[workspace model] Add inspection to check that all fields are immutable in inheritors of WorkspaceEntity interface

GitOrigin-RevId: f9e164b80a98a248b89f5508f0a3bdcaa0c5494c

plugins/devkit/intellij.devkit.workspaceModel/resources/inspectionDescriptions/WorkspaceEntityMutableField.html

@@ -0,0 +1,9 @@
+<html>
+<body>
+Detects unsupported <code>var</code> fields in the inheritors of <code>WorkspaceEntity</code> interface
+<p>
+  Interface implementing <code>WorkspaceEntity</code> have to have only <code>val</code> fields because it's immutable.
+  Implementation of <code>WorkspaceEntity.Builder</code> will be generated for the mutation
+</p>
+</body>
+</html>

plugins/devkit/intellij.devkit.workspaceModel/resources/intellij.devkit.workspaceModel.xml

@@ -30,5 +30,12 @@
                      enabledByDefault="true" level="WARNING"
                      implementationClass="com.intellij.devkit.workspaceModel.WorkspaceImplAbsentInspection"
                      key="inspection.workspace.absent.model.display.name"/>
+    <localInspection language="kotlin"
+                     groupBundle="messages.DevKitWorkspaceModelBundle"
+                     groupPathKey="inspections.group.path" groupKey="inspections.group.workspace.model"
+                     runForWholeFile="true"
+                     enabledByDefault="true" level="WARNING"
+                     implementationClass="com.intellij.devkit.workspaceModel.WorkspaceEntityMutableFieldInspection"
+                     key="inspection.workspace.mutable.field.display.name"/>
   </extensions>
 </idea-plugin>

plugins/devkit/intellij.devkit.workspaceModel/resources/messages/DevKitWorkspaceModelBundle.properties

@@ -6,6 +6,8 @@ inspection.workspace.msg.obsolete.implementation=Obsolete entity implementation
 inspection.workspace.msg.regenerate.implementation=Regenerate implementation
 inspection.workspace.absent.model.display.name=Absent entity implementation
 inspection.workspace.msg.generate.implementation=Generate implementation
+inspection.workspace.mutable.field.display.name=Unsupported 'var' field in entity
+inspection.workspace.msg.change.field.to.val=Change to 'val'
 
 progress.title.generating.code=Generating code
 progress.text.removing.old.code=Removing old code

plugins/devkit/intellij.devkit.workspaceModel/src/WorkspaceEntityMutableFieldInspection.kt

@@ -0,0 +1,37 @@
+// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.devkit.workspaceModel
+
+import com.intellij.codeInspection.*
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.psi.KtClass
+import org.jetbrains.kotlin.psi.KtProperty
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.psi.KtVisitorVoid
+
+class WorkspaceEntityMutableFieldInspection: LocalInspectionTool() {
+  override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean) = object : KtVisitorVoid() {
+    override fun visitClass(klass: KtClass) {
+      if (!klass.isWorkspaceEntity()) return
+      if (klass.name == "Builder") return
+      klass.getProperties().forEach { property ->
+        if (property.isVar) {
+          holder.registerProblem(property, DevKitWorkspaceModelBundle.message("inspection.workspace.mutable.field.display.name"),
+                                 ProblemHighlightType.GENERIC_ERROR, MakeFieldImmutableFix())
+        }
+      }
+    }
+  }
+}
+
+private class MakeFieldImmutableFix : LocalQuickFix {
+  override fun getName() = DevKitWorkspaceModelBundle.message("inspection.workspace.msg.change.field.to.val")
+  override fun getFamilyName() = name
+  override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+    val psiElement = descriptor.psiElement
+    if (!psiElement.isValid) return
+    if (psiElement !is KtProperty) return
+
+    val factory = KtPsiFactory(project)
+    psiElement.valOrVarKeyword.replace(factory.createValKeyword())
+  }
+}