[java] clear deletion of reference expression qualifiers (IDEA-184557)

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiReferenceExpressionImpl.java

@@ -21,6 +21,7 @@ import com.intellij.psi.impl.PsiManagerEx;
 import com.intellij.psi.impl.source.PsiJavaCodeReferenceElementImpl;
 import com.intellij.psi.impl.source.SourceJavaCodeReference;
 import com.intellij.psi.impl.source.SourceTreeToPsiMap;
+import com.intellij.psi.impl.source.codeStyle.CodeEditUtil;
 import com.intellij.psi.impl.source.resolve.*;
 import com.intellij.psi.impl.source.tree.*;
 import com.intellij.psi.infos.CandidateInfo;
@@ -722,9 +723,19 @@ public class PsiReferenceExpressionImpl extends ExpressionPsiElement implements
   @Override
   public void deleteChildInternal(@NotNull ASTNode child) {
     if (getChildRole(child) == ChildRole.QUALIFIER) {
-      ASTNode dot = findChildByRole(ChildRole.DOT);
-      super.deleteChildInternal(child);
-      deleteChildInternal(dot);
+      ASTNode dot = findChildByType(JavaTokenType.DOT, child);
+      assert dot != null : this;
+      deleteChildRange(child.getPsi(), dot.getPsi());
+
+      ASTNode first = getFirstChildNode();
+      if (getChildRole(first) == ChildRole.REFERENCE_PARAMETER_LIST && first.getFirstChildNode() == null) {
+        ASTNode start = first.getTreeNext();
+        if (PsiImplUtil.isWhitespaceOrComment(start)) {
+          ASTNode next = PsiImplUtil.skipWhitespaceAndComments(start);
+          assert next != null : this;
+          CodeEditUtil.removeChildren(this, start, next.getTreePrev());
+        }
+      }
     }
     else if (child.getElementType() == JavaElementType.REFERENCE_PARAMETER_LIST) {
       replaceChildInternal(child, createEmptyRefParameterList(getProject()));

java/java-tests/testData/codeInsight/completion/invokeHandle/VirtualType.java

@@ -3,6 +3,6 @@ import java.lang.invoke.*;
 public class Main {
   void foo() throws Throwable {
     MethodHandles.Lookup lookup = MethodHandles.lookup();
-    lookup.findVirtual(Types.class, "strMethod",<caret>);
+    lookup.findVirtual(Types.class, "strMethod", <caret>);
   }
 }

java/java-tests/testSrc/com/intellij/java/psi/JavaPsiTest.groovy

@@ -1,4 +1,6 @@
-// Copyright 2000-2017 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+ */
 package com.intellij.java.psi
 
 import com.intellij.openapi.command.WriteCommandAction
@@ -51,6 +53,22 @@ class JavaPsiTest extends LightCodeInsightFixtureTestCase {
     assert statement.text == "exports pkg;"
   }
 
+  void testReferenceQualifierDeletion() {
+    def file = configureFile("class C {\n  Qualifier /*comment*/ . /*another*/ ref r;\n}")
+    def ref = file.classes[0].fields[0].typeElement.firstChild
+    assert ref != null
+    runCommand { ref.firstChild.delete() }
+    assert ref.text == "ref"
+  }
+
+  void testExpressionQualifierDeletion() {
+    def file = configureFile("class C {\n  Object o = qualifier /*comment*/ . /*another*/ expr;\n}")
+    def expr = file.classes[0].fields[0].initializer
+    assert expr != null
+    runCommand { expr.firstChild.delete() }
+    assert expr.text == "expr"
+  }
+
   private PsiJavaFile configureFile(String text) {
     myFixture.configureByText("a.java", text) as PsiJavaFile
   }