refactor(MTEExtension): use Engines instead of broad Helper class

src/main/java/org/terasology/moduletestingenvironment/Engines.java

@@ -147,7 +147,7 @@ public List<TerasologyEngine> getEngines() {
     /**
      * Get the host context for this module testing environment.
      * <p>
-     * The host context will be null if the testing environment has not been set up via {@link ModuleTestingHelper#setup()}
+     * The host context will be null if the testing environment has not been set up via {@link #setup()}
      * beforehand.
      *
      * @return the engine's host context, or null if not set up yet

src/main/java/org/terasology/moduletestingenvironment/MTEExtension.java

@@ -64,44 +64,44 @@ public void beforeAll(ExtensionContext context) {
     @Override
     public boolean supportsParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
         Class<?> type = parameterContext.getParameter().getType();
-        ModuleTestingHelper helper = getHelper(extensionContext);
-        return helper.getHostContext().get(type) != null
+        Engines engines = getEngines(extensionContext);
+        return engines.getHostContext().get(type) != null
                 || type.isAssignableFrom(Engines.class)
                 || type.isAssignableFrom(MainLoop.class)
                 || type.isAssignableFrom(ModuleTestingHelper.class);
     }
 
     @Override
     public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
-        ModuleTestingHelper helper = getHelper(extensionContext);
+        Engines engines = getEngines(extensionContext);
         Class<?> type = parameterContext.getParameter().getType();
 
-        return getDIInstance(helper, type);
+        return getDIInstance(engines, type);
     }
 
-    private Object getDIInstance(ModuleTestingHelper helper, Class<?> type) {
+    private Object getDIInstance(Engines engines, Class<?> type) {
         if (type.isAssignableFrom(Engines.class)) {
-            return helper.engines;
+            return engines;
         } else if (type.isAssignableFrom(MainLoop.class)) {
-            return helper.mainLoop;
+            return new MainLoop(engines);
         } else if (type.isAssignableFrom(ModuleTestingHelper.class)) {
-            return helper;
+            return new ModuleTestingHelper(engines);
         } else {
-            return helper.getHostContext().get(type);
+            return engines.getHostContext().get(type);
         }
     }
 
     @Override
     public void postProcessTestInstance(Object testInstance, ExtensionContext extensionContext) {
-        ModuleTestingHelper helper = getHelper(extensionContext);
+        Engines engines = getEngines(extensionContext);
         List<IllegalAccessException> exceptionList = new LinkedList<>();
         Class<?> type = testInstance.getClass();
         while (type != null) {
             Arrays.stream(type.getDeclaredFields())
                     .filter((field) -> field.getAnnotation(In.class) != null)
                     .peek((field) -> field.setAccessible(true))
                     .forEach((field) -> {
-                        Object candidateObject = getDIInstance(helper, field.getType());
+                        Object candidateObject = getDIInstance(engines, field.getType());
                         try {
                             field.set(testInstance, candidateObject);
                         } catch (IllegalAccessException e) {
@@ -128,9 +128,9 @@ public Set<String> getDependencyNames(ExtensionContext context) {
     }
 
     /**
-     * Get the ModuleTestingHelper for this test.
+     * Get the Engines for this test.
      * <p>
-     * The new ModuleTestingHelper instance is configured using the {@link Dependencies} and {@link UseWorldGenerator}
+     * The new Engines instance is configured using the {@link Dependencies} and {@link UseWorldGenerator}
      * annotations for the test class.
      * <p>
      * This will create a new instance when necessary. It will be stored in the
@@ -140,12 +140,12 @@ public Set<String> getDependencyNames(ExtensionContext context) {
      * @param context for the current test
      * @return configured for this test
      */
-    protected ModuleTestingHelper getHelper(ExtensionContext context) {
+    protected Engines getEngines(ExtensionContext context) {
         ExtensionContext.Store store = context.getStore(helperLifecycle.apply(context));
-        HelperCleaner autoCleaner = store.getOrComputeIfAbsent(
-                HelperCleaner.class, k -> new HelperCleaner(getDependencyNames(context), getWorldGeneratorUri(context)),
-                HelperCleaner.class);
-        return autoCleaner.helper;
+        EnginesCleaner autoCleaner = store.getOrComputeIfAbsent(
+                EnginesCleaner.class, k -> new EnginesCleaner(getDependencyNames(context), getWorldGeneratorUri(context)),
+                EnginesCleaner.class);
+        return autoCleaner.engines;
     }
 
     /**
@@ -184,23 +184,23 @@ void setupLogging() {
     }
 
     /**
-     * Manages a ModuleTestingHelper for storage in an ExtensionContext.
+     * Manages Engines for storage in an ExtensionContext.
      * <p>
      * Implements {@link ExtensionContext.Store.CloseableResource CloseableResource} to dispose of
-     * the {@link ModuleTestingHelper} when the context is closed.
+     * the {@link Engines} when the context is closed.
      */
-    static class HelperCleaner implements ExtensionContext.Store.CloseableResource {
-        protected ModuleTestingHelper helper;
+    static class EnginesCleaner implements ExtensionContext.Store.CloseableResource {
+        protected Engines engines;
 
-        HelperCleaner(Set<String> dependencyNames, String worldGeneratorUri) {
-            helper = new ModuleTestingHelper(dependencyNames, worldGeneratorUri);
-            helper.setup();
+        EnginesCleaner(Set<String> dependencyNames, String worldGeneratorUri) {
+            engines = new Engines(dependencyNames, worldGeneratorUri);
+            engines.setup();
         }
 
         @Override
         public void close() {
-            helper.tearDown();
-            helper = null;
+            engines.tearDown();
+            engines = null;
         }
     }
 }

src/main/java/org/terasology/moduletestingenvironment/ModuleTestingEnvironment.java

@@ -90,7 +90,7 @@ public interface ModuleTestingEnvironment {
     /**
      * Get the host context for this module testing environment.
      * <p>
-     * The host context will be null if the testing environment has not been set up via {@link ModuleTestingHelper#setup()}
+     * The host context will be null if the testing environment has not been set up via {@link Engines#setup()}
      * beforehand.
      *
      * @return the engine's host context, or null if not set up yet

src/main/java/org/terasology/moduletestingenvironment/ModuleTestingHelper.java

@@ -13,7 +13,6 @@
 
 import java.io.IOException;
 import java.util.List;
-import java.util.Set;
 import java.util.function.Supplier;
 
 /**
@@ -82,27 +81,9 @@ public class ModuleTestingHelper implements ModuleTestingEnvironment {
     final Engines engines;
     final MainLoop mainLoop;
 
-    protected ModuleTestingHelper(Set<String> dependencies, String worldGeneratorUri) {
-        engines = new Engines(dependencies, worldGeneratorUri);
-        mainLoop = new MainLoop(engines);
-    }
-
-    /**
-     * Set up and start the engine as configured via this environment.
-     * <p>
-     * Every instance should be shut down properly by calling {@link #tearDown()}.
-     */
-    protected void setup() {
-        engines.setup();
-    }
-
-    /**
-     * Shut down a previously started testing environment.
-     * <p>
-     * Used to properly shut down and clean up a testing environment set up and started with {@link #setup()}.
-     */
-    protected void tearDown() {
-        engines.tearDown();
+    ModuleTestingHelper(Engines engines) {
+        this.engines = engines;
+        this.mainLoop = new MainLoop(engines);
     }
 
     @Override