984: Filtered generated folder from reference resolving results

resources/META-INF/plugin.xml

@@ -617,5 +617,7 @@
         <frameworkProjectConfigurableProvider implementation="com.magento.idea.magento2plugin.project.ConfigurableProvider"/>
         <frameworkUsageProvider implementation="com.magento.idea.magento2plugin.project.UsagesProvider"/>
         <libraryRoot id="phpstorm.meta.php" path="/.phpstorm.meta.php/" runtime="false"/>
+
+        <referenceResolver2 implementation="com.magento.idea.magento2plugin.lang.php.MagentoProxyDeclarationFilter" order="first"/>
     </extensions>
 </idea-plugin>

src/com/magento/idea/magento2plugin/lang/php/MagentoProxyDeclarationFilter.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+package com.magento.idea.magento2plugin.lang.php;
+
+import com.intellij.openapi.util.registry.Registry;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.util.containers.ContainerUtil;
+import com.jetbrains.php.lang.psi.PhpMultipleDeclarationFilter;
+import com.jetbrains.php.lang.psi.elements.PhpNamedElement;
+import com.magento.idea.magento2plugin.project.Settings;
+import java.util.Collection;
+import org.jetbrains.annotations.NotNull;
+
+public class MagentoProxyDeclarationFilter implements PhpMultipleDeclarationFilter {
+
+    @SuppressWarnings({"PMD.CognitiveComplexity", "PMD.ConfusingTernary"})
+    @Override
+    public <E extends PhpNamedElement> Collection<E> filter(
+            final @NotNull PsiElement psiElement,
+            final Collection<E> candidates
+    ) {
+        if (!Settings.isEnabled(psiElement.getProject())) {
+            return candidates;
+        } else if (!Registry.is("php.use.multiproject.ref.resolver", true)) {
+            return candidates;
+        } else if (candidates.size() == 1) { // NOPMD
+            return candidates;
+        } else if (psiElement.getContainingFile() == null) {
+            return candidates;
+        }
+
+        return ContainerUtil.filter(candidates,
+                (candidate) -> {
+                    final PsiFile file = candidate.getContainingFile();
+
+                    if (file == null) {
+                        return false;
+                    }
+                    final VirtualFile virtualFile = file.getVirtualFile();
+
+                    if (virtualFile == null) {
+                        return false;
+                    }
+
+                    return !virtualFile.getPath().contains("/generated/");
+                });
+    }
+}