junit4 - fix npe for tests in default package (via #134)

Author: jkttt

allure-junit4/src/main/java/io/qameta/allure/junit4/AllureJunit4.java

@@ -232,7 +232,10 @@ private MessageDigest getMessageDigest() {
     }
 
     private String getPackage(final Class<?> testClass) {
-        return testClass.getPackage().getName();
+        return Optional.of(testClass)
+                .map(Class::getPackage)
+                .map(Package::getName)
+                .orElse("");
     }
 
     private StatusDetails getIgnoredMessage(final Description description) {

allure-junit4/src/test/java/SampleTestInDefaultPackage.java

@@ -0,0 +1,12 @@
+import org.junit.Test;
+
+/**
+ * @author jkt on 15.08.17.
+ */
+public class SampleTestInDefaultPackage {
+
+    @Test
+    public void testMethod() {
+
+    }
+}

allure-junit4/src/test/java/io/qameta/allure/junit4/FeatureCombinationsTest.java

@@ -23,6 +23,7 @@
 import org.junit.Test;
 import org.junit.runner.JUnitCore;
 import org.junit.runner.Request;
+import org.junit.runner.Result;
 
 import java.util.List;
 
@@ -224,4 +225,12 @@ public void shouldSetTags() throws Exception {
                 .extracting(Label::getValue)
                 .containsExactlyInAnyOrder(CLASS_TAG1, CLASS_TAG2, METHOD_TAG1, METHOD_TAG2);
     }
+
+    @Test
+    @DisplayName("Should not throw exception processing test from default package")
+    public void shouldProcessTestFromDefaultPackage() throws Exception {
+        Class<?> testInDefaultPackage = Class.forName("SampleTestInDefaultPackage");
+        Result result = core.run(Request.aClass(testInDefaultPackage));
+        assertThat(result.wasSuccessful()).isTrue();
+    }
 }