Bring back the Java8StepDefinitionTest in the java module.

The Java8StepDefinitionTest class in the java module tests the
"genericInterface instanceof ParameterizedType" branch of
Java8StepDefinition.getParameterInfos.

Author: brasmusson

java/src/test/java/cucumber/runtime/java/Java8StepDefinitionTest.java

@@ -0,0 +1,76 @@
+package cucumber.runtime.java;
+
+import cucumber.api.java8.StepdefBody;
+import cucumber.runtime.CucumberException;
+import org.junit.Test;
+
+import java.util.List;
+import java.util.regex.Pattern;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class Java8StepDefinitionTest {
+
+    @Test
+    public void should_calculate_parameters_count_from_body_with_one_param() throws Exception {
+        Java8StepDefinition java8StepDefinition = new Java8StepDefinition(Pattern.compile("^I have (\\d) some step (.*)$"), 0, oneParamStep(), null);
+        assertEquals(new Integer(1), java8StepDefinition.getParameterCount());
+    }
+
+    @Test
+    public void should_calculate_parameters_count_from_body_with_two_params() throws Exception {
+        Java8StepDefinition java8StepDefinition = new Java8StepDefinition(Pattern.compile("^I have some step $"), 0, twoParamStep(), null);
+        assertEquals(new Integer(2), java8StepDefinition.getParameterCount());
+    }
+
+    @Test
+    public void should_fail_for_param_with_non_generic_list() throws Exception {
+        try {
+            new Java8StepDefinition(Pattern.compile("^I have (\\d) some step (.*)$"), 0, nonGenericListStep(), null);
+            fail();
+        } catch (CucumberException expected) {
+            assertEquals("Can't use java.util.List in lambda step definition. Declare a DataTable argument instead and convert manually with asList/asLists/asMap/asMaps", expected.getMessage());
+        }
+    }
+
+    @Test
+    public void should_pass_for_param_with_generic_list() throws Exception {
+        Java8StepDefinition java8StepDefinition = new Java8StepDefinition(Pattern.compile("^I have (\\d) some step (.*)$"), 0, genericListStep(), null);
+        assertEquals(new Integer(1), java8StepDefinition.getParameterCount());
+    }
+
+    private StepdefBody oneParamStep() {
+        return new StepdefBody.A1<String>() {
+            @Override
+            public void accept(String p1) {
+            }
+        };
+    }
+
+    private StepdefBody twoParamStep() {
+        return new StepdefBody.A2<String, String>() {
+            @Override
+            public void accept(String p1, String p2) {
+            }
+        };
+    }
+
+    private StepdefBody genericListStep() {
+        return new StepdefBody.A1<List<String>>() {
+            @Override
+            public void accept(List<String> p1) {
+                throw new UnsupportedOperationException();
+            }
+        };
+    }
+
+    private StepdefBody nonGenericListStep() {
+        return new StepdefBody.A1<List>() {
+            @Override
+            public void accept(List p1) {
+                throw new UnsupportedOperationException();
+            }
+        };
+    }
+}