Add test for CompressionConfig and fix bugs.

Motivation:

CompressionConfig is lacking correctness tests and has a couple of bug to fix.

Changes:

More toroughly test CompressionConfig and fix the brotli bug.

Author: vietj

vertx-core/src/main/java/io/vertx/core/http/CompressionConfig.java

@@ -286,6 +286,6 @@ public CompressionConfig addBrotli() {
    */
   @GenIgnore
   public CompressionConfig addBrotli(int quality) {
-    return addCompressor(StandardCompressionOptions.brotli(quality, 4, BrotliMode.TEXT));
+    return addCompressor(StandardCompressionOptions.brotli(quality, 22, BrotliMode.TEXT));
   }
 }

vertx-core/src/test/java/io/vertx/tests/http/compression/HttpCompressionConfigTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2011-2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+package io.vertx.tests.http.compression;
+
+import io.netty.handler.codec.compression.*;
+import io.vertx.core.http.CompressionConfig;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class HttpCompressionConfigTest {
+
+  private CompressionConfig cfg;
+
+  @Before
+  public void before() {
+    cfg = new CompressionConfig();
+  }
+
+  @Test
+  public void testBrotli() {
+    cfg.addBrotli();
+    assertEquals(StandardCompressionOptions.brotli());
+    cfg.addBrotli(10);
+    assertEquals(StandardCompressionOptions.brotli(10, 22, BrotliMode.TEXT));
+  }
+
+  @Test
+  public void testDeflate() {
+    DeflateOptions def = StandardCompressionOptions.deflate();
+    cfg.addDeflate();
+    assertEquals(def);
+    cfg.addDeflate(8);
+    assertEquals(StandardCompressionOptions.deflate(8, def.windowBits(), def.memLevel()));
+    cfg.addDeflate(8, 10, 7);
+    assertEquals(StandardCompressionOptions.deflate(8, 10, 7));
+  }
+
+  @Test
+  public void testGzip() {
+    GzipOptions def = StandardCompressionOptions.gzip();
+    cfg.addGzip();
+    assertEquals(StandardCompressionOptions.gzip());
+    cfg.addGzip(8);
+    assertEquals(StandardCompressionOptions.gzip(8, def.windowBits(), def.memLevel()));
+    cfg.addGzip(8, 10, 7);
+    assertEquals(StandardCompressionOptions.gzip(8, 10, 7));
+  }
+
+  @Test
+  public void testSnappy() {
+    cfg.addSnappy();
+    assertEquals(StandardCompressionOptions.snappy());
+  }
+
+  @Test
+  public void testZstd() {
+    ZstdOptions def = StandardCompressionOptions.zstd();
+    cfg.addZstd();
+    assertEquals(def);
+    cfg.addZstd(10);
+    assertEquals(StandardCompressionOptions.zstd(10, def.blockSize(), def.maxEncodeSize()));
+    cfg.addZstd(10, 11, 12);
+    assertEquals(StandardCompressionOptions.zstd(10, 11, 12));
+  }
+
+  private void assertEquals(BrotliOptions expected) {
+    BrotliOptions actual = (BrotliOptions) cfg.getCompressors().get(0);
+    Assert.assertEquals(expected.parameters().lgwin(), actual.parameters().lgwin());
+    Assert.assertEquals(expected.parameters().mode(), actual.parameters().mode());
+    Assert.assertEquals(expected.parameters().quality(), actual.parameters().quality());
+  }
+
+  private void assertEquals(DeflateOptions expected) {
+    DeflateOptions actual = (DeflateOptions) cfg.getCompressors().get(0);
+    Assert.assertEquals(expected.compressionLevel(), actual.compressionLevel());
+    Assert.assertEquals(expected.memLevel(), actual.memLevel());
+    Assert.assertEquals(expected.windowBits(), actual.windowBits());
+  }
+
+  private void assertEquals(GzipOptions expected) {
+    GzipOptions actual = (GzipOptions) cfg.getCompressors().get(0);
+    Assert.assertEquals(expected.compressionLevel(), actual.compressionLevel());
+    Assert.assertEquals(expected.memLevel(), actual.memLevel());
+    Assert.assertEquals(expected.windowBits(), actual.windowBits());
+  }
+
+  private void assertEquals(ZstdOptions expected) {
+    ZstdOptions actual = (ZstdOptions) cfg.getCompressors().get(0);
+    Assert.assertEquals(expected.compressionLevel(), actual.compressionLevel());
+    Assert.assertEquals(expected.maxEncodeSize(), actual.maxEncodeSize());
+    Assert.assertEquals(expected.blockSize(), actual.blockSize());
+  }
+
+  private void assertEquals(SnappyOptions expected) {
+    // No config at the moment
+  }
+}

vertx-core/src/test/java/module-info.java

@@ -39,6 +39,7 @@
   requires io.netty.codec.dns;
   requires static io.netty.tcnative.classes.openssl;
   requires jdk.management;
+  requires static com.aayushatharva.brotli4j;
 
   provides VerticleFactory with ClasspathVerticleFactory, io.vertx.tests.vertx.AccessEventBusFromInitVerticleFactory;