Added test case

Author: drpayyne

src/com/magento/idea/magento2plugin/reference/provider/EventNameReferenceProvider.java

@@ -28,39 +28,49 @@ public class EventNameReferenceProvider  extends PsiReferenceProvider {
 
     @NotNull
     @Override
-    public PsiReference[] getReferencesByElement(@NotNull PsiElement element, @NotNull ProcessingContext context) {
-        String value = StringUtil.unquoteString(element.getText());
-        Collection<VirtualFile> containingFiles = FileBasedIndex.getInstance()
+    public PsiReference[] getReferencesByElement(
+            @NotNull final PsiElement element,
+            @NotNull final ProcessingContext context
+    ) {
+        final String value = StringUtil.unquoteString(element.getText());
+        final List<PsiReference> psiReferences = new ArrayList<>();
+        final Collection<VirtualFile> containingFiles = FileBasedIndex.getInstance()
             .getContainingFiles(EventNameIndex.KEY, value,
                     GlobalSearchScope.getScopeRestrictedByFileTypes(
                             GlobalSearchScope.allScope(element.getProject()),
                             PhpFileType.INSTANCE
                     )
             );
 
-        PsiManager psiManager = PsiManager.getInstance(element.getProject());
-        for (VirtualFile virtualFile: containingFiles) {
-            PhpFile phpFile = (PhpFile) psiManager.findFile(virtualFile);
+        final PsiManager psiManager = PsiManager.getInstance(element.getProject());
+        final List<PsiElement> psiElements = new ArrayList<>();
+        for (final VirtualFile virtualFile: containingFiles) {
+            final PhpFile phpFile = (PhpFile) psiManager.findFile(virtualFile);
             if (phpFile != null) {
-                List<PsiElement> psiElements = new ArrayList<>();
                 recursiveFill(psiElements, phpFile, value);
-                if (psiElements.size() > 0) {
-                    return new PsiReference[] {new PolyVariantReferenceBase(element, psiElements)};
+                if (!psiElements.isEmpty()) {
+                    psiReferences.add(new PolyVariantReferenceBase(element, psiElements));
+                    break;
                 }
             }
         }
-        return PsiReference.EMPTY_ARRAY;
+
+        return psiReferences.toArray(new PsiReference[0]);
     }
 
-    private void recursiveFill(List<PsiElement> psiElements, PsiElement psiElement, String typeName) {
+    private void recursiveFill(
+            final List<PsiElement> psiElements,
+            final PsiElement psiElement,
+            final String typeName
+    ) {
         if (PhpPatternsHelper.STRING_METHOD_ARGUMENT.accepts(psiElement)) {
             if (StringUtil.unquoteString(psiElement.getText()).equals(typeName)) {
                 psiElements.add(psiElement);
             }
             return;
         }
 
-        for (PsiElement child: psiElement.getChildren()) {
+        for (final PsiElement child: psiElement.getChildren()) {
             recursiveFill(psiElements, child, typeName);
         }
     }

testData/reference/xml/ObserverReferenceRegistrar/eventNameMustNotHaveReference/events.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
+    <event name="invalid_event<caret>">
+        <observer name="test_observer" instance="Magento\Catalog\Observer\TestObserver" />
+    </event>
+</config>

tests/com/magento/idea/magento2plugin/reference/BaseReferenceTestCase.java

@@ -23,6 +23,9 @@
 import com.magento.idea.magento2plugin.reference.xml.PolyVariantReferenceBase;
 import org.jetbrains.annotations.Nullable;
 
+@SuppressWarnings({
+        "PMD.TooManyMethods",
+})
 public abstract class BaseReferenceTestCase extends BaseInspectionsTestCase {
     private static final String testDataFolderPath = "testData" + File.separator//NOPMD
             + "reference" + File.separator;

tests/com/magento/idea/magento2plugin/reference/xml/ObserverReferenceRegistrarTest.java

@@ -10,7 +10,7 @@
 public class ObserverReferenceRegistrarTest extends ReferenceXmlFixtureTestCase {
 
     /**
-     * Tests for observer instance reference in events.xml
+     * Tests for observer instance reference in events.xml.
      */
     public void testObserverInstanceMustHaveReference() {
         myFixture.configureByFile(this.getFixturePath(ModuleEventsXml.FILE_NAME));
@@ -19,11 +19,20 @@ public void testObserverInstanceMustHaveReference() {
     }
 
     /**
-     * Tests for event name reference in events.xml
+     * Tests for event name reference in events.xml.
      */
     public void testEventNameMustHaveReference() {
         myFixture.configureByFile(this.getFixturePath(ModuleEventsXml.FILE_NAME));
 
         assertHasReferenceToMethodArgument("test_event_in_block");
     }
+
+    /**
+     * Tests for no event name reference in events.xml.
+     */
+    public void testEventNameMustNotHaveReference() {
+        myFixture.configureByFile(this.getFixturePath(ModuleEventsXml.FILE_NAME));
+
+        assertEmptyReference();
+    }
 }