Migrate tests to JUnit5

Squashed commit of the following:

commit 5567afe
Author: git-client-user <[email protected]>
Date:   Tue Sep 9 09:28:13 2025 +0200

    Do not create temporary files in project root

commit d95a472
Merge: 4231ffe 3a4021b
Author: Mark Waite <[email protected]>
Date:   Mon Sep 8 06:39:21 2025 -0600

    Merge branch 'master' into migrate_to_junit5

commit 4231ffe
Author: git-client-user <[email protected]>
Date:   Sat Sep 6 18:28:55 2025 -0600

    Fix code formatting

    Spotless

commit 357ada8
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 17:17:42 2025 -0600

    Skip testSparseCheckoutWithCliGitLFS on CI

    Unreliable due to GitHub message

commit e26556f
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 12:34:13 2025 -0600

    Improve JMH sample repository choices

    Include a wider range of small repositories in order to be more likely
    to detect shifts in the turning point where command line git performs
    better than JGit.

    Current data shows that JGit is faster than command line git for
    repositories up to 8 MB.  Command line git is dramatically faster than
    JGit for the 450 MB repository that is the largest repository used in
    the test.

commit f908818
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 07:58:11 2025 -0600

    Ban JUnit 4 imports

commit 9f25a4e
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 07:56:20 2025 -0600

    Correct comments in FolderForBenchmark

commit b3534e1
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 07:23:15 2025 -0600

    Use repository matching comment - cairoshell

commit 73adf26
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 07:17:02 2025 -0600

    Convert JGitAPIImplUnsupportedProtocolTest to JUnit 5

commit 97fdc99
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 06:57:55 2025 -0600

    Remove vanilla benchmark test

commit 2a893fd
Merge: d86a764 10c56e5
Author: Mark Waite <[email protected]>
Date:   Sat Sep 6 06:47:24 2025 -0600

    Merge branch 'master' into migrate_to_junit5

commit d86a764
Author: strangelookingnerd <[email protected]>
Date:   Mon Aug 25 13:46:26 2025 +0200

    Fix file cleanup

commit 690422e
Author: strangelookingnerd <[email protected]>
Date:   Mon Aug 25 08:45:02 2025 +0200

    Restore dependency declaration

commit 8510a07
Merge: 6e3b929 ca8f10b
Author: Mark Waite <[email protected]>
Date:   Sat Aug 23 10:53:56 2025 -0600

    Merge branch 'master' into migrate_to_junit5

commit 6e3b929
Author: strangelookingnerd <[email protected]>
Date:   Thu Aug 14 11:50:43 2025 +0200

    Migrate tests to JUnit5

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

Author: MarkEWaite

.gitignore

@@ -5,7 +5,6 @@
 
 target/
 work/
-.@tmp/
 .vs/
 .vscode/
 

pom.xml

@@ -46,6 +46,7 @@
     <spotbugs.effort>Max</spotbugs.effort>
     <spotbugs.threshold>Low</spotbugs.threshold>
     <spotless.check.skip>false</spotless.check.skip>
+    <ban-junit4-imports.skip>false</ban-junit4-imports.skip>
   </properties>
 
   <dependencyManagement>
@@ -206,11 +207,6 @@
       <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>
@@ -238,7 +234,7 @@
     </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
+      <artifactId>mockito-junit-jupiter</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
@@ -247,12 +243,6 @@
       <version>3.4</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.testcontainers</groupId>
-      <artifactId>testcontainers</artifactId>
-      <version>1.21.3</version>
-      <scope>test</scope>
-    </dependency>
   </dependencies>
 
   <repositories>

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.mkdirs()) {
+            throw new IOException("Couldn't create folders " + result);
+        }
+        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";