Add IsStdioMode property and update plugin URL validation logic. Closes #1519 (#1523)

Co-authored-by: Garry Trinder <garry@trinder365.co.uk>

Author: waldekmastykarz

DevProxy/Commands/DevProxyConfigOptions.cs

@@ -21,6 +21,7 @@ public string? ConfigFile
     public int? ApiPort => _parseResult?.GetValueOrDefault<int?>(DevProxyCommand.ApiPortOptionName);
     public bool Discover => _parseResult?.GetValueOrDefault<bool?>(DevProxyCommand.DiscoverOptionName) ?? false;
     public string? IPAddress => _parseResult?.GetValueOrDefault<string?>(DevProxyCommand.IpAddressOptionName);
+    public bool IsStdioMode => _parseResult?.CommandResult.Command.Name == "stdio";
     public LogFor? LogFor => _parseResult?.GetValueOrDefault<LogFor?>(DevProxyCommand.LogForOptionName);
     public LogLevel? LogLevel => _parseResult?.GetValueOrDefault<LogLevel?>(DevProxyCommand.LogLevelOptionName);
 

DevProxy/Plugins/PluginServiceExtensions.cs

@@ -125,7 +125,8 @@ public static IServiceCollection AddPlugins(
                     assembly,
                     configuration,
                     services,
-                    logger);
+                    logger,
+                    options.IsStdioMode);
             }
             catch (Exception ex)
             {
@@ -149,14 +150,9 @@ private static void RegisterPlugin(
         Assembly assembly,
         IConfiguration configuration,
         IServiceCollection services,
-        ILogger logger)
+        ILogger logger,
+        bool isStdioMode)
     {
-        if (urlsToWatch.Count == 0)
-        {
-            logger.LogError("Plugin {PluginName} must have at least one URL to watch. Please add a URL to watch in the configuration file or use the --urls-to-watch option.", pluginRef.Name);
-            return;
-        }
-
         var pluginType = assembly.GetTypes()
             .FirstOrDefault(t => t.Name == pluginRef.Name && typeof(IPlugin).IsAssignableFrom(t));
         if (pluginType is null)
@@ -165,6 +161,14 @@ private static void RegisterPlugin(
             return;
         }
 
+        // In stdio mode, plugins don't need URLs to watch because they
+        // communicate through STDIO (JSON-RPC) rather than HTTP
+        if (urlsToWatch.Count == 0 && !isStdioMode)
+        {
+            logger.LogError("Plugin {PluginName} must have at least one URL to watch. Please add a URL to watch in the configuration file or use the --urls-to-watch option.", pluginRef.Name);
+            return;
+        }
+
         var isConfigurable = IsConfigurablePlugin(pluginType, out var configType);
 
         if (!isConfigurable || configType is null)