Refactor tests and improve documentation

- Extracted common URL building logic into helper method
- Improved code maintainability by reducing duplication
- Clarified documentation for customURLPath parameter

Co-authored-by: chernser <[email protected]>

Author: Copilot

client-v2/src/main/java/com/clickhouse/client/api/Client.java

@@ -1052,8 +1052,9 @@ public Builder sslSocketSNI(String sni) {
          * Sets a custom URL path to be appended to the base URL for routing requests.
          * This is useful when multiple database instances are behind a load balancer and routing
          * is configured by path. For example: "/sales/db" or "/app/db".
+         * The path will be appended to the base endpoint URL as-is.
          *
-         * @param path - custom URL path (should start with "/")
+         * @param path - custom URL path (e.g., "/sales/db")
          * @return this builder instance
          */
         public Builder customURLPath(String path) {

client-v2/src/test/java/com/clickhouse/client/api/CustomURLPathTest.java

@@ -17,30 +17,35 @@
  */
 public class CustomURLPathTest {
 
-    @Test(groups = {"unit"})
-    public void testCustomURLPathConfiguration() {
-        String customPath = "/sales/db";
-        
-        // Simulate the URL building logic from HttpAPIClientHelper
-        String baseURL = "http://localhost:8123";
+    /**
+     * Helper method to build URI with custom path, simulating the logic from HttpAPIClientHelper.
+     */
+    private URI buildURIWithCustomPath(String baseURL, String customPath) throws URISyntaxException {
         Map<String, Object> requestConfig = new HashMap<>();
-        requestConfig.put(ClientConfigProperties.CUSTOM_URL_PATH.getKey(), customPath);
+        if (customPath != null) {
+            requestConfig.put(ClientConfigProperties.CUSTOM_URL_PATH.getKey(), customPath);
+        }
 
-        try {
-            URIBuilder uriBuilder = new URIBuilder(baseURL);
-            
-            // Add custom URL path if configured
-            String configuredPath = (String) requestConfig.get(ClientConfigProperties.CUSTOM_URL_PATH.getKey());
-            if (configuredPath != null && !configuredPath.isEmpty()) {
-                String existingPath = uriBuilder.getPath();
-                if (existingPath == null || existingPath.isEmpty() || existingPath.equals("/")) {
-                    uriBuilder.setPath(configuredPath);
-                } else {
-                    uriBuilder.setPath(existingPath + configuredPath);
-                }
+        URIBuilder uriBuilder = new URIBuilder(baseURL);
+        
+        // Add custom URL path if configured
+        String configuredPath = (String) requestConfig.get(ClientConfigProperties.CUSTOM_URL_PATH.getKey());
+        if (configuredPath != null && !configuredPath.isEmpty()) {
+            String existingPath = uriBuilder.getPath();
+            if (existingPath == null || existingPath.isEmpty() || existingPath.equals("/")) {
+                uriBuilder.setPath(configuredPath);
+            } else {
+                uriBuilder.setPath(existingPath + configuredPath);
             }
-            
-            URI uri = uriBuilder.normalizeSyntax().build();
+        }
+        
+        return uriBuilder.normalizeSyntax().build();
+    }
+
+    @Test(groups = {"unit"})
+    public void testCustomURLPathConfiguration() {
+        try {
+            URI uri = buildURIWithCustomPath("http://localhost:8123", "/sales/db");
 
             assertEquals(uri.toString(), "http://localhost:8123/sales/db");
             assertEquals(uri.getPath(), "/sales/db");
@@ -51,28 +56,8 @@ public void testCustomURLPathConfiguration() {
 
     @Test(groups = {"unit"})
     public void testCustomURLPathWithExistingPath() {
-        String customPath = "/app/db";
-        
-        // Test with base URL that already has a path
-        String baseURL = "http://localhost:8123/api";
-        Map<String, Object> requestConfig = new HashMap<>();
-        requestConfig.put(ClientConfigProperties.CUSTOM_URL_PATH.getKey(), customPath);
-        
         try {
-            URIBuilder uriBuilder = new URIBuilder(baseURL);
-            
-            // Add custom URL path if configured
-            String configuredPath = (String) requestConfig.get(ClientConfigProperties.CUSTOM_URL_PATH.getKey());
-            if (configuredPath != null && !configuredPath.isEmpty()) {
-                String existingPath = uriBuilder.getPath();
-                if (existingPath == null || existingPath.isEmpty() || existingPath.equals("/")) {
-                    uriBuilder.setPath(configuredPath);
-                } else {
-                    uriBuilder.setPath(existingPath + configuredPath);
-                }
-            }
-            
-            URI uri = uriBuilder.normalizeSyntax().build();
+            URI uri = buildURIWithCustomPath("http://localhost:8123/api", "/app/db");
 
             assertEquals(uri.toString(), "http://localhost:8123/api/app/db");
             assertEquals(uri.getPath(), "/api/app/db");
@@ -83,26 +68,8 @@ public void testCustomURLPathWithExistingPath() {
 
     @Test(groups = {"unit"})
     public void testEmptyCustomURLPath() {
-        // Test with empty custom path
-        String baseURL = "http://localhost:8123";
-        Map<String, Object> requestConfig = new HashMap<>();
-        requestConfig.put(ClientConfigProperties.CUSTOM_URL_PATH.getKey(), "");
-        
         try {
-            URIBuilder uriBuilder = new URIBuilder(baseURL);
-            
-            // Add custom URL path if configured
-            String configuredPath = (String) requestConfig.get(ClientConfigProperties.CUSTOM_URL_PATH.getKey());
-            if (configuredPath != null && !configuredPath.isEmpty()) {
-                String existingPath = uriBuilder.getPath();
-                if (existingPath == null || existingPath.isEmpty() || existingPath.equals("/")) {
-                    uriBuilder.setPath(configuredPath);
-                } else {
-                    uriBuilder.setPath(existingPath + configuredPath);
-                }
-            }
-            
-            URI uri = uriBuilder.normalizeSyntax().build();
+            URI uri = buildURIWithCustomPath("http://localhost:8123", "");
 
             // Empty path should not modify the URL
             assertEquals(uri.toString(), "http://localhost:8123");
@@ -113,25 +80,8 @@ public void testEmptyCustomURLPath() {
 
     @Test(groups = {"unit"})
     public void testNoCustomURLPath() {
-        // Test without custom path configured
-        String baseURL = "http://localhost:8123";
-        Map<String, Object> requestConfig = new HashMap<>();
-        
         try {
-            URIBuilder uriBuilder = new URIBuilder(baseURL);
-            
-            // Add custom URL path if configured
-            String configuredPath = (String) requestConfig.get(ClientConfigProperties.CUSTOM_URL_PATH.getKey());
-            if (configuredPath != null && !configuredPath.isEmpty()) {
-                String existingPath = uriBuilder.getPath();
-                if (existingPath == null || existingPath.isEmpty() || existingPath.equals("/")) {
-                    uriBuilder.setPath(configuredPath);
-                } else {
-                    uriBuilder.setPath(existingPath + configuredPath);
-                }
-            }
-            
-            URI uri = uriBuilder.normalizeSyntax().build();
+            URI uri = buildURIWithCustomPath("http://localhost:8123", null);
 
             // No custom path should keep URL unchanged
             assertEquals(uri.toString(), "http://localhost:8123");