Validate openapi before generation

src/Kiota.Builder/Plugins/PluginsGenerationService.cs

@@ -44,27 +44,11 @@ public PluginsGenerationService(OpenApiDocument document, OpenApiUrlTreeNode ope
     private const string DescriptionPathSuffix = "openapi.yml";
     public async Task GenerateManifestAsync(CancellationToken cancellationToken = default)
     {
-
-        //1. validate openapi file
-        var ruleSet = new Microsoft.OpenApi.Validations.ValidationRuleSet
-        {
-            OpenApiServerUrlRule.ServerUrlMustBeHttps,
-            OpenApiCombinedAuthFlowRule.PathsCanOnlyHaveOneSecuritySchemePerOperation(OAIDocument.SecurityRequirements),
-            OpenApiRequestBodySchemaRule.RequestBodySchemaObjectsMustNeverBeNested,
-            OpenApiApiKeyBearerRule.ApiKeyNotSupportedOnlyBearerPlusHttp(OAIDocument.SecurityRequirements)
-        };
-        var errors = OAIDocument.Validate(ruleSet)?.ToArray();
-        if (errors != null && errors.Length != 0)
-        {
-            var message = string.Join(Environment.NewLine, errors.Select(e => $"{e.Pointer}: {e.Message}"));
-            throw new InvalidOperationException($"OpenApi document validation failed with errors: {message}");
-        }
-
-        // 2. cleanup any namings to be used later on.
+        // 1. cleanup any namings to be used later on.
         Configuration.ClientClassName =
             PluginNameCleanupRegex().Replace(Configuration.ClientClassName, string.Empty); //drop any special characters
 
-        // 3. write the OpenApi description
+        // 2. write the OpenApi description
         var descriptionRelativePath = $"{Configuration.ClientClassName.ToLowerInvariant()}-{DescriptionPathSuffix}";
         var descriptionFullPath = Path.Combine(Configuration.OutputPath, descriptionRelativePath);
         var directory = Path.GetDirectoryName(descriptionFullPath);
@@ -80,6 +64,21 @@ public async Task GenerateManifestAsync(CancellationToken cancellationToken = de
         trimmedPluginDocument.SerializeAsV3(descriptionWriter);
         descriptionWriter.Flush();
 
+        //3. validate openapi file
+        var ruleSet = new Microsoft.OpenApi.Validations.ValidationRuleSet
+        {
+            OpenApiServerUrlRule.ServerUrlMustBeHttps,
+            OpenApiCombinedAuthFlowRule.PathsCanOnlyHaveOneSecuritySchemePerOperation(OAIDocument.SecurityRequirements),
+            OpenApiRequestBodySchemaRule.RequestBodySchemaObjectsMustNeverBeNested,
+            OpenApiApiKeyBearerRule.ApiKeyNotSupportedOnlyBearerPlusHttp(OAIDocument.SecurityRequirements)
+        };
+        var errors = OAIDocument.Validate(ruleSet)?.ToArray();
+        if (errors != null && errors.Length != 0)
+        {
+            var message = string.Join(Environment.NewLine, errors.Select(e => $"{e.Pointer}: {e.Message}"));
+            throw new InvalidOperationException($"OpenApi document validation failed with errors: {message}");
+        }
+
         // 4. write the plugins
 
         foreach (var pluginType in Configuration.PluginTypes)