fix(hivemq): ignore all array descriptors when collecting subclasses

modules/hivemq/src/main/java/org/testcontainers/hivemq/HiveMQExtension.java

@@ -152,11 +152,13 @@ private void putSubclassesIntoJar(
             for (final String subClassName : subClassNames) {
                 final String className = subClassName.replaceAll("/", ".");
 
-                if (!className.startsWith("[L")) {
+                // Array descriptors from the constant pool (e.g. "[B", "[Lcom.example.Foo;",
+                // "[[Ljava.lang.String;") do not name classes that can be added to the archive.
+                if (!className.startsWith("[")) {
                     LOGGER.debug("Trying to package subclass '{}' into extension '{}'.", className, extensionId);
                     javaArchive.addClass(className);
                 } else {
-                    LOGGER.debug("Class '{}' will be ignored.", className);
+                    LOGGER.debug("Array descriptor '{}' will be ignored.", className);
                 }
             }
         }

modules/hivemq/src/test/java/org/testcontainers/hivemq/HiveMQExtensionArrayDescriptorTest.java

@@ -0,0 +1,63 @@
+package org.testcontainers.hivemq;
+
+import com.hivemq.extension.sdk.api.ExtensionMain;
+import com.hivemq.extension.sdk.api.parameter.ExtensionStartInput;
+import com.hivemq.extension.sdk.api.parameter.ExtensionStartOutput;
+import com.hivemq.extension.sdk.api.parameter.ExtensionStopInput;
+import com.hivemq.extension.sdk.api.parameter.ExtensionStopOutput;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HiveMQExtensionArrayDescriptorTest {
+
+    @Test
+    void createExtension_ignoresArrayDescriptorsInConstantPool() throws Exception {
+        final HiveMQExtension extension = HiveMQExtension
+            .builder()
+            .id("my-extension")
+            .name("My Extension")
+            .version("1.0.0")
+            .mainClass(NoopExtension.class)
+            .addAdditionalClass(ArrayHolder.class)
+            .build();
+
+        final File extensionDir = extension.createExtension(extension);
+
+        assertThat(new File(extensionDir, "extension.jar")).exists();
+    }
+
+    public static class NoopExtension implements ExtensionMain {
+
+        @Override
+        public void extensionStart(
+            final ExtensionStartInput extensionStartInput,
+            final ExtensionStartOutput extensionStartOutput
+        ) {}
+
+        @Override
+        public void extensionStop(
+            final ExtensionStopInput extensionStopInput,
+            final ExtensionStopOutput extensionStopOutput
+        ) {}
+    }
+
+    /**
+     * Referencing array classes forces their descriptors ([B, [J, [[Ljava/lang/String;) into the
+     * constant pool of this class, which previously made {@link HiveMQExtension#createExtension} fail
+     * with a {@link java.util.regex.PatternSyntaxException}.
+     */
+    public static class ArrayHolder {
+
+        @SuppressWarnings("unused")
+        private static final Class<?> BYTE_ARRAY_CLASS = byte[].class;
+
+        @SuppressWarnings("unused")
+        private static final Class<?> LONG_ARRAY_CLASS = long[].class;
+
+        @SuppressWarnings("unused")
+        private static final Class<?> MULTIDIMENSIONAL_OBJECT_ARRAY_CLASS = String[][].class;
+    }
+}