Upgrade from JUnit 4 to JUnit Jupiter 6.0.3 (#1146)

- Replace junit:junit:4.13.2 with JUnit Jupiter/Platform 6.0.3 via BOM
- Migrate all test imports from org.junit to org.junit.jupiter.api
- Convert @Before/@after to @BeforeEach/@AfterEach
- Replace @rule TemporaryFolder with @tempdir
- Replace @test(timeout=) with @timeout annotation
- Default java_test_suite wrapper to runner="junit5" with auto-injected
  runtime deps for the Jupiter engine and platform

Author: aaylward

MODULE.bazel.lock

@@ -53,7 +53,11 @@ maven.install(
         "io.netty:netty-transport",
         "io.sentry:sentry-logback:8.34.1",
         "jakarta.annotation:jakarta.annotation-api:3.0.0",
-        "junit:junit:4.13.2",
+        "org.junit.jupiter:junit-jupiter-api",
+        "org.junit.jupiter:junit-jupiter-engine",
+        "org.junit.jupiter:junit-jupiter-params",
+        "org.junit.platform:junit-platform-launcher",
+        "org.junit.platform:junit-platform-reporting",
         "org.assertj:assertj-core:3.27.7",
         "org.eclipse.jetty:jetty-server:%s" % JETTY_VERSION,
         "org.eclipse.jetty.websocket:websocket-jetty-server:%s" % JETTY_VERSION,
@@ -66,9 +70,11 @@ maven.install(
         "io.micronaut.jaxrs:micronaut-jaxrs-bom:4.10.0",
         "io.micronaut.validation:micronaut-validation-bom:4.12.0",
         "com.fasterxml.jackson:jackson-bom:2.21.0",
+        "org.junit:junit-bom:6.0.3",
     ],
     generate_compat_repositories = True,
     known_contributing_modules = [
+        "",
         "moon-base",
         "protobuf",
     ],

bazel/java.MODULE.bazel

@@ -21,7 +21,28 @@ load("@rules_java//java:defs.bzl", _java_binary = "java_binary", _java_library =
 load("@rules_jvm_external//:defs.bzl", _artifact = "artifact")
 
 artifact = _artifact
-java_test_suite = _java_test_suite
+
+_JUNIT_RUNTIME_DEPS = [
+    _artifact("org.junit.jupiter:junit-jupiter-engine"),
+    _artifact("org.junit.platform:junit-platform-launcher"),
+    _artifact("org.junit.platform:junit-platform-reporting"),
+]
+
+def java_test_suite(runner = "junit5", runtime_deps = [], **kwargs):
+    """java_test_suite defaulting to JUnit 5 (Jupiter).
+
+    Automatically adds JUnit Jupiter engine and platform runtime deps.
+
+    Args:
+        runner: Test runner to use. Defaults to "junit5".
+        runtime_deps: Additional runtime dependencies.
+        **kwargs: Arguments passed to java_test_suite.
+    """
+    _java_test_suite(
+        runner = runner,
+        runtime_deps = runtime_deps + _JUNIT_RUNTIME_DEPS,
+        **kwargs
+    )
 
 _NULLAWAY_PLUGIN = "//bazel/rules:nullaway"
 

bazel/rules/java.bzl

@@ -102,7 +102,7 @@ java_test_suite(
         ":tools",
         "//domains/games/libs/chess_com_client",
         "//domains/platform/libs/json",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )

domains/games/apis/mcpserver/BUILD.bazel

@@ -10,7 +10,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class ChessComGamesToolTest {
 

domains/games/apis/mcpserver/src/test/java/com/muchq/games/mcpserver/tools/ChessComGamesToolTest.java

@@ -9,7 +9,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class ChessComPlayerToolTest {
 

domains/games/apis/mcpserver/src/test/java/com/muchq/games/mcpserver/tools/ChessComPlayerToolTest.java

@@ -7,7 +7,7 @@
 import com.muchq.platform.json.JsonUtils;
 import java.util.Map;
 import java.util.Optional;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class ChessComStatsToolTest {
 

domains/games/apis/mcpserver/src/test/java/com/muchq/games/mcpserver/tools/ChessComStatsToolTest.java

@@ -6,7 +6,7 @@
 import java.time.Instant;
 import java.time.ZoneId;
 import java.util.Map;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class ServerTimeToolTest {
   private static final Instant FIXED_INSTANT = Instant.parse("2024-01-15T10:30:45.123Z");

domains/games/apis/mcpserver/src/test/java/com/muchq/games/mcpserver/tools/ServerTimeToolTest.java

@@ -260,7 +260,7 @@ java_test_suite(
         ":engine",
         ":model",
         ":motifs",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -284,7 +284,7 @@ java_test_suite(
     deps = [
         ":model",
         ":motifs",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -299,7 +299,7 @@ java_test_suite(
         ":engine",
         ":model",
         ":motifs",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -310,7 +310,7 @@ java_test_suite(
     srcs = ["src/test/java/com/muchq/games/one_d4/queue/InMemoryIndexQueueTest.java"],
     deps = [
         ":queue",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -336,7 +336,7 @@ java_test_suite(
         "//domains/games/libs/chessql:compiler",
         "//domains/games/libs/chessql:parser",
         artifact("com.fasterxml.jackson.core:jackson-databind"),
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
         artifact("org.jdbi:jdbi3-core"),
     ],
@@ -361,7 +361,7 @@ java_test_suite(
         ":queue",
         "//domains/games/libs/chessql:compiler",
         "//domains/games/libs/chessql:parser",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -374,7 +374,7 @@ java_test_suite(
     ],
     deps = [
         ":module",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -395,7 +395,7 @@ java_test_suite(
         ":test_db",
         "//domains/games/libs/chessql:compiler",
         "//domains/games/libs/chessql:parser",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
         artifact("org.jdbi:jdbi3-core"),
     ],
@@ -453,7 +453,7 @@ java_test_suite(
         artifact("io.micronaut:micronaut-http-server-netty"),
         artifact("io.micronaut:micronaut-inject"),
         artifact("io.micronaut:micronaut-runtime"),
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )
@@ -481,7 +481,7 @@ java_test_suite(
         "//domains/games/libs/chessql:compiler",
         "//domains/games/libs/chessql:parser",
         artifact("com.fasterxml.jackson.core:jackson-databind"),
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
         artifact("org.jdbi:jdbi3-core"),
     ],
@@ -500,7 +500,7 @@ java_test_suite(
         ":test_db",
         "//domains/games/libs/chessql:compiler",
         "//domains/games/libs/chessql:parser",
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
         artifact("org.jdbi:jdbi3-core"),
     ],
@@ -522,7 +522,7 @@ java_test_suite(
         artifact("io.micronaut:micronaut-http-server-netty"),
         artifact("io.micronaut:micronaut-inject"),
         artifact("io.micronaut:micronaut-runtime"),
-        artifact("junit:junit"),
+        artifact("org.junit.jupiter:junit-jupiter-api"),
         artifact("org.assertj:assertj-core"),
     ],
 )

domains/games/apis/one_d4/BUILD.bazel

@@ -7,13 +7,12 @@
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-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 IndexerModuleTest {
 
-  @Rule public TemporaryFolder tmp = new TemporaryFolder();
+  @TempDir Path tmp;
 
   @Test
   public void readJdbcUrl_returnsEnvVar_whenSet() {
@@ -35,7 +34,7 @@ public void readJdbcUrl_ignoresBlankEnvVar() {
 
   @Test
   public void readJdbcUrl_ignoresNullEnvVar_andReadsFile() throws IOException {
-    Path configFile = tmp.newFile("db_config").toPath();
+    Path configFile = Files.createFile(tmp.resolve("db_config"));
     Files.writeString(configFile, "jdbc:postgresql://file-host:5432/chess\n");
 
     String result = IndexerModule.readJdbcUrl(null, configFile);
@@ -50,7 +49,7 @@ public void readJdbcUrl_returnsDefault_whenFileIsMissing() {
 
   @Test
   public void readJdbcUrl_returnsDefault_whenFileIsEmpty() throws IOException {
-    Path configFile = tmp.newFile("db_config_empty").toPath();
+    Path configFile = Files.createFile(tmp.resolve("db_config_empty"));
     Files.writeString(configFile, "   ");
 
     String result = IndexerModule.readJdbcUrl(null, configFile);
@@ -59,7 +58,7 @@ public void readJdbcUrl_returnsDefault_whenFileIsEmpty() throws IOException {
 
   @Test
   public void readJdbcUrl_envVarTakesPrecedenceOverFile() throws IOException {
-    Path configFile = tmp.newFile("db_config_precedence").toPath();
+    Path configFile = Files.createFile(tmp.resolve("db_config_precedence"));
     Files.writeString(configFile, "jdbc:postgresql://file-host/db");
 
     String result = IndexerModule.readJdbcUrl("jdbc:postgresql://env-host/db", configFile);
@@ -69,7 +68,7 @@ public void readJdbcUrl_envVarTakesPrecedenceOverFile() throws IOException {
   @Test
   public void readJdbcUrl_throwsUncheckedIOException_onNonFileNotFoundIOError() {
     // A directory path will cause an IOException (not NoSuchFileException) when read as a file
-    Path dirPath = tmp.getRoot().toPath();
+    Path dirPath = tmp;
 
     assertThatThrownBy(() -> IndexerModule.readJdbcUrl(null, dirPath))
         .isInstanceOf(UncheckedIOException.class)
@@ -104,6 +103,6 @@ public void parseThreads_respectsValidValue() {
   }
 
   private Path missingPath() {
-    return tmp.getRoot().toPath().resolve("nonexistent_db_config");
+    return tmp.resolve("nonexistent_db_config");
   }
 }