Extract parts of XpectRunner singleton

This change extracts parts of the singleton XpectRunner
to another class, so that other implementations can set the values of the singleton.

This change is required, in order to provide alternatives of XpectRunner,
such as a JUnit 5 alternative, without depending on XpectRunner.

Preparation for: eclipse#262

org.eclipse.xpect.ui/src/org/eclipse/xpect/ui/util/XpectFileAccess.java

@@ -30,6 +30,7 @@
 import org.eclipse.xpect.XpectFile;
 import org.eclipse.xpect.registry.ILanguageInfo;
 import org.eclipse.xpect.runner.XpectRunner;
+import org.eclipse.xpect.runner.XpectTestGlobalState;
 
 import com.google.inject.Injector;
 
@@ -67,8 +68,8 @@ protected static ResourceSet cloneResourceSet(ResourceSet rs) {
 		// need delegation or nothing because of "java" protocol
 		// result.setResourceFactoryRegistry(rs.getResourceFactoryRegistry());
 		result.setURIConverter(rs.getURIConverter());
-		if (XpectRunner.testClassloader != null) {
-			result.setClasspathURIContext(XpectRunner.testClassloader);
+		if (XpectTestGlobalState.INSTANCE.testClass() != null) {
+			result.setClasspathURIContext(XpectTestGlobalState.INSTANCE.testClass().getClassLoader());
 			result.setClasspathUriResolver(new ClassloaderClasspathUriResolver());
 		} else if (rs instanceof XtextResourceSet) {
 			XtextResourceSet xrs = (XtextResourceSet) rs;

org.eclipse.xpect.ui/src/org/eclipse/xpect/ui/util/XpectUtil.java

@@ -28,6 +28,7 @@
 import org.eclipse.xpect.XpectFile;
 import org.eclipse.xpect.XpectJavaModel;
 import org.eclipse.xpect.runner.XpectRunner;
+import org.eclipse.xpect.runner.XpectTestGlobalState;
 import org.eclipse.xpect.ui.internal.XpectActivator;
 
 import com.google.inject.Injector;
@@ -40,8 +41,8 @@ public static XpectFile loadFile(IFile file) {
 		Injector injector = XpectActivator.getInstance().getInjector(XpectActivator.ORG_ECLIPSE_XPECT_XPECT);
 		XtextResourceSet rs = new XtextResourceSet();
 		IJavaProject javaProject = JavaCore.create(file.getProject());
-		if (XpectRunner.testClassloader != null) {
-			rs.setClasspathURIContext(XpectRunner.testClassloader);
+		if (XpectTestGlobalState.INSTANCE.testClass() != null) {
+			rs.setClasspathURIContext(XpectTestGlobalState.INSTANCE.testClass().getClassLoader());
 			rs.setClasspathUriResolver(new ClassloaderClasspathUriResolver());
 		} else if (javaProject != null && javaProject.exists()) {
 			rs.setClasspathURIContext(javaProject);

org.eclipse.xpect/src/org/eclipse/xpect/runner/XpectRunner.java

@@ -72,6 +72,12 @@ public XpectRunner(Class<?> testClass) throws InitializationError {
 		this.uriProvider = findUriProvider(testClass);
 		this.xpectInjector = findXpectInjector();
 		this.xpectJavaModel = XpectJavaModelManager.createJavaModel(testClass);
+		/*
+		 * NOTE:
+		 * Do this before the state creation, otherwise the parts that depend on
+		 * the singleton won't initialize properly and tests will fail to run!
+		 */
+		XpectTestGlobalState.INSTANCE.set(xpectJavaModel, testClass);
 		this.state = TestExecutor.createState(createRootConfiguration());
 	}
 

org.eclipse.xpect/src/org/eclipse/xpect/runner/XpectTestGlobalState.java

@@ -0,0 +1,38 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Simeon Andreev and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Simeon Andreev - Initial contribution and API
+ *******************************************************************************/
+package org.eclipse.xpect.runner;
+
+import org.eclipse.xpect.XpectJavaModel;
+
+/**
+ * @author Simeon Andreev - Initial contribution and API
+ */
+public class XpectTestGlobalState {
+
+	public static final XpectTestGlobalState INSTANCE = new XpectTestGlobalState();
+
+	private XpectJavaModel model;
+	private Class<?> testClass;
+
+	public void set(XpectJavaModel model, Class<?> testClass) {
+		this.model = model;
+		this.testClass = testClass;
+	}
+
+	public XpectJavaModel model() {
+		return model;
+	}
+
+	public Class<?> testClass() {
+		return testClass;
+	}
+}

org.eclipse.xpect/src/org/eclipse/xpect/services/XtResourceServiceProviderProvider.java

@@ -17,6 +17,7 @@
 import org.eclipse.xpect.XpectConstants;
 import org.eclipse.xpect.registry.ILanguageInfo;
 import org.eclipse.xpect.runner.XpectRunner;
+import org.eclipse.xpect.runner.XpectTestGlobalState;
 import org.eclipse.xpect.util.IXtInjectorProvider;
 
 import com.google.inject.Injector;
@@ -32,8 +33,8 @@ private XtResourceServiceProviderProvider() {
 	}
 
 	public IResourceServiceProvider get(URI uri, String contentType) {
-		if (XpectRunner.INSTANCE != null) {
-			Injector injector = IXtInjectorProvider.INSTANCE.getInjector(XpectRunner.INSTANCE.getXpectJavaModel(), uri);
+		if (XpectTestGlobalState.INSTANCE.model() != null) {
+			Injector injector = IXtInjectorProvider.INSTANCE.getInjector(XpectTestGlobalState.INSTANCE.model(), uri);
 			if (injector != null)
 				return injector.getInstance(IResourceServiceProvider.class);
 		}

org.eclipse.xpect/src/org/eclipse/xpect/util/ClasspathUtil.java

@@ -26,6 +26,7 @@
 
 import org.apache.log4j.Logger;
 import org.eclipse.xpect.runner.XpectRunner;
+import org.eclipse.xpect.runner.XpectTestGlobalState;
 
 import com.google.common.base.Joiner;
 import com.google.common.collect.Sets;
@@ -81,8 +82,8 @@ public static Collection<URL> findResources(String... fileNames) {
 			}
 		}
 		// for some reason, ucl.getURLs() doesn't catch the current project in standalone maven surefire
-		if (XpectRunner.INSTANCE != null) {
-			Class<?> clazz = XpectRunner.INSTANCE.getTestClass().getJavaClass();
+		if (XpectTestGlobalState.INSTANCE.testClass() != null) {
+			Class<?> clazz = XpectTestGlobalState.INSTANCE.testClass();
 			String[] segments = clazz.getName().split("\\.");
 			String fileName = Joiner.on('/').join(segments) + ".class";
 			URL resource = clazz.getClassLoader().getResource(fileName);

org.eclipse.xpect/src/org/eclipse/xpect/util/EnvironmentUtil.java

@@ -14,15 +14,15 @@
 
 import org.eclipse.emf.ecore.plugin.EcorePlugin;
 import org.eclipse.xpect.Environment;
-import org.eclipse.xpect.runner.XpectRunner;
+import org.eclipse.xpect.runner.XpectTestGlobalState;
 
 import com.google.common.base.Joiner;
 
 public class EnvironmentUtil {
 	public static final Environment ENVIRONMENT = detectEnvironement();
 
 	private static Environment detectEnvironement() {
-		if (XpectRunner.testClassloader != null) {
+		if (XpectTestGlobalState.INSTANCE.testClass() != null) {
 			if (EcorePlugin.IS_ECLIPSE_RUNNING)
 				return Environment.PLUGIN_TEST;
 			else