Assert decision logger contents

Use ClassRule to only initialize the JenkinsRule once for all tests in
the class.  Makes the tests faster on Linux and much faster on Windows.

Remove unused variable declarations

Split the BeforeClass tasks to separate methods for clarity.

src/test/java/jenkins/advancedqueue/jobinclusion/strategy/FolderBasedJobInclusionStrategyTest.java

@@ -1,38 +1,60 @@
 package jenkins.advancedqueue.jobinclusion.strategy;
 
-import static org.junit.Assert.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 
 import com.cloudbees.hudson.plugins.folder.Folder;
 import hudson.model.FreeStyleProject;
 import hudson.util.ListBoxModel;
+import java.util.ArrayList;
+import java.util.List;
 import jenkins.advancedqueue.DecisionLogger;
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Rule;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.jvnet.hudson.test.JenkinsRule;
 
 public class FolderBasedJobInclusionStrategyTest {
 
-    @Rule
-    public JenkinsRule jenkinsRule = new JenkinsRule();
+    @ClassRule
+    public static JenkinsRule j = new JenkinsRule();
 
-    private FolderBasedJobInclusionStrategy strategy;
+    private static FolderBasedJobInclusionStrategy strategy;
     private static DecisionLogger decisionLogger;
+    private static List<String> loggedMessages;
 
-    @Before
-    public void setUp() throws Exception {
+    @BeforeClass
+    public static void createStrategy() throws Exception {
         strategy = new FolderBasedJobInclusionStrategy("testFolder");
+    }
+
+    @BeforeClass
+    public static void createDecisionLogger() throws Exception {
         decisionLogger = new DecisionLogger() {
             @Override
             public DecisionLogger addDecisionLog(int indent, String log) {
-                return null;
+                loggedMessages.add(log);
+                return this;
             }
         };
     }
 
+    @Before
+    public void clearLoggedMessages() throws Exception {
+        loggedMessages = new ArrayList<>();
+    }
+
     @After
-    public void tearDown() throws Exception {}
+    public void checkLoggedMessages() throws Exception {
+        assertThat(loggedMessages, is(empty()));
+    }
 
     @Test
     public void getDescriptor() {
@@ -54,23 +76,23 @@ public void getFolderName() {
 
     @Test
     public void contains() throws Exception {
-        FreeStyleProject j = jenkinsRule.createFreeStyleProject("testFolder_jobName");
+        FreeStyleProject project = this.j.createFreeStyleProject("testFolder_jobName");
 
-        assertTrue(strategy.contains(decisionLogger, j));
+        assertTrue(strategy.contains(decisionLogger, project));
     }
 
     @Test
     public void containsReturnsFalseForJobNotInFolder() throws Exception {
-        FreeStyleProject j = jenkinsRule.createFreeStyleProject("otherFolder_jobName");
+        FreeStyleProject project = j.createFreeStyleProject("otherFolder_jobName");
 
-        assertFalse(strategy.contains(decisionLogger, j));
+        assertFalse(strategy.contains(decisionLogger, project));
     }
 
     @Test
     public void containsReturnsTrueForJobInSubFolder() throws Exception {
-        FreeStyleProject j = jenkinsRule.createFreeStyleProject("testFolder_subFolder_jobName");
+        FreeStyleProject project = j.createFreeStyleProject("testFolder_subFolder_jobName");
 
-        assertTrue(strategy.contains(decisionLogger, j));
+        assertTrue(strategy.contains(decisionLogger, project));
     }
 
     @Test
@@ -84,8 +106,8 @@ public void getListFolderItemsReturnsNonNullListBoxModel() {
     @Test
     public void getListFolderItemsReturnsCorrectFolderNames() throws Exception {
 
-        Folder folder1 = jenkinsRule.jenkins.createProject(Folder.class, "folder1");
-        Folder folder2 = jenkinsRule.jenkins.createProject(Folder.class, "folder2");
+        j.jenkins.createProject(Folder.class, "folder1");
+        j.jenkins.createProject(Folder.class, "folder2");
 
         FolderBasedJobInclusionStrategy.FolderBasedJobInclusionStrategyDescriptor descriptor =
                 new FolderBasedJobInclusionStrategy.FolderBasedJobInclusionStrategyDescriptor();