Allow invoking code completion actions on invisible editor in headless environment

platform/lang-impl/src/com/intellij/codeInsight/completion/actions/BaseCodeCompletionAction.java

-/*
- * Copyright 2000-2013 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2019 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.codeInsight.completion.actions;
 
 import com.intellij.codeInsight.completion.CodeCompletionHandlerBase;
@@ -68,7 +54,7 @@ public abstract class BaseCodeCompletionAction extends DumbAwareAction implement
     PsiFile psiFile = project == null ? null : PsiUtilBase.getPsiFileInEditor(editor, project);
     if (psiFile == null) return;
 
-    if (!ApplicationManager.getApplication().isUnitTestMode() && !editor.getContentComponent().isShowing()) return;
+    if (!ApplicationManager.getApplication().isHeadlessEnvironment() && !editor.getContentComponent().isShowing()) return;
     e.getPresentation().setEnabled(true);
   }
 }