IJPL-218636 [psi] send children-move events on moving file

GitOrigin-RevId: 5df2f1f7b007da16576e1d8604d845d7e044bd5d

platform/lang-impl/src/com/intellij/psi/impl/file/impl/PsiVFSListener.kt

@@ -451,24 +451,38 @@ private class PsiVFSListener(private val project: Project) {
     }
 
     ApplicationManager.getApplication().runWriteAction(ExternalChangeActionUtil.externalChangeAction {
-      val treeEvent = PsiTreeChangeEventImpl(manager)
       val isExcluded = vFile.isDirectory && Registry.`is`("ide.hide.excluded.files") && myProjectRootManager.fileIndex.isExcluded(vFile)
       if (oldParentDir != null && !isExcluded) {
-        val eventChild = if (vFile.isDirectory) fileManager.findDirectory(vFile) else fileManager.findFile(vFile)
-        treeEvent.child = eventChild
-        if (newParentDir != null) {
-          treeEvent.oldParent = oldParentDir
-          treeEvent.newParent = newParentDir
-          manager.beforeChildMovement(treeEvent)
+
+        // a list of:
+        // - one or several not-null PsiFiles
+        // - one not-null PsiDirectory
+        // - single 'null' if corresponding PsiDirectory or PsiFile cannot be created
+        val eventChildren: List<PsiFileSystemItem?> = if (vFile.isDirectory) {
+          listOf(fileManager.findDirectory(vFile))
         }
         else {
-          treeEvent.parent = oldParentDir
-          manager.beforeChildRemoval(treeEvent)
+          fileManager.getCachedPsiFiles(vFile).ifEmpty { listOf(fileManager.findFile(vFile)) }
+        }
+
+        for (eventChild in eventChildren) {
+          val treeEvent = PsiTreeChangeEventImpl(manager)
+          treeEvent.child = eventChild
+          if (newParentDir != null) {
+            treeEvent.oldParent = oldParentDir
+            treeEvent.newParent = newParentDir
+            manager.beforeChildMovement(treeEvent)
+          }
+          else {
+            treeEvent.parent = oldParentDir
+            manager.beforeChildRemoval(treeEvent)
+          }
         }
       }
       else {
         // checked above
         LOG.assertTrue(newParentDir != null)
+        val treeEvent = PsiTreeChangeEventImpl(manager)
         treeEvent.parent = newParentDir
         manager.beforeChildAddition(treeEvent)
       }

platform/lang-impl/testSources/com/intellij/psi/impl/file/impl/MultiversePsiEventTest.kt

@@ -40,6 +40,7 @@ internal class MultiversePsiEventTest {
     private val module2 = projectFixture.moduleFixture("m2")
 
     private val sourceRoot = sharedSourceRootFixture(module1, module2)
+    private val sourceRoot2 = sharedSourceRootFixture(module1, module2)
 
     @Suppress("unused")
     private val registerFakeLang = testFixture {
@@ -266,6 +267,21 @@ internal class MultiversePsiEventTest {
     expectedEventNumber = 2
   )
 
+  @Test
+  fun `test we receive 2 before-child-moved events on moving a file with 2 psi files`() = doChangeTest(
+    listenerFactory = { counter ->
+      object : PsiTreeChangeAdapter() {
+        override fun beforeChildMovement(event: PsiTreeChangeEvent) {
+          counter.incrementAndGet()
+        }
+      }
+    },
+    updateBlock = { file ->
+      file.move(this, sourceRoot2.get().virtualFile)
+    },
+    expectedEventNumber = 2
+  )
+
   private fun doChangeTest(
     listenerFactory: (AtomicInteger) -> PsiTreeChangeListener,
     updateBlock: (file: VirtualFile) -> Unit,