New J2K: Add ConvertDataClass PostProcessing

idea/src/org/jetbrains/kotlin/idea/j2k/postProcessing/ConvertDataClass.kt

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.j2k.postProcessing
+
+import com.intellij.psi.impl.source.tree.PsiWhiteSpaceImpl
+import com.intellij.psi.search.LocalSearchScope
+import com.intellij.psi.search.searches.ReferencesSearch
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
+import org.jetbrains.kotlin.idea.core.setDefaultValue
+import org.jetbrains.kotlin.idea.j2k.J2kPostProcessing
+import org.jetbrains.kotlin.idea.references.KtSimpleNameReference
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.addRemoveModifier.setModifierList
+import org.jetbrains.kotlin.psi.psiUtil.asAssignment
+import org.jetbrains.kotlin.psi.psiUtil.containingClass
+import org.jetbrains.kotlin.resolve.diagnostics.Diagnostics
+
+class ConvertDataClass : J2kPostProcessing {
+    override val writeActionNeeded: Boolean = true
+
+    fun KtCallableDeclaration.rename(newName: String) {
+        val factory = KtPsiFactory(this)
+        ReferencesSearch.search(this, LocalSearchScope(containingKtFile)).forEach {
+            it.element.replace(factory.createExpression(newName))
+        }
+        setName(newName)
+    }
+
+    private data class DataClassInfo(
+        val constructorParameter: KtParameter,
+        val property: KtProperty,
+        val initBlockStatement: KtBinaryExpression
+    )
+
+    private fun collectPropertiesData(klass: KtClass): List<DataClassInfo> =
+        klass.getAnonymousInitializers()
+            .flatMap { (it.body as KtBlockExpression).statements }
+            .asSequence()
+            .mapNotNull { it.asAssignment() }
+            .mapNotNull { statement ->
+                val property =
+                    statement.left
+                        ?.unpackedReferenceToProperty()
+                        ?.takeIf { it.containingClass() == klass } ?: return@mapNotNull null
+                if (property.getter != null || property.setter != null) return@mapNotNull null
+                val constructorParameter =
+                    ((statement.right as? KtReferenceExpression)
+                        ?.references
+                        ?.firstOrNull { it is KtSimpleNameReference }
+                        ?.resolve() as? KtParameter)
+                        ?.takeIf {
+                            it.containingClass() == klass && !it.hasValOrVar()
+                        } ?: return@mapNotNull null
+
+                if (constructorParameter.type() != property.type()) return@mapNotNull null
+
+                DataClassInfo(constructorParameter, property, statement)
+            }.toList()
+
+    override fun createAction(element: KtElement, diagnostics: Diagnostics): (() -> Unit)? {
+        if (element !is KtClass) return null
+        return {
+            val factory = KtPsiFactory(element)
+            for ((constructorParameter, property, statement) in collectPropertiesData(element)) {
+                constructorParameter.addBefore(property.valOrVarKeyword, constructorParameter.nameIdentifier!!)
+                constructorParameter.addAfter(factory.createWhiteSpace(), constructorParameter.valOrVarKeyword!!)
+                constructorParameter.rename(property.name!!)
+                if (property.modifierList != null) {
+                    constructorParameter.setModifierList(property.modifierList!!)
+                }
+                property.delete()
+                statement.delete()
+            }
+            for (initBlock in element.getAnonymousInitializers()) {
+                if ((initBlock.body as KtBlockExpression).statements.isEmpty()) {
+                    initBlock.delete()
+                }
+            }
+        }
+    }
+}

idea/src/org/jetbrains/kotlin/idea/j2k/postProcessing/utils.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.j2k.postProcessing
+
+import com.intellij.psi.search.LocalSearchScope
+import com.intellij.psi.search.searches.ReferencesSearch
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
+import org.jetbrains.kotlin.idea.references.KtSimpleNameReference
+import org.jetbrains.kotlin.psi.*
+
+
+fun KtExpression.asProperty(): KtProperty? =
+    (this as? KtNameReferenceExpression)
+        ?.references
+        ?.firstOrNull { it is KtSimpleNameReference }
+        ?.resolve() as? KtProperty
+
+fun KtExpression.unpackedReferenceToProperty(): KtProperty? =
+    when (this) {
+        is KtDotQualifiedExpression ->
+            if (receiverExpression is KtThisExpression) selectorExpression as? KtNameReferenceExpression
+            else null
+        is KtNameReferenceExpression -> this
+        else -> null
+    }?.references
+        ?.firstOrNull { it is KtSimpleNameReference }
+        ?.resolve() as? KtProperty
+
+
+fun KtDeclaration.type() =
+    (resolveToDescriptorIfAny() as? CallableDescriptor)?.returnType