[JUnit/TestNG] Always print snippets for undefined steps

CHANGELOG.md

@@ -3,16 +3,10 @@ Please see [CONTRIBUTING.md](https://github.com/cucumber/cucumber/blob/master/CO
 
 ## [4.7.2-SNAPSHOT](https://github.com/cucumber/cucumber-jvm/compare/v4.7.1...master) (In Git)
 
-### Added
-
-### Changed
-
-### Deprecated
-
-### Removed
-
 ### Fixed
-
+ * [JUnit] JUnit will always print unused steps (M.P. Korstanje) 
+ * [TestNG] TestNG will always print unused steps (M.P. Korstanje)
+
 ## [4.7.1-SNAPSHOT](https://github.com/cucumber/cucumber-jvm/compare/v4.7.0...v4.7.1) (2019-07-28)
 
 ### Fixed

core/src/main/java/cucumber/runtime/formatter/PluginFactory.java

@@ -43,6 +43,7 @@ public final class PluginFactory {
         put("json", JSONFormatter.class);
         put("usage", UsageFormatter.class);
         put("rerun", RerunFormatter.class);
+        put("undefined", UndefinedStepsPrinter.class);
         put("default_summary", DefaultSummaryPrinter.class);
         put("summary", DefaultSummaryPrinter.class);
         put("null_summary", NullSummaryPrinter.class);

core/src/main/java/cucumber/runtime/formatter/UndefinedStepsPrinter.java

@@ -0,0 +1,48 @@
+package cucumber.runtime.formatter;
+
+import cucumber.api.event.EventHandler;
+import cucumber.api.event.EventListener;
+import cucumber.api.event.EventPublisher;
+import cucumber.api.event.TestRunFinished;
+import cucumber.runtime.UndefinedStepsTracker;
+
+import java.io.PrintStream;
+import java.util.List;
+
+class UndefinedStepsPrinter implements EventListener {
+
+    private final UndefinedStepsTracker undefinedStepsTracker = new UndefinedStepsTracker();
+
+    private final PrintStream out;
+
+    public UndefinedStepsPrinter() {
+        this.out = System.out;
+    }
+
+    private void print() {
+        printSnippets();
+    }
+
+    private void printSnippets() {
+        List<String> snippets = undefinedStepsTracker.getSnippets();
+        if (!snippets.isEmpty()) {
+            out.append("\n");
+            out.println("There were undefined steps. You can implement missing steps with the snippets below:");
+            out.println();
+            for (String snippet : snippets) {
+                out.println(snippet);
+            }
+        }
+    }
+
+    @Override
+    public void setEventPublisher(EventPublisher publisher) {
+        undefinedStepsTracker.setEventPublisher(publisher);
+        publisher.registerHandlerFor(TestRunFinished.class, new EventHandler<TestRunFinished>() {
+            @Override
+            public void receive(TestRunFinished event) {
+                print();
+            }
+        });
+    }
+}

core/src/main/java/io/cucumber/core/options/RuntimeOptions.java

@@ -47,6 +47,12 @@ public static RuntimeOptions defaultOptions() {
         return new RuntimeOptions();
     }
 
+    public void addUndefinedStepsPrinterIfSummaryNotDefined() {
+        if (pluginSummaryPrinterNames.isEmpty()) {
+            pluginSummaryPrinterNames.add("undefined");
+        }
+    }
+
     public int getCount() {
         return count;
     }

junit/src/main/java/io/cucumber/junit/Cucumber.java

@@ -11,10 +11,7 @@
 import cucumber.runtime.BackendSupplier;
 import cucumber.runtime.ClassFinder;
 import cucumber.runtime.Env;
-import io.cucumber.core.options.EnvironmentOptionsParser;
 import cucumber.runtime.FeaturePathFeatureSupplier;
-import io.cucumber.core.options.RuntimeOptions;
-import io.cucumber.core.options.CucumberOptionsAnnotationParser;
 import cucumber.runtime.filter.Filters;
 import cucumber.runtime.formatter.PluginFactory;
 import cucumber.runtime.formatter.Plugins;
@@ -23,6 +20,9 @@
 import cucumber.runtime.io.ResourceLoaderClassFinder;
 import cucumber.runtime.model.CucumberFeature;
 import cucumber.runtime.model.FeatureLoader;
+import io.cucumber.core.options.CucumberOptionsAnnotationParser;
+import io.cucumber.core.options.EnvironmentOptionsParser;
+import io.cucumber.core.options.RuntimeOptions;
 import org.apiguardian.api.API;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -95,6 +95,8 @@ public Cucumber(Class clazz) throws InitializationError {
             .parse(Env.INSTANCE)
             .build(annotationOptions);
 
+        runtimeOptions.addUndefinedStepsPrinterIfSummaryNotDefined();
+
         JUnitOptions junitAnnotationOptions = new JUnitOptionsParser()
             .parse(clazz)
             .build();

testng/src/main/java/io/cucumber/testng/TestNGCucumberRunner.java

@@ -2,8 +2,16 @@
 
 import cucumber.api.event.TestRunFinished;
 import cucumber.api.event.TestRunStarted;
-import cucumber.runner.*;
-import cucumber.runtime.*;
+import cucumber.runner.EventBus;
+import cucumber.runner.Runner;
+import cucumber.runner.ThreadLocalRunnerSupplier;
+import cucumber.runner.TimeService;
+import cucumber.runner.TimeServiceEventBus;
+import cucumber.runtime.BackendModuleBackendSupplier;
+import cucumber.runtime.ClassFinder;
+import cucumber.runtime.CucumberException;
+import cucumber.runtime.Env;
+import cucumber.runtime.FeaturePathFeatureSupplier;
 import cucumber.runtime.filter.Filters;
 import cucumber.runtime.formatter.PluginFactory;
 import cucumber.runtime.formatter.Plugins;
@@ -13,9 +21,9 @@
 import cucumber.runtime.model.CucumberFeature;
 import cucumber.runtime.model.FeatureLoader;
 import gherkin.events.PickleEvent;
+import io.cucumber.core.options.CucumberOptionsAnnotationParser;
 import io.cucumber.core.options.EnvironmentOptionsParser;
 import io.cucumber.core.options.RuntimeOptions;
-import io.cucumber.core.options.CucumberOptionsAnnotationParser;
 import org.apiguardian.api.API;
 
 import java.util.ArrayList;
@@ -52,6 +60,8 @@ public TestNGCucumberRunner(Class clazz) {
             .parse(Env.INSTANCE)
             .build(annotationOptions);
 
+        runtimeOptions.addUndefinedStepsPrinterIfSummaryNotDefined();
+
         ClassFinder classFinder = new ResourceLoaderClassFinder(resourceLoader, classLoader);
         BackendModuleBackendSupplier backendSupplier = new BackendModuleBackendSupplier(resourceLoader, classFinder, runtimeOptions);
         bus = new TimeServiceEventBus(TimeService.SYSTEM);