Allow ColorAware, StrictAware and EventListener as mixins Plugin

Author: mpkorstanje

Diff for: core/src/main/java/cucumber/api/Plugin.java

@@ -29,6 +29,14 @@
  * </ul>
  * <p>
  * To make the parameter optional the plugin must also have a public default constructor.
+ * <p>
+ * Plugins may also implement one of these interfaces:
+ * <ul>
+ * <li>{@link cucumber.api.formatter.ColorAware}</li>
+ * <li>{@link cucumber.api.formatter.StrictAware}</li>
+ * <li>{@link cucumber.api.event.EventListener}</li>
+ * </ul>
+ * <p>
  */
 public interface Plugin {
 }

Diff for: core/src/main/java/cucumber/api/event/EventListener.java

@@ -1,8 +1,7 @@
 package cucumber.api.event;
 
 /**
- * This is the interface you should implement if you want your own custom
- * formatter.
+ * This is the interface you should implement if your plugin listens to cucumber execution events
  */
 public interface EventListener {
 

Diff for: core/src/main/java/cucumber/runtime/DefaultSummaryPrinter.java

@@ -2,16 +2,16 @@
 
 import cucumber.api.SummaryPrinter;
 import cucumber.api.event.EventHandler;
+import cucumber.api.event.EventListener;
 import cucumber.api.event.EventPublisher;
 import cucumber.api.event.TestRunFinished;
 import cucumber.api.formatter.ColorAware;
-import cucumber.api.formatter.Formatter;
 import cucumber.api.formatter.StrictAware;
 
 import java.io.PrintStream;
 import java.util.List;
 
-public class DefaultSummaryPrinter implements SummaryPrinter, ColorAware, StrictAware, Formatter {
+public class DefaultSummaryPrinter implements SummaryPrinter, ColorAware, StrictAware, EventListener {
 
     private final Stats stats = new Stats();
     private final UndefinedStepsTracker undefinedStepsTracker = new UndefinedStepsTracker();

Diff for: core/src/main/java/cucumber/runtime/RuntimeOptions.java

@@ -3,6 +3,7 @@
 import cucumber.api.Plugin;
 import cucumber.api.SnippetType;
 import cucumber.api.StepDefinitionReporter;
+import cucumber.api.event.EventListener;
 import io.cucumber.datatable.DataTable;
 import cucumber.api.event.TestRunStarted;
 import cucumber.api.formatter.ColorAware;
@@ -381,8 +382,8 @@ private void setStrictOnStrictAwarePlugins(Object plugin) {
         }
     }
 
-    private void setEventBusFormatterPlugins(Object plugin) {
-        if (plugin instanceof Formatter && bus != null) {
+    private void setEventBusOnEventListenerPlugins(Object plugin) {
+        if (plugin instanceof EventListener && bus != null) {
             Formatter formatter = (Formatter) plugin;
             formatter.setEventPublisher(bus);
         }
@@ -408,7 +409,7 @@ public void addPlugin(Plugin plugin) {
         plugins.add(plugin);
         setMonochromeOnColorAwarePlugins(plugin);
         setStrictOnStrictAwarePlugins(plugin);
-        setEventBusFormatterPlugins(plugin);
+        setEventBusOnEventListenerPlugins(plugin);
     }
 
     public List<Pattern> getNameFilters() {