Adds JellyReferenceContributor to link Jelly files to Java code

README.md

@@ -20,6 +20,7 @@
 * Navigation from the Jelly tags to their definitions
   * Integrate `st:documentation` tag into IntelliJ documentation support
   * Report custom tag attributes that are marked deprecated in `st:documentation`.
+* Navigation from Jelly attribute `field` in `entry` tags to their Java definition
 * Error checks and autocompletion on attributes and elements of taglibs
 * `style` attribute and `script` tag contents should be recognized as CSS and JavaScript correspondingly.
 * [Jenkins Symbols](https://weekly.ci.jenkins.io/design-library/symbols/) suggestions are available when using `<l:icon src="..." />`

src/main/java/io/jenkins/stapler/idea/jelly/JellyJavaReferenceProvider.java

@@ -0,0 +1,29 @@
+package io.jenkins.stapler.idea.jelly;
+
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiReference;
+import com.intellij.psi.PsiReferenceProvider;
+import com.intellij.psi.xml.XmlAttribute;
+import com.intellij.psi.xml.XmlAttributeValue;
+import com.intellij.util.ProcessingContext;
+import org.jetbrains.annotations.NotNull;
+
+public class JellyJavaReferenceProvider extends PsiReferenceProvider {
+
+    @Override
+    public PsiReference @NotNull [] getReferencesByElement(
+            @NotNull PsiElement element, @NotNull ProcessingContext context) {
+
+        if (!(element instanceof XmlAttributeValue attributeValue)) {
+            return PsiReference.EMPTY_ARRAY;
+        }
+        if (attributeValue.getParent() instanceof final XmlAttribute attribute) {
+            if (attribute.getParent().getLocalName().equals("entry")
+                    && attribute.getLocalName().equals("field")) {
+                return new PsiReference[] {new JellyToJavaClassReference(attributeValue)};
+            }
+        }
+
+        return PsiReference.EMPTY_ARRAY;
+    }
+}

src/main/java/io/jenkins/stapler/idea/jelly/JellyReferenceContributor.java

@@ -0,0 +1,13 @@
+package io.jenkins.stapler.idea.jelly;
+
+import com.intellij.patterns.XmlPatterns;
+import com.intellij.psi.PsiReferenceContributor;
+import com.intellij.psi.PsiReferenceRegistrar;
+
+public class JellyReferenceContributor extends PsiReferenceContributor {
+
+    @Override
+    public void registerReferenceProviders(PsiReferenceRegistrar registrar) {
+        registrar.registerReferenceProvider(XmlPatterns.xmlAttributeValue(), new JellyJavaReferenceProvider());
+    }
+}

src/main/java/io/jenkins/stapler/idea/jelly/JellyToJavaClassReference.java

@@ -0,0 +1,56 @@
+package io.jenkins.stapler.idea.jelly;
+
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.PsiReferenceBase;
+import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.search.PsiShortNamesCache;
+import com.intellij.psi.util.PropertyUtilBase;
+import com.intellij.psi.xml.XmlAttributeValue;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class JellyToJavaClassReference extends PsiReferenceBase<XmlAttributeValue> {
+
+    public JellyToJavaClassReference(@NotNull XmlAttributeValue element) {
+        super(element, true);
+    }
+
+    @Override
+    public @Nullable PsiElement resolve() {
+
+        final var containingFile = getElement().getContainingFile();
+        final var containingDirectory = containingFile.getContainingDirectory();
+
+        String className = containingDirectory.getName();
+        String methodName = getElement().getValue();
+        Project project = getElement().getProject();
+
+        PsiShortNamesCache cache = PsiShortNamesCache.getInstance(project);
+        GlobalSearchScope scope = GlobalSearchScope.projectScope(project);
+
+        String[] getterNames = PropertyUtilBase.suggestGetterNames(methodName);
+
+        PsiClass[] psiClass = cache.getClassesByName(className, scope);
+        for (var aClass : psiClass) {
+            for (var getterName : getterNames) {
+                for (PsiMethod method : aClass.findMethodsByName(getterName, true)) {
+                    return method;
+                }
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public boolean isReferenceTo(@NotNull PsiElement element) {
+        return super.isReferenceTo(element);
+    }
+
+    @Override
+    public Object @NotNull [] getVariants() {
+        return EMPTY_ARRAY;
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -9,6 +9,10 @@
 <!--  <idea-version since-build="110.00"/>-->
 
   <extensions defaultExtensionNs="com.intellij">
+
+    <psi.referenceContributor language="Jelly" implementation="io.jenkins.stapler.idea.jelly.JellyReferenceContributor"/>
+
+
     <!--
       REFERENCE:
       to find out how to register a given extension point,

src/test/java/io/jenkins/stapler/idea/jelly/JellyReferenceContributorTest.java

@@ -0,0 +1,39 @@
+package io.jenkins.stapler.idea.jelly;
+
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.PsiReference;
+import com.intellij.testFramework.fixtures.BasePlatformTestCase;
+
+public class JellyReferenceContributorTest extends BasePlatformTestCase {
+
+    @Override
+    protected String getTestDataPath() {
+        return "src/test/testData";
+    }
+
+    public void testReferenceAtCaret() {
+        myFixture.configureByText(
+                "Foo.java",
+                """
+                public class Foo {
+                    public String getBar() {
+                        return "";
+                    }
+                }
+                """);
+
+        myFixture.configureByFiles("Foo/config.jelly");
+
+        PsiReference reference = myFixture.getReferenceAtCaretPosition();
+        assertNotNull(reference);
+
+        PsiElement resolved = reference.resolve();
+        assertNotNull(resolved);
+        if (resolved instanceof PsiMethod method) {
+            assertEquals("getBar", method.getName());
+        } else {
+            fail("not a method");
+        }
+    }
+}

src/test/testData/Foo/config.jelly

@@ -0,0 +1,6 @@
+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
+  <f:entry field="b<caret>ar">
+       <f:textbox/>
+  </f:entry>
+</j:jelly>