Migrate tests to JUnit5

* Migrate annotations and imports
* Migrate assertions
* Remove public visibility for test classes and methods
* Minor code cleanup

Author: strangelookingnerd

pom.xml

@@ -204,11 +204,6 @@
       <artifactId>test-harness</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>nl.jqno.equalsverifier</groupId>
       <artifactId>equalsverifier</artifactId>
@@ -236,7 +231,7 @@
     </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
+      <artifactId>mockito-junit-jupiter</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>

src/test/java/hudson/plugins/git/BranchTest.java

@@ -7,56 +7,45 @@
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectIdRef;
 import org.eclipse.jgit.lib.Ref;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-public class BranchTest {
+class BranchTest {
 
-    private final String branchSHA1;
-    private final String branchName;
-    private final ObjectId branchHead;
-    private final Branch branch;
-    private final String refPrefix;
-    private final Ref branchRef;
-    private final Branch branchFromRef;
-
-    private static final String REMOTE_BRANCH_NAME = "origin/master";
-
-    public BranchTest() {
-        this.branchSHA1 = "fa71f704f9b90fa1f857d1623f3fe33fa2277ca9";
-        this.branchName = REMOTE_BRANCH_NAME;
-        this.branchHead = ObjectId.fromString(branchSHA1);
-        this.refPrefix = "refs/remotes/";
-        this.branchRef = new ObjectIdRef.PeeledNonTag(Ref.Storage.NEW, refPrefix + branchName, branchHead);
-        this.branch = new Branch(branchName, branchHead);
-        this.branchFromRef = new Branch(branchRef);
-    }
+    private static final String BRANCH_SHA_1 = "fa71f704f9b90fa1f857d1623f3fe33fa2277ca9";
+    private static final String BRANCH_NAME = "origin/master";
+    private static final ObjectId BRANCH_HEAD = ObjectId.fromString(BRANCH_SHA_1);
+    private static final Branch BRANCH = new Branch(BRANCH_NAME, BRANCH_HEAD);
+    private static final String REF_PREFIX = "refs/remotes/";
+    private static final Ref BRANCH_REF =
+            new ObjectIdRef.PeeledNonTag(Ref.Storage.NEW, REF_PREFIX + BRANCH_NAME, BRANCH_HEAD);
+    private static final Branch BRANCH_FROM_REF = new Branch(BRANCH_REF);
 
     @Test
-    public void testToString() {
-        assertThat(branch.toString(), is(branchFromRef.toString()));
+    void testToString() {
+        assertThat(BRANCH.toString(), is(BRANCH_FROM_REF.toString()));
     }
 
     @Test
-    public void testToString_Contents() {
-        String expected = "Branch " + branchName + "(" + branchSHA1 + ")";
-        assertThat(branch.toString(), is(expected));
+    void testToString_Contents() {
+        String expected = "Branch " + BRANCH_NAME + "(" + BRANCH_SHA_1 + ")";
+        assertThat(BRANCH.toString(), is(expected));
     }
 
     @Test
-    public void hashCodeContract() {
-        assertThat(branch, is(branchFromRef));
-        assertThat(branch.hashCode(), is(branchFromRef.hashCode()));
+    void hashCodeContract() {
+        assertThat(BRANCH, is(BRANCH_FROM_REF));
+        assertThat(BRANCH.hashCode(), is(BRANCH_FROM_REF.hashCode()));
     }
 
     @Test
-    public void constructorRefArgStripped() {
-        Ref ref = new ObjectIdRef.PeeledNonTag(Ref.Storage.LOOSE, refPrefix + branchName, branchHead);
+    void constructorRefArgStripped() {
+        Ref ref = new ObjectIdRef.PeeledNonTag(Ref.Storage.LOOSE, REF_PREFIX + BRANCH_NAME, BRANCH_HEAD);
         Branch strippedBranch = new Branch(ref);
-        assertThat(strippedBranch.getName(), is(branchName));
+        assertThat(strippedBranch.getName(), is(BRANCH_NAME));
     }
 
     @Test
-    public void equalsContract() {
+    void equalsContract() {
         EqualsVerifier.forClass(Branch.class)
                 .usingGetClass()
                 .withRedefinedSuperclass()

src/test/java/hudson/plugins/git/GitAPIBadInitTest.java

@@ -2,8 +2,8 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
-import static org.junit.Assert.assertThrows;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import hudson.EnvVars;
 import hudson.model.TaskListener;
@@ -13,46 +13,50 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import org.jenkinsci.plugins.gitclient.GitClient;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
-public class GitAPIBadInitTest {
+class GitAPIBadInitTest {
 
-    @Rule
-    public TemporaryFolder tempFolder = new TemporaryFolder();
+    @TempDir
+    private File tempFolder;
 
-    private final EnvVars env;
-
-    public GitAPIBadInitTest() {
-        env = new EnvVars();
-    }
+    private final EnvVars env = new EnvVars();
 
     private File tempDir;
     private TaskListener listener;
 
-    @Before
-    public void setUp() throws IOException, InterruptedException {
-        tempDir = tempFolder.newFolder();
+    @BeforeEach
+    void setUp() throws Exception {
+        tempDir = newFolder(tempFolder, "junit");
         listener = StreamTaskListener.fromStderr();
     }
 
     @Test
-    public void testInitExistingDirectory() throws Exception {
+    void testInitExistingDirectory() throws Exception {
         GitClient git = new GitAPI("git", tempDir, listener, env);
         git.init();
         File gitDir = new File(tempDir, ".git");
-        assertTrue(gitDir + " not created", gitDir.exists());
-        assertTrue(gitDir + " not a directory", gitDir.isDirectory());
+        assertTrue(gitDir.exists(), gitDir + " not created");
+        assertTrue(gitDir.isDirectory(), gitDir + " not a directory");
     }
 
     @Test
-    public void testInitExistingFile() throws Exception {
+    void testInitExistingFile() throws Exception {
         File existingFile = new File(tempDir, "file-exists");
         Files.writeString(existingFile.toPath(), "git init should fail due to this file", StandardCharsets.UTF_8);
         GitClient git = new GitAPI("git", existingFile, listener, env);
         GitException e = assertThrows(GitException.class, git::init);
         assertThat(e.getMessage(), is("Could not init " + existingFile.getAbsolutePath()));
     }
+
+    private static File newFolder(File root, String... subDirs) throws Exception {
+        String subFolder = String.join("/", subDirs);
+        File result = new File(root, subFolder);
+        if (!result.exists() && !result.mkdirs()) {
+            throw new IOException("Couldn't create folders " + root);
+        }
+        return result;
+    }
 }

src/test/java/hudson/plugins/git/GitExceptionTest.java

@@ -5,37 +5,35 @@
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.isA;
 import static org.hamcrest.Matchers.nullValue;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import hudson.EnvVars;
 import hudson.model.TaskListener;
 import java.io.File;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.jenkinsci.plugins.gitclient.Git;
 import org.jenkinsci.plugins.gitclient.GitClient;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
-public class GitExceptionTest {
+class GitExceptionTest {
 
-    @Rule
-    public TemporaryFolder folder = new TemporaryFolder();
+    @TempDir
+    private File folder;
 
     @Test
-    public void throwsGitException() {
+    void throwsGitException() {
         GitException e = assertThrows(GitException.class, () -> {
             throw new GitException();
         });
         assertThat(e.getMessage(), is(nullValue()));
     }
 
     @Test
-    public void throwsGitExceptionExpectedMessage() {
+    void throwsGitExceptionExpectedMessage() {
         String message = "My custom git exception message";
         GitException e = assertThrows(GitException.class, () -> {
             throw new GitException(message);
@@ -44,7 +42,7 @@ public void throwsGitExceptionExpectedMessage() {
     }
 
     @Test
-    public void throwsGitExceptionExpectedMessageWithCause() {
+    void throwsGitExceptionExpectedMessageWithCause() {
         String message = "My custom git exception message";
         GitException e = assertThrows(GitException.class, () -> {
             throw new GitException(message, new IOException("Custom IOException message"));
@@ -54,7 +52,7 @@ public void throwsGitExceptionExpectedMessageWithCause() {
     }
 
     @Test
-    public void initCliImplThrowsGitException() throws IOException, InterruptedException {
+    void initCliImplThrowsGitException() throws Exception {
         if (new File("/").canWrite()) { // running as root?
             return;
         }
@@ -72,7 +70,7 @@ public void initCliImplThrowsGitException() throws IOException, InterruptedExcep
     }
 
     @Test
-    public void initJGitImplThrowsGitException() throws IOException, InterruptedException {
+    void initJGitImplThrowsGitException() throws Exception {
         if (new File("/").canWrite()) { // running as root?
             return;
         }
@@ -91,10 +89,10 @@ public void initJGitImplThrowsGitException() throws IOException, InterruptedExce
     }
 
     @Test
-    public void initCliImplCollisionThrowsGitException() throws IOException, InterruptedException {
-        File dir = folder.getRoot();
-        File dotGit = folder.newFile(".git");
-        Files.write(dotGit.toPath(), "file named .git".getBytes(StandardCharsets.UTF_8), APPEND);
+    void initCliImplCollisionThrowsGitException() throws Exception {
+        File dir = folder;
+        File dotGit = newFile(folder, ".git");
+        Files.writeString(dotGit.toPath(), "file named .git", APPEND);
         GitClient defaultClient =
                 Git.with(TaskListener.NULL, new EnvVars()).in(dir).using("git").getClient();
         assertThrows(
@@ -103,10 +101,10 @@ public void initCliImplCollisionThrowsGitException() throws IOException, Interru
     }
 
     @Test
-    public void initJGitImplCollisionThrowsGitException() throws IOException, InterruptedException {
-        File dir = folder.getRoot();
-        File dotGit = folder.newFile(".git");
-        Files.write(dotGit.toPath(), "file named .git".getBytes(StandardCharsets.UTF_8), APPEND);
+    void initJGitImplCollisionThrowsGitException() throws Exception {
+        File dir = folder;
+        File dotGit = newFile(folder, ".git");
+        Files.writeString(dotGit.toPath(), "file named .git", APPEND);
         GitClient defaultClient =
                 Git.with(TaskListener.NULL, new EnvVars()).in(dir).using("jgit").getClient();
         JGitInternalException e = assertThrows(
@@ -122,4 +120,12 @@ public void initJGitImplCollisionThrowsGitException() throws IOException, Interr
     private static boolean isWindows() {
         return File.pathSeparatorChar == ';';
     }
+
+    private static File newFile(File parent, String child) throws Exception {
+        File result = new File(parent, child);
+        if (!result.createNewFile()) {
+            throw new IOException("Couldn't create file " + result);
+        }
+        return result;
+    }
 }

src/test/java/hudson/plugins/git/GitLockFailedExceptionTest.java

@@ -3,22 +3,22 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-public class GitLockFailedExceptionTest {
+class GitLockFailedExceptionTest {
 
     @Test
-    public void throwsGitLockFailedException() {
+    void throwsGitLockFailedException() {
         GitLockFailedException lockFailed = assertThrows(GitLockFailedException.class, () -> {
             throw new GitLockFailedException();
         });
         assertThat(lockFailed.getMessage(), is(nullValue()));
     }
 
     @Test
-    public void throwsGitLockFailedExceptionWithMessage() {
+    void throwsGitLockFailedExceptionWithMessage() {
         String message = "My local exception message";
         GitLockFailedException lockFailed = assertThrows(GitLockFailedException.class, () -> {
             throw new GitLockFailedException(message);
@@ -27,7 +27,7 @@ public void throwsGitLockFailedExceptionWithMessage() {
     }
 
     @Test
-    public void throwsGitLockFailedExceptionWithCause() {
+    void throwsGitLockFailedExceptionWithCause() {
         String message = "My git exception message";
         GitException e = new GitException(message);
         GitLockFailedException lockFailed = assertThrows(GitLockFailedException.class, () -> {
@@ -37,7 +37,7 @@ public void throwsGitLockFailedExceptionWithCause() {
     }
 
     @Test
-    public void throwsGitLockFailedExceptionWithCauseAndMessage() {
+    void throwsGitLockFailedExceptionWithCauseAndMessage() {
         String message = "My git exception message";
         GitException e = new GitException(message);
         String lockMessage = "My lock message that is not part of the GitException";