Task: warn unsupported auth flows

src/Kiota.Builder/KiotaBuilder.cs

@@ -243,7 +243,7 @@ public async Task<bool> GeneratePluginAsync(CancellationToken cancellationToken)
                 throw new InvalidOperationException("The OpenAPI document and the URL tree must be loaded before generating the plugins");
             // generate plugin
             sw.Start();
-            var pluginsService = new PluginsGenerationService(openApiDocument, openApiTree, config, Directory.GetCurrentDirectory());
+            var pluginsService = new PluginsGenerationService(openApiDocument, openApiTree, config, Directory.GetCurrentDirectory(), logger);
             await pluginsService.GenerateManifestAsync(cancellationToken).ConfigureAwait(false);
             StopLogAndReset(sw, $"step {++stepId} - generate plugin - took");
             return stepId;

src/Kiota.Builder/Plugins/PluginsGenerationService.cs

@@ -9,6 +9,7 @@
 using Kiota.Builder.Configuration;
 using Kiota.Builder.Extensions;
 using Kiota.Builder.OpenApiExtensions;
+using Microsoft.Extensions.Logging;
 using Microsoft.OpenApi.ApiManifest;
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Services;
@@ -23,9 +24,10 @@ public partial class PluginsGenerationService
     private readonly OpenApiUrlTreeNode TreeNode;
     private readonly GenerationConfiguration Configuration;
     private readonly string WorkingDirectory;
+    private readonly ILogger<KiotaBuilder> Logger;
 
     public PluginsGenerationService(OpenApiDocument document, OpenApiUrlTreeNode openApiUrlTreeNode,
-        GenerationConfiguration configuration, string workingDirectory)
+        GenerationConfiguration configuration, string workingDirectory, ILogger<KiotaBuilder> logger)
     {
         ArgumentNullException.ThrowIfNull(document);
         ArgumentNullException.ThrowIfNull(openApiUrlTreeNode);
@@ -35,6 +37,7 @@ public PluginsGenerationService(OpenApiDocument document, OpenApiUrlTreeNode ope
         TreeNode = openApiUrlTreeNode;
         Configuration = configuration;
         WorkingDirectory = workingDirectory;
+        Logger = logger;
     }
 
     private static readonly OpenAPIRuntimeComparer _openAPIRuntimeComparer = new();
@@ -258,7 +261,7 @@ private OpenApiDocument GetDocumentWithTrimmedComponentsAndResponses(OpenApiDocu
 
     private PluginManifestDocument GetManifestDocument(string openApiDocumentPath)
     {
-        var (runtimes, functions, conversationStarters) = GetRuntimesFunctionsAndConversationStartersFromTree(OAIDocument, Configuration.PluginAuthInformation, TreeNode, openApiDocumentPath);
+        var (runtimes, functions, conversationStarters) = GetRuntimesFunctionsAndConversationStartersFromTree(OAIDocument, Configuration.PluginAuthInformation, TreeNode, openApiDocumentPath, Logger);
         var descriptionForHuman = OAIDocument.Info?.Description is string d && !string.IsNullOrEmpty(d) ? d : $"Description for {OAIDocument.Info?.Title}";
         var manifestInfo = ExtractInfoFromDocument(OAIDocument.Info);
         var pluginManifestDocument = new PluginManifestDocument
@@ -338,7 +341,7 @@ private sealed record OpenApiManifestInfo(
         string ContactEmail = DefaultContactEmail);
 
     private static (OpenApiRuntime[], Function[], ConversationStarter[]) GetRuntimesFunctionsAndConversationStartersFromTree(OpenApiDocument document, PluginAuthConfiguration? authInformation, OpenApiUrlTreeNode currentNode,
-        string openApiDocumentPath)
+        string openApiDocumentPath, ILogger<KiotaBuilder> logger)
     {
         var runtimes = new List<OpenApiRuntime>();
         var functions = new List<Function>();
@@ -348,10 +351,21 @@ private static (OpenApiRuntime[], Function[], ConversationStarter[]) GetRuntimes
         {
             foreach (var operation in pathItem.Operations.Values.Where(static x => !string.IsNullOrEmpty(x.OperationId)))
             {
+                var auth = configAuth;
+                try
+                {
+                    auth = configAuth ?? GetAuth(operation.Security ?? document.SecurityRequirements);
+                }
+                catch (UnsupportedSecuritySchemeException e)
+                {
+                    auth = new AnonymousAuth();
+                    logger.LogWarning("Authentication warning: {OperationId} - {Message}", operation.OperationId, e.Message);
+                }
+
                 runtimes.Add(new OpenApiRuntime
                 {
                     // Configuration overrides document information
-                    Auth = configAuth ?? GetAuth(operation.Security ?? document.SecurityRequirements),
+                    Auth = auth,
                     Spec = new OpenApiRuntimeSpec { Url = openApiDocumentPath },
                     RunForFunctions = [operation.OperationId]
                 });
@@ -376,7 +390,7 @@ private static (OpenApiRuntime[], Function[], ConversationStarter[]) GetRuntimes
 
         foreach (var node in currentNode.Children)
         {
-            var (childRuntimes, childFunctions, childConversationStarters) = GetRuntimesFunctionsAndConversationStartersFromTree(document, authInformation, node.Value, openApiDocumentPath);
+            var (childRuntimes, childFunctions, childConversationStarters) = GetRuntimesFunctionsAndConversationStartersFromTree(document, authInformation, node.Value, openApiDocumentPath, logger);
             runtimes.AddRange(childRuntimes);
             functions.AddRange(childFunctions);
             conversationStarters.AddRange(childConversationStarters);
@@ -391,7 +405,7 @@ private static Auth GetAuth(IList<OpenApiSecurityRequirement> securityRequiremen
         const string tooManySchemesError = "Multiple security requirements are not supported. Operations can only list one security requirement.";
         if (securityRequirements.Count > 1 || securityRequirements.FirstOrDefault()?.Keys.Count > 1)
         {
-            throw new InvalidOperationException(tooManySchemesError);
+            throw new UnsupportedSecuritySchemeException(tooManySchemesError);
         }
         var security = securityRequirements.FirstOrDefault();
         var opSecurity = security?.Keys.FirstOrDefault();