Update src/Microsoft.OpenApi.Hidi/OpenApiService.cs

Co-authored-by: Irvine Sunday <[email protected]>

Author: danielmbaluka

src/Microsoft.OpenApi.Hidi/OpenApiService.cs

@@ -204,7 +204,7 @@ internal static void ValidateOpenApiDocument(string input)
 
         private static OpenApiFormat GetOpenApiFormat(string input)
         {
-            if (!input.StartsWith("http") && Path.GetExtension(input) == ".json")
+            return !input.StartsWith("http") && Path.GetExtension(input) == ".json" ? OpenApiFormat.Json : OpenApiFormat.Yaml;
             {
                 return OpenApiFormat.Json;
             }