) ";" else ","
+            descriptor.name.asString() + if (lastEnumEntry!!) ";" else ","
         else
             descriptorRenderer.render(descriptor).replace("= ...", DECOMPILED_COMMENT_FOR_PARAMETER)
         builder.append(header)
@@ -170,14 +168,12 @@ public fun buildDecompiledText(
                 endOffset = builder.length()
             }
         }
-        else if (descriptor is ClassDescriptor) {
+        else if (descriptor is ClassDescriptor && !isEnumEntry(descriptor)) {
-            if (!isEnumEntry(descriptor)) {
             builder.append(" {\n")
-                var firstPassed = false
+
             val subindent = indent + "    "
-                val allDescriptors = descriptor.secondaryConstructors + descriptor.getDefaultType().getMemberScope().getDescriptors()
+
-                val companionObject = descriptor.getCompanionObjectDescriptor()
+            var firstPassed = false
-                var companionNeeded = (companionObject != null)
             fun newlineExceptFirst() {
                 if (firstPassed) {
                     builder.append("\n")
@@ -186,22 +182,30 @@ public fun buildDecompiledText(
                     firstPassed = true
                 }
             }
-                val enumEntryCount = if (isEnumClass(descriptor)) allDescriptors.count { isEnumEntry(it) } else 0
+
-                var enumEntryIndex = 0
+            val allDescriptors = descriptor.secondaryConstructors + descriptor.defaultType.memberScope.getDescriptors()
-                for (member in allDescriptors) {
+            val (enumEntries, members) = allDescriptors.partition(::isEnumEntry)
+
+            for ((index, enumEntry) in enumEntries.withIndex()) {
+                newlineExceptFirst()
+                builder.append(subindent)
+                appendDescriptor(enumEntry, subindent, index == enumEntries.lastIndex)
+            }
+
+            val companionObject = descriptor.companionObjectDescriptor
+            if (companionObject != null) {
+                newlineExceptFirst()
+                builder.append(subindent)
+                appendDescriptor(companionObject, subindent)
+            }
+
+            for (member in members) {
                 if (member.containingDeclaration != descriptor) {
                     continue
                 }
                 if (member == companionObject) {
                     continue
                 }
-                    val isEnumEntry = isEnumEntry(member)
-                    if (companionNeeded && !isEnumEntry) {
-                        companionNeeded = false
-                        newlineExceptFirst()
-                        builder.append(subindent)
-                        appendDescriptor(companionObject!!, subindent)
-                    }
                 if (member is CallableMemberDescriptor
                     && member.kind != CallableMemberDescriptor.Kind.DECLARATION
                     //TODO: not synthesized and component like
@@ -210,18 +214,18 @@ public fun buildDecompiledText(
                 }
                 newlineExceptFirst()
                 builder.append(subindent)
-                    appendDescriptor(member, subindent, isEnumEntry && ++enumEntryIndex == enumEntryCount)
+                appendDescriptor(member, subindent)
             }
+
             builder.append(indent).append("}")
             endOffset = builder.length()
         }
-        }
 
         builder.append("\n")
         saveDescriptorToRange(descriptor, startOffset, endOffset)
 
         if (descriptor is ClassDescriptor) {
-            val primaryConstructor = descriptor.getUnsubstitutedPrimaryConstructor()
+            val primaryConstructor = descriptor.unsubstitutedPrimaryConstructor
             if (primaryConstructor != null) {
                 saveDescriptorToRange(primaryConstructor, startOffset, endOffset)
             }