Try adding tests

Author: EmandM

com.unity.netcode.gameobjects/Runtime/HelpURL.cs

@@ -0,0 +1,22 @@
+namespace Unity.Netcode.Runtime
+{
+    internal static class HelpUrls
+    {
+        private const string k_BaseUrl = "https://docs.unity3d.com/Packages/com.unity.netcode.gameobjects@latest/?subfolder=/";
+        private const string k_BaseManualUrl = k_BaseUrl + "manual/";
+        private const string k_BaseApiUrl = k_BaseUrl + "api/Unity.Netcode";
+
+        public const string NetworkManager = k_BaseManualUrl + "components/core/networkmanager.html";
+        public const string NetworkObject = k_BaseManualUrl + "components/core/networkobject.html";
+        public const string NetworkAnimator = k_BaseManualUrl + "components/helper/networkanimator.html";
+        public const string NetworkRigidbody = k_BaseManualUrl + "advanced-topics/physics.html#networkrigidbody";
+        public const string NetworkRigidbody2D = k_BaseManualUrl + "advanced-topics/physics.html#networkrigidbody2d";
+        public const string RigidbodyContactEventManager = k_BaseApiUrl + ".Components.RigidbodyContactEventManager.html";
+        public const string NetworkTransform = k_BaseManualUrl + "components/helper/networktransform.html";
+        public const string AnticipatedNetworkTransform = k_BaseManualUrl + "advanced-topics/client-anticipation.html";
+        public const string UnityTransport = k_BaseApiUrl + ".Transports.UTP.UnityTransport.html";
+        public const string SecretsLoaderHelper = k_BaseManualUrl + ".Transports.UTP.SecretsLoaderHelper.html";
+        public const string SinglePlayerTransport = k_BaseApiUrl + ".Transports.SinglePlayer.SinglePlayerTransport.html";
+        public const string NotValid = k_BaseApiUrl + ".SomeObject.NotValid.html";
+    }
+}

com.unity.netcode.gameobjects/Runtime/HelpUrls.cs

@@ -0,0 +1,85 @@
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+using NUnit.Framework;
+using Unity.Netcode.Runtime;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Unity.Netcode.RuntimeTests
+{
+    internal class HelpUrlTests
+    {
+        private static readonly HttpClient k_HttpClient = new HttpClient();
+
+        [UnityTest]
+        public IEnumerator ValidateUrlsAreValid()
+        {
+            var names = new List<string>();
+            var allUrls = new List<string>();
+
+            foreach (var constant in typeof(HelpUrls).GetFields())
+            {
+                if (constant.IsLiteral && !constant.IsInitOnly)
+                {
+                    names.Add(constant.Name);
+                    allUrls.Add((string)constant.GetValue(null));
+                }
+            }
+            Debug.Log($"Found {allUrls.Count} URLs");
+
+            var tasks = new List<Task<bool>>();
+            foreach (var url in allUrls)
+            {
+                tasks.Add(IsRemoteFileAvailable(url));
+            }
+
+            while (tasks.Any(task => !task.IsCompleted))
+            {
+                yield return new WaitForSeconds(0.01f);
+            }
+
+            for (int i = 0; i < allUrls.Count; i++)
+            {
+                Assert.IsTrue(tasks[i].Result, $"HelpUrls.{names[i]} is an invalid path!");
+            }
+        }
+
+        /// <summary>
+        /// Checks if a remote file at the <paramref name="url"/> exists, and if access is not restricted.
+        /// </summary>
+        /// <param name="url">URL to a remote file.</param>
+        /// <returns>True if the file at the <paramref name="url"/> is able to be downloaded, false if the file does not exist, or if the file is restricted.</returns>
+        private static async Task<bool> IsRemoteFileAvailable(string url)
+        {
+            //Checking if URI is well formed is optional
+            var uri = new Uri(url);
+            if (!uri.IsWellFormedOriginalString())
+            {
+                Debug.LogError($"URL {url} is not well formed");
+                return false;
+            }
+
+            try
+            {
+                using var request = new HttpRequestMessage(HttpMethod.Head, uri);
+                using var response = await k_HttpClient.SendAsync(request);
+
+                var exists = response.IsSuccessStatusCode && response.Content.Headers.ContentLength > 0;
+                Debug.Log($"url {url} returned status code {response.StatusCode}");
+                return exists;
+            }
+            catch
+            {
+                Debug.LogError($"URL {url} request failed");
+                return false;
+            }
+        }
+
+    }
+}

com.unity.netcode.gameobjects/Runtime/HelpURL.cs.meta renamed to com.unity.netcode.gameobjects/Runtime/HelpUrls.cs.meta

@@ -197,7 +197,7 @@ internal static string GetCMBServiceEnvironentVariable()
 #if USE_CMB_SERVICE
             return "true";
 #else
-            return Environment.GetEnvironmentVariable("USE_CMB_SERVICE") ?? "false";
+            return Environment.GetEnvironmentVariable("USE_CMB_SERVICE") ?? "true";
 #endif
         }