Add tests for Runner and Backend suppliers

core/src/main/java/cucumber/api/cli/Main.java

@@ -18,8 +18,6 @@
 import cucumber.runtime.io.ResourceLoaderClassFinder;
 import cucumber.runtime.model.FeatureLoader;
 
-import java.util.ArrayList;
-
 import static java.util.Arrays.asList;
 
 public class Main {
@@ -37,7 +35,7 @@ public static void main(String[] argv) {
      * @return 0 if execution was successful, 1 if it was not (test failures)
      */
     public static byte run(String[] argv, ClassLoader classLoader) {
-        RuntimeOptions runtimeOptions = new RuntimeOptions(new ArrayList<String>(asList(argv)));
+        RuntimeOptions runtimeOptions = new RuntimeOptions(asList(argv));
 
         ResourceLoader resourceLoader = new MultiLoader(classLoader);
         ClassFinder classFinder = new ResourceLoaderClassFinder(resourceLoader, classLoader);

core/src/main/java/cucumber/runtime/RunnerSupplier.java

@@ -14,7 +14,12 @@ public class RunnerSupplier implements Supplier<Runner> {
 
     private final ThreadLocal<Runner> runners = new ThreadLocal<Runner>();
 
-    public RunnerSupplier(RuntimeOptions runtimeOptions, EventBus eventBus, Supplier<Collection<? extends Backend>> backendSupplier, Supplier<Glue> glueSupplier) {
+    public RunnerSupplier(
+        RuntimeOptions runtimeOptions,
+        EventBus eventBus,
+        Supplier<Collection<? extends Backend>> backendSupplier,
+        Supplier<Glue> glueSupplier
+    ) {
         this.backendSupplier = backendSupplier;
         this.runtimeOptions = runtimeOptions;
         this.glueSupplier = glueSupplier;

core/src/test/java/cucumber/runtime/BackendSupplierTest.java

@@ -0,0 +1,33 @@
+package cucumber.runtime;
+
+import cucumber.runtime.io.MultiLoader;
+import cucumber.runtime.io.ResourceLoader;
+import cucumber.runtime.io.ResourceLoaderClassFinder;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collections;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
+public class BackendSupplierTest {
+
+    private BackendSupplier backendSupplier;
+
+    @Before
+    public void before() {
+        ClassLoader classLoader = getClass().getClassLoader();
+        RuntimeOptions runtimeOptions = new RuntimeOptions(Collections.<String>emptyList());
+        ResourceLoader resourceLoader = new MultiLoader(classLoader);
+        ClassFinder classFinder = new ResourceLoaderClassFinder(resourceLoader, classLoader);
+        this.backendSupplier = new BackendSupplier(resourceLoader, classFinder, runtimeOptions);
+    }
+
+    @Test
+    public void should_create_a_backend() {
+        assertThat(backendSupplier.get().iterator().next(), is(notNullValue()));
+    }
+
+}

core/src/test/java/cucumber/runtime/RunnerSupplierTest.java

@@ -0,0 +1,75 @@
+package cucumber.runtime;
+
+
+import cucumber.runner.EventBus;
+import cucumber.runner.Runner;
+import cucumber.runner.TimeService;
+import cucumber.runtime.io.MultiLoader;
+import cucumber.runtime.io.ResourceLoader;
+import cucumber.runtime.io.ResourceLoaderClassFinder;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collections;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThat;
+
+
+public class RunnerSupplierTest {
+
+    private RunnerSupplier runnerSupplier;
+
+    @Before
+    public void before() {
+        ClassLoader classLoader = getClass().getClassLoader();
+        RuntimeOptions runtimeOptions = new RuntimeOptions(Collections.<String>emptyList());
+        ResourceLoader resourceLoader = new MultiLoader(classLoader);
+        ClassFinder classFinder = new ResourceLoaderClassFinder(resourceLoader, classLoader);
+        BackendSupplier backendSupplier = new BackendSupplier(resourceLoader, classFinder, runtimeOptions);
+        EventBus eventBus = new EventBus(TimeService.SYSTEM);
+        RuntimeGlueSupplier glueSupplier = new RuntimeGlueSupplier();
+        runnerSupplier = new RunnerSupplier(runtimeOptions, eventBus, backendSupplier, glueSupplier);
+    }
+
+
+    @Test
+    public void should_create_a_runner() {
+        assertThat(runnerSupplier.get(), is(notNullValue()));
+    }
+
+    @Test
+    public void should_create_a_runner_per_thread() throws InterruptedException {
+        final Runner[] runners = new Runner[2];
+        Thread thread0 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                runners[0] = runnerSupplier.get();
+            }
+        });
+
+        Thread thread1 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                runners[1] = runnerSupplier.get();
+            }
+        });
+
+        thread0.start();
+        thread1.start();
+
+        thread0.join();
+        thread1.join();
+
+        assertNotSame(runners[0], runners[1]);
+    }
+
+    @Test
+    public void should_return_the_same_runner_on_subsequent_calls() {
+        assertSame(runnerSupplier.get(), runnerSupplier.get());
+    }
+
+}

core/src/test/java/cucumber/runtime/StubBackend.java

@@ -0,0 +1,36 @@
+package cucumber.runtime;
+
+import cucumber.runtime.io.ResourceLoader;
+import cucumber.runtime.snippets.FunctionNameGenerator;
+import gherkin.pickles.PickleStep;
+import io.cucumber.stepexpression.TypeRegistry;
+
+import java.util.List;
+
+public class StubBackend implements Backend {
+
+    @SuppressWarnings("unused") // reflection to create backend
+    public StubBackend(ResourceLoader resourceLoader, TypeRegistry typeRegistry) {
+
+    }
+
+    @Override
+    public void loadGlue(Glue glue, List<String> gluePaths) {
+
+    }
+
+    @Override
+    public void buildWorld() {
+
+    }
+
+    @Override
+    public void disposeWorld() {
+
+    }
+
+    @Override
+    public String getSnippet(PickleStep step, String keyword, FunctionNameGenerator functionNameGenerator) {
+        return null;
+    }
+}