Auto add headless true only using a feature

Pitest automatically adds -Djava.awt.headless=true to the jvm args to
prevent keyboard focu being stolen on macs.

The change introduces a new extention point ConfigurationUpdater
to allow changes to be made to the supplied config.

This interface uses the feature system, so implementations can be
enabled and disabled at runtime.

The previously hard coded adding of headless=true is moved into a
feature. It is enabled by default, but can now be dissabled by passing

features="-macos_focus"

Consideration was given to only adding the param when running on OS X,
but this was decided against and it would make the build inconsistent.

README.md

@@ -11,6 +11,10 @@ Read all about it at http://pitest.org
 ### 1.9.3 (unreleased)
 
 * #1052 - Support maven argLine property and single string argLines
+* #1054 - Provide control over auto addition of -Djava.awt.headless=true
+
+1054 Moves support of auto adding headless=true (to prevent keyboard focus being stolen on Macs) into a feature. 
+It is enabled by default, but can be disabled by adding `-MACOS_FOCUS` to the features string.
 
 ### 1.9.2
 

pitest-command-line/src/test/java/org/pitest/mutationtest/commandline/OptionsParserTest.java

@@ -23,7 +23,6 @@
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.when;
-import static org.pitest.mutationtest.config.ReportOptions.DEFAULT_CHILD_JVM_ARGS;
 
 import java.io.File;
 import java.nio.charset.Charset;
@@ -108,7 +107,6 @@ public void shouldParseCommaSeparatedListOfJVMArgs() {
     final ReportOptions actual = parseAddingRequiredArgs("--jvmArgs", "foo,bar");
 
     List<String> expected = new ArrayList<>();
-    expected.addAll(DEFAULT_CHILD_JVM_ARGS);
     expected.add("foo");
     expected.add("bar");
     assertEquals(expected, actual.getJvmArgs());

pitest-entry/src/main/java/org/pitest/mutationtest/autoconfig/KeepMacOsFocus.java

@@ -0,0 +1,32 @@
+package org.pitest.mutationtest.autoconfig;
+
+import org.pitest.mutationtest.config.ConfigurationUpdater;
+import org.pitest.mutationtest.config.ReportOptions;
+import org.pitest.plugin.Feature;
+
+import static java.util.Collections.singletonList;
+
+/**
+ * Pitest steals keyboard focus in OSX unless java is launched in
+ * headless mode.
+ */
+public class KeepMacOsFocus implements ConfigurationUpdater {
+
+    @Override
+    public void updateConfig(ReportOptions toModify) {
+        toModify.addChildJVMArgs(singletonList("-Djava.awt.headless=true"));
+    }
+
+    @Override
+    public Feature provides() {
+        return Feature.named("MACOS_FOCUS")
+                .withOnByDefault(true)
+                .withDescription(description());
+    }
+
+    @Override
+    public String description() {
+        return "Auto add java.awt.headless=true to keep keyboard focus on Mac OS";
+    }
+
+}

pitest-entry/src/main/java/org/pitest/mutationtest/config/CompoundConfigurationUpdater.java

@@ -0,0 +1,34 @@
+package org.pitest.mutationtest.config;
+
+import org.pitest.plugin.Feature;
+import org.pitest.plugin.FeatureSelector;
+import org.pitest.plugin.FeatureSetting;
+
+import java.util.Collection;
+import java.util.List;
+
+public class CompoundConfigurationUpdater implements ConfigurationUpdater {
+    private final FeatureSelector<ConfigurationUpdater> features;
+
+    public CompoundConfigurationUpdater(List<FeatureSetting> features,
+                                        Collection<ConfigurationUpdater> children) {
+        this.features = new FeatureSelector<>(features, children);
+    }
+
+    @Override
+    public void updateConfig(ReportOptions toModify) {
+        for (ConfigurationUpdater each : features.getActiveFeatures() ) {
+            each.updateConfig(toModify);
+        }
+    }
+
+    @Override
+    public Feature provides() {
+        return Feature.named("n/a");
+    }
+
+    @Override
+    public String description() {
+        return "n/a";
+    }
+}

pitest-entry/src/main/java/org/pitest/mutationtest/config/ConfigurationUpdater.java

@@ -0,0 +1,8 @@
+package org.pitest.mutationtest.config;
+
+import org.pitest.plugin.ProvidesFeature;
+import org.pitest.plugin.ToolClasspathPlugin;
+
+public interface ConfigurationUpdater extends ToolClasspathPlugin, ProvidesFeature {
+    void updateConfig(ReportOptions toModify);
+}

pitest-entry/src/main/java/org/pitest/mutationtest/config/PluginServices.java

@@ -48,6 +48,7 @@ public Collection<? extends ToolClasspathPlugin> findToolClasspathPlugins() {
     l.addAll(findGroupers());
     l.addAll(findTestPrioritisers());
     l.addAll(findInterceptors());
+    l.addAll(findConfigurationUpdaters());
     return l;
   }
 
@@ -64,6 +65,10 @@ public List<? extends ClientClasspathPlugin> findClientClasspathPlugins() {
     return l;
   }
 
+  public Collection<? extends ConfigurationUpdater> findConfigurationUpdaters() {
+    return load(ConfigurationUpdater.class);
+  }
+
   public Collection<? extends MethodMutatorFactory> findMutationOperators() {
     return load(MethodMutatorFactory.class);
   }

pitest-entry/src/main/java/org/pitest/mutationtest/config/ReportOptions.java

@@ -64,8 +64,6 @@
  */
 public class ReportOptions {
 
-  public static final List<String> DEFAULT_CHILD_JVM_ARGS = Collections.singletonList("-Djava.awt.headless=true");
-
   public static final Collection<String> LOGGING_CLASSES                = Arrays
       .asList(
           "java.util.logging",
@@ -96,9 +94,9 @@ public class ReportOptions {
   private Collection<String>             mutators;
   private Collection<String>             features;
 
-  private final List<String>             jvmArgs                        = new ArrayList<>(DEFAULT_CHILD_JVM_ARGS);
 
   private String                         argLine;
+  private final List<String>             jvmArgs                        = new ArrayList<>();
 
   private int                            numberOfThreads                = 0;
   private float                          timeoutFactor                  = PercentAndConstantTimeoutStrategy.DEFAULT_FACTOR;

pitest-entry/src/main/java/org/pitest/mutationtest/config/SettingsFactory.java

@@ -73,6 +73,11 @@ public MutationResultListenerFactory createListener() {
     return new CompoundListenerFactory(parser.parseFeatures(this.options.getFeatures()), findListeners());
   }
 
+  public ConfigurationUpdater createUpdater() {
+    final FeatureParser parser = new FeatureParser();
+    return new CompoundConfigurationUpdater(parser.parseFeatures(this.options.getFeatures()), new ArrayList<>(plugins.findConfigurationUpdaters()));
+  }
+
   public JavaExecutableLocator getJavaExecutable() {
     if (this.options.getJavaExecutable() != null) {
       return new KnownLocationJavaExecutableLocator(

pitest-entry/src/main/java/org/pitest/mutationtest/tooling/EntryPoint.java

@@ -71,6 +71,8 @@ public AnalysisResult execute(File baseDir, ReportOptions data,
   public AnalysisResult execute(File baseDir, ReportOptions data,
       SettingsFactory settings, Map<String, String> environmentVariables) {
 
+    updateData(data, settings);
+
     if (data.getVerbosity() == VERBOSE) {
       Log.getLogger().info("Project base directory is " + data.getProjectBase());
       Log.getLogger().info("---------------------------------------------------------------------------");
@@ -141,6 +143,11 @@ private List<String> createJvmArgs(ReportOptions data) {
     return args;
   }
 
+  private void updateData(ReportOptions data, SettingsFactory settings) {
+    settings.createUpdater().updateConfig(data);
+
+  }
+
   private HistoryStore makeHistoryStore(ReportOptions data,  Optional<WriterFactory> historyWriter) {
     final Optional<Reader> reader = data.createHistoryReader();
     if (!reader.isPresent() && !historyWriter.isPresent()) {

pitest-entry/src/main/resources/META-INF/services/org.pitest.mutationtest.config.ConfigurationUpdater

@@ -0,0 +1 @@
+org.pitest.mutationtest.autoconfig.KeepMacOsFocus

pitest-entry/src/test/java/org/pitest/mutationtest/autoconfig/KeepMacOsFocusTest.java

@@ -0,0 +1,32 @@
+package org.pitest.mutationtest.autoconfig;
+
+import org.junit.Test;
+import org.pitest.mutationtest.config.ReportOptions;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class KeepMacOsFocusTest {
+    KeepMacOsFocus underTest = new KeepMacOsFocus();
+
+    @Test
+    public void addsHeadlessTrueToJvmArgs() {
+        ReportOptions data = new ReportOptions();
+
+        underTest.updateConfig(data);
+        assertThat(data.getJvmArgs()).contains("-Djava.awt.headless=true");
+    }
+
+    @Test
+    public void featureIsNamedMacOsFocus() {
+        KeepMacOsFocus underTest = new KeepMacOsFocus();
+
+        assertThat(underTest.provides().name()).isEqualTo("macos_focus");
+    }
+
+    @Test
+    public void featureIsOnByDefault() {
+        KeepMacOsFocus underTest = new KeepMacOsFocus();
+
+        assertThat(underTest.provides().isOnByDefault()).isTrue();
+    }
+}

pitest-maven-verification/src/test/java/org/pitest/PitMojoIT.java

@@ -373,11 +373,6 @@ public void shouldWorkWithGWTMockito() throws Exception {
     assertThat(actual).doesNotContain("status='RUN_ERROR'");
   }
 
-  private void skipIfJavaVersionNotSupportByThirdParty() {
-    String javaVersion = System.getProperty("java.version");
-    assumeFalse(javaVersion.startsWith("9") || javaVersion.startsWith("10") || javaVersion.startsWith("11"));
-  }
-
   @Test
   @Ignore("yatspec is not available on maven central. Repo currently down")
   public void shouldWorkWithYatspec() throws Exception {
@@ -451,6 +446,12 @@ public void shouldFailCleanlyWhenTestPluginMissing() throws IOException {
   }
 
 
+  private void skipIfJavaVersionNotSupportByThirdParty() {
+    String javaVersion = System.getProperty("java.version");
+    assumeFalse(javaVersion.startsWith("9") || javaVersion.startsWith("10") || javaVersion.startsWith("11"));
+  }
+
+
   private static String readResults(File testDir) throws IOException {
     File mutationReport = new File(testDir.getAbsoluteFile() + File.separator
             + "target" + File.separator + "pit-reports" + File.separator

pitest-maven/src/test/java/org/pitest/maven/MojoToReportOptionsConverterTest.java

@@ -108,7 +108,6 @@ public void testParsesListOfJVMArgs() {
     final ReportOptions actual = parseConfig(xml);
 
     List<String> expectedArgs = new ArrayList<>();
-    expectedArgs.addAll(ReportOptions.DEFAULT_CHILD_JVM_ARGS);
     expectedArgs.add("foo");
     expectedArgs.add("bar");