Improve PipelineOptionsFactoryTest

Currently the test uses the literal string for the default runner and
available runners. Instead, refer to the default runner class and
extract the simple name from that class.

Automatically figure out portions of the error message for unknown runners.

sdk/src/test/java/com/google/cloud/dataflow/sdk/options/PipelineOptionsFactoryTest.java

@@ -17,6 +17,7 @@
 package com.google.cloud.dataflow.sdk.options;
 
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasItem;
 import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -53,10 +54,14 @@
 import java.io.PrintStream;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /** Tests for {@link PipelineOptionsFactory}. */
 @RunWith(JUnit4.class)
 public class PipelineOptionsFactoryTest {
+  private static final Class<? extends PipelineRunner<?>> DEFAULT_RUNNER_CLASS =
+      DirectPipelineRunner.class;
+
   @Rule public ExpectedException expectedException = ExpectedException.none();
   @Rule public TestRule restoreSystemProperties = new RestoreSystemProperties();
   @Rule public ExpectedLogs expectedLogs = ExpectedLogs.none(PipelineOptionsFactory.class);
@@ -68,8 +73,9 @@ public void testAutomaticRegistrationOfPipelineOptions() {
 
   @Test
   public void testAutomaticRegistrationOfRunners() {
-    assertEquals(DirectPipelineRunner.class,
-        PipelineOptionsFactory.getRegisteredRunners().get("DirectPipelineRunner"));
+    assertEquals(
+        DEFAULT_RUNNER_CLASS,
+        PipelineOptionsFactory.getRegisteredRunners().get(DEFAULT_RUNNER_CLASS.getSimpleName()));
   }
 
   @Test
@@ -840,9 +846,14 @@ public void testSettingRunnerFullName() {
   public void testSettingUnknownRunner() {
     String[] args = new String[] {"--runner=UnknownRunner"};
     expectedException.expect(IllegalArgumentException.class);
-    expectedException.expectMessage("Unknown 'runner' specified 'UnknownRunner', supported "
-        + "pipeline runners [BlockingDataflowPipelineRunner, DataflowPipelineRunner, "
-        + "DirectPipelineRunner]");
+    expectedException.expectMessage(
+        "Unknown 'runner' specified 'UnknownRunner', supported " + "pipeline runners");
+    Set<String> registeredRunners = PipelineOptionsFactory.getRegisteredRunners().keySet();
+    assertThat(registeredRunners, hasItem(DEFAULT_RUNNER_CLASS.getSimpleName()));
+    for (String registeredRunner : registeredRunners) {
+      expectedException.expectMessage(registeredRunner);
+    }
+
     PipelineOptionsFactory.fromArgs(args).create();
   }
 
@@ -927,13 +938,19 @@ public void testUsingArgumentStartingWithIllegalCharacterIsIgnoredWithoutStrictP
 
   @Test
   public void testEmptyArgumentIsIgnored() {
-    String[] args = new String[] {"", "--diskSizeGb=100", "", "", "--runner=DirectPipelineRunner"};
+    String[] args =
+        new String[] {
+          "", "--diskSizeGb=100", "", "", "--runner=" + DEFAULT_RUNNER_CLASS.getSimpleName()
+        };
     PipelineOptionsFactory.fromArgs(args).create();
   }
 
   @Test
   public void testNullArgumentIsIgnored() {
-    String[] args = new String[] {"--diskSizeGb=100", null, null, "--runner=DirectPipelineRunner"};
+    String[] args =
+        new String[] {
+          "--diskSizeGb=100", null, null, "--runner=" + DEFAULT_RUNNER_CLASS.getSimpleName()
+        };
     PipelineOptionsFactory.fromArgs(args).create();
   }
 
@@ -985,7 +1002,7 @@ public void testSpecificHelpAsArgument() {
     String output = new String(baos.toByteArray());
     assertThat(output, containsString("com.google.cloud.dataflow.sdk.options.PipelineOptions"));
     assertThat(output, containsString("--runner"));
-    assertThat(output, containsString("Default: DirectPipelineRunner"));
+    assertThat(output, containsString("Default: " + DEFAULT_RUNNER_CLASS.getSimpleName()));
     assertThat(output,
         containsString("The pipeline runner that will be used to execute the pipeline."));
   }
@@ -1000,7 +1017,7 @@ public void testSpecificHelpAsArgumentWithSimpleClassName() {
     String output = new String(baos.toByteArray());
     assertThat(output, containsString("com.google.cloud.dataflow.sdk.options.PipelineOptions"));
     assertThat(output, containsString("--runner"));
-    assertThat(output, containsString("Default: DirectPipelineRunner"));
+    assertThat(output, containsString("Default: " + DEFAULT_RUNNER_CLASS.getSimpleName()));
     assertThat(output,
         containsString("The pipeline runner that will be used to execute the pipeline."));
   }
@@ -1015,7 +1032,7 @@ public void testSpecificHelpAsArgumentWithClassNameSuffix() {
     String output = new String(baos.toByteArray());
     assertThat(output, containsString("com.google.cloud.dataflow.sdk.options.PipelineOptions"));
     assertThat(output, containsString("--runner"));
-    assertThat(output, containsString("Default: DirectPipelineRunner"));
+    assertThat(output, containsString("Default: " + DEFAULT_RUNNER_CLASS.getSimpleName()));
     assertThat(output,
         containsString("The pipeline runner that will be used to execute the pipeline."));
   }
@@ -1096,7 +1113,7 @@ public void testProgrammaticPrintHelpForSpecificType() {
     String output = new String(baos.toByteArray());
     assertThat(output, containsString("com.google.cloud.dataflow.sdk.options.PipelineOptions"));
     assertThat(output, containsString("--runner"));
-    assertThat(output, containsString("Default: DirectPipelineRunner"));
+    assertThat(output, containsString("Default: " + DEFAULT_RUNNER_CLASS.getSimpleName()));
     assertThat(output,
         containsString("The pipeline runner that will be used to execute the pipeline."));
   }