[java] RemoteWebDriver should fail fast if there is no command executor provided

Author: barancev

java/client/src/org/openqa/selenium/remote/RemoteWebDriver.java

@@ -83,9 +83,9 @@
 import org.openqa.selenium.virtualauthenticator.VirtualAuthenticatorOptions;
 
 @Augmentable
-public class RemoteWebDriver implements WebDriver, JavascriptExecutor,
-      HasInputDevices, HasCapabilities, Interactive, TakesScreenshot,
-      HasVirtualAuthenticator {
+public class RemoteWebDriver implements WebDriver, JavascriptExecutor, HasInputDevices,
+                                        HasCapabilities, Interactive, TakesScreenshot,
+                                        HasVirtualAuthenticator {
 
   // TODO(dawagner): This static logger should be unified with the per-instance localLogs
   private static final Logger logger = Logger.getLogger(RemoteWebDriver.class.getName());
@@ -114,13 +114,20 @@ public RemoteWebDriver(Capabilities capabilities) {
     this((URL) null, capabilities);
   }
 
+  public RemoteWebDriver(URL remoteAddress, Capabilities capabilities) {
+    this(new HttpCommandExecutor(remoteAddress), capabilities);
+  }
+
   public RemoteWebDriver(CommandExecutor executor, Capabilities capabilities) {
+    if (executor == null) {
+      throw new IllegalArgumentException("RemoteWebDriver cannot work without a command executor");
+    }
     this.executor = executor;
 
     init(capabilities);
 
     if (executor instanceof NeedsLocalLogs) {
-      ((NeedsLocalLogs)executor).setLocalLogs(localLogs);
+      ((NeedsLocalLogs) executor).setLocalLogs(localLogs);
     }
 
     try {
@@ -136,10 +143,6 @@ public RemoteWebDriver(CommandExecutor executor, Capabilities capabilities) {
     }
   }
 
-  public RemoteWebDriver(URL remoteAddress, Capabilities capabilities) {
-    this(new HttpCommandExecutor(remoteAddress), capabilities);
-  }
-
   @Beta
   public static RemoteWebDriverBuilder builder() {
     return new RemoteWebDriverBuilder();
@@ -173,8 +176,8 @@ private void init(Capabilities capabilities) {
     Set<String> logTypesToInclude = builder.build();
 
     LocalLogs performanceLogger = LocalLogs.getStoringLoggerInstance(logTypesToInclude);
-    LocalLogs clientLogs = LocalLogs.getHandlerBasedLoggerInstance(LoggingHandler.getInstance(),
-        logTypesToInclude);
+    LocalLogs clientLogs = LocalLogs.getHandlerBasedLoggerInstance(
+      LoggingHandler.getInstance(), logTypesToInclude);
     localLogs = LocalLogs.getCombinedLogsHolder(clientLogs, performanceLogger);
     remoteLogs = new RemoteLogs(executeMethod, localLogs);
   }

java/client/test/org/openqa/selenium/remote/RemoteWebDriverUnitTest.java

@@ -71,19 +71,20 @@ public class RemoteWebDriverUnitTest {
   private static final String ELEMENT_KEY = "element-6066-11e4-a52e-4f735466cecf";
 
   @Test
-  public void whatIfExecutorIsNull() {
-    assertThatExceptionOfType(UnreachableBrowserException.class)
-        .isThrownBy(() -> new RemoteWebDriver((CommandExecutor) null, new ImmutableCapabilities()));
+  public void constructorShouldThrowIfExecutorIsNull() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+      .isThrownBy(() -> new RemoteWebDriver((CommandExecutor) null, new ImmutableCapabilities()))
+      .withMessage("RemoteWebDriver cannot work without a command executor");
   }
 
   @Test
-  public void whatIfExecutorCannotStartASession() throws IOException {
+  public void constructorShouldThrowIfExecutorCannotStartASession() throws IOException {
     CommandExecutor executor = prepareExecutorMock(nullResponder, nullResponder);
     assertThatExceptionOfType(UnreachableBrowserException.class)
-        .isThrownBy(() -> new RemoteWebDriver(executor, new ImmutableCapabilities()));
+      .isThrownBy(() -> new RemoteWebDriver(executor, new ImmutableCapabilities()));
 
     verify(executor).execute(argThat(
-        command -> command.getName().equals(DriverCommand.NEW_SESSION)));
+      command -> command.getName().equals(DriverCommand.NEW_SESSION)));
     verifyNoMoreInteractions(executor);
   }
 
@@ -1166,8 +1167,9 @@ private Function<Command, Response> valueResponder(Object value) {
   }
 
   @SafeVarargs
-  private final CommandExecutor prepareExecutorMock(
-      Function<Command, Response>... handlers) throws IOException {
+  private final CommandExecutor prepareExecutorMock(Function<Command, Response>... handlers)
+    throws IOException
+  {
     CommandExecutor executor = mock(CommandExecutor.class);
     OngoingStubbing<Response> callChain = when(executor.execute(any()));
     for (Function<Command, Response> handler : handlers) {