[JENKINS-37995] Fix getter value in UI (#143)

Signed-off-by: Kanstantsin Shautsou <kanstantsin.sha@gmail.com>

src/main/java/hudson/plugins/emailext/plugins/trigger/XNthFailureTrigger.java

@@ -24,7 +24,7 @@ public XNthFailureTrigger(List<RecipientProvider> recipientProviders, String rec
     }
 
     @Override
-    protected int getRequiredFailureCount() {
+    public int getRequiredFailureCount() {
         return requiredFailureCount;
     }
 

src/main/resources/hudson/plugins/emailext/plugins/trigger/XNthFailureTrigger/local-config.groovy

@@ -2,6 +2,6 @@ package hudson.plugins.emailext.plugins.trigger.XNthFailureTrigger
 
 f = namespace("/lib/form")
 
-f.entry(title: _("Number Of Failures")) {
-    f.number(name: "requiredFailureCount")
+f.entry(title: _("Number Of Failures"), field: "requiredFailureCount") {
+    f.number()
 }

src/test/java/hudson/plugins/emailext/plugins/trigger/XNthFailureTriggerJTest.java

@@ -0,0 +1,47 @@
+package hudson.plugins.emailext.plugins.trigger;
+
+import hudson.model.FreeStyleProject;
+import hudson.plugins.emailext.ExtendedEmailPublisher;
+import hudson.plugins.emailext.plugins.EmailTrigger;
+import hudson.plugins.emailext.plugins.RecipientProvider;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.JenkinsRule;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * @author Kanstantsin Shautsou
+ */
+public class XNthFailureTriggerJTest {
+    @Rule
+    public JenkinsRule jRule = new JenkinsRule();
+
+    @Test
+    public void testConfigRoundTrip() throws Exception {
+        FreeStyleProject project = jRule.createFreeStyleProject();
+
+        final ExtendedEmailPublisher publisher = new ExtendedEmailPublisher();
+        XNthFailureTrigger trigger = new XNthFailureTrigger(Collections.<RecipientProvider>emptyList(),
+                "", "", "", "", "", 0, "project");
+        trigger.setRequiredFailureCount(5);
+
+        publisher.configuredTriggers.add(trigger);
+        project.getPublishersList().add(publisher);
+        project.save();
+
+        jRule.configRoundtrip(project);
+
+        final FreeStyleProject projectAfter = (FreeStyleProject) jRule.getInstance().getItem(project.getName());
+
+        final ExtendedEmailPublisher rPublisher = projectAfter.getPublishersList().get(ExtendedEmailPublisher.class);
+
+        final XNthFailureTrigger emailTrigger = (XNthFailureTrigger) rPublisher.getConfiguredTriggers().get(0);
+
+        assertThat(emailTrigger.getRequiredFailureCount(), is(5));
+    }
+}