Add default username for OAuth2 password flow.

src/Swashbuckle.AspNetCore.SwaggerUI/SwaggerUIOptions.cs

@@ -179,6 +179,11 @@ public enum SubmitMethod
 
     public class OAuthConfigObject
     {
+        /// <summary>
+        /// Default username for OAuth2 password flow.
+        /// </summary>
+        public string Username { get; set; } = null;
+
         /// <summary>
         /// Default clientId
         /// </summary>

src/Swashbuckle.AspNetCore.SwaggerUI/SwaggerUIOptionsExtensions.cs

@@ -43,7 +43,7 @@ public static void InjectJavascript(this SwaggerUIOptions options, string path,
         public static void SwaggerEndpoint(this SwaggerUIOptions options, string url, string name)
         {
             var urls = new List<UrlDescriptor>(options.ConfigObject.Urls ?? Enumerable.Empty<UrlDescriptor>());
-            urls.Add(new UrlDescriptor { Url = url, Name = name} );
+            urls.Add(new UrlDescriptor { Url = url, Name = name });
             options.ConfigObject.Urls = urls;
         }
 
@@ -221,6 +221,16 @@ public static void OAuthClientId(this SwaggerUIOptions options, string value)
             options.OAuthConfigObject.ClientId = value;
         }
 
+        /// <summary>
+        /// Default userName
+        /// </summary>
+        /// <param name="options"></param>
+        /// <param name="value"></param>
+        public static void OAuthUsername(this SwaggerUIOptions options, string value)
+        {
+            options.OAuthConfigObject.Username = value;
+        }
+
         /// <summary>
         /// Default clientSecret
         /// </summary>

test/WebSites/OAuth2Integration/Startup.cs

@@ -132,6 +132,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                     c.EnableDeepLinking();
 
                     // Additional OAuth settings (See https://github.com/swagger-api/swagger-ui/blob/v3.10.0/docs/usage/oauth2.md)
+                    c.OAuthUsername("username");
                     c.OAuthClientId("test-id");
                     c.OAuthClientSecret("test-secret");
                     c.OAuthAppName("test-app");