Polishing.

Reformat code. Split tests into positives and negatives.

[#656]

Author: mp911de

src/main/java/io/r2dbc/postgresql/PostgresqlConnectionConfiguration.java

@@ -1203,7 +1203,6 @@ private static void appendSniHost(SSLParameters sslParameters, String hostString
             sslParameters.setServerNames(serverNames);
         }
 
-
         private Supplier<SslContext> createSslProvider() {
             SslContextBuilder sslContextBuilder = SslContextBuilder.forClient();
             if (this.sslMode.verifyCertificate()) {

src/test/java/io/r2dbc/postgresql/client/SSLConfigTests.java

@@ -1,17 +1,40 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package io.r2dbc.postgresql.client;
 
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Unit tests for {@link SSLConfig}.
  */
 final class SSLConfigTests {
-    @Test
-    public void testValidSniHostname(){
-        assertThat(SSLConfig.isValidSniHostname("example.com")).isEqualTo(true);
-        assertThat(SSLConfig.isValidSniHostname("example://.com")).isEqualTo(false);
-        assertThat(SSLConfig.isValidSniHostname("example.com.")).isEqualTo(false);
+
+    @ParameterizedTest
+    @ValueSource(strings = {"example.com", "foo"})
+    public void shouldAcceptValidSniHostname(String hostname) {
+        assertThat(SSLConfig.isValidSniHostname(hostname)).isTrue();
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"example.com.", "example://.com"})
+    public void shouldRejectValidSniHostname(String hostname) {
+        assertThat(SSLConfig.isValidSniHostname(hostname)).isFalse();
     }
 }