gonna keep on keeping on till the build works

- Added a metadata field (forDomain:) to the Fastmail Forwarder API
  request that's set to the domain name of the item being added to the
  vault, or to "" if the username generator is being used in standalone
  mode. This allows the user's Fastmail account to display the domain
  name for the username that was generated.

global.json

@@ -0,0 +1,7 @@
+{
+  "sdk": {
+    "version": "7.0.400",
+    "rollForward": "latestPatch",
+    "allowPrerelease": false
+  }
+}

src/Core/Models/Domain/UsernameGenerationOptions.cs

@@ -46,7 +46,11 @@ namespace Bit.Core.Models.Domain
                 case ForwardedEmailServiceType.DuckDuckGo:
                     return new ForwarderOptions { ApiKey = DuckDuckGoApiKey };
                 case ForwardedEmailServiceType.Fastmail:
-                    return new ForwarderOptions { ApiKey = FastMailApiKey };
+                    return new FastmailForwarderOptions
+                    {
+                        ApiKey = FastMailApiKey,
+                        Website = EmailWebsite
+                    };
                 case ForwardedEmailServiceType.FirefoxRelay:
                     return new ForwarderOptions { ApiKey = FirefoxRelayApiAccessToken };
                 case ForwardedEmailServiceType.SimpleLogin:

src/Core/Services/EmailForwarders/FastmailForwarder.cs

@@ -9,16 +9,21 @@ using Newtonsoft.Json.Linq;
 
 namespace Bit.Core.Services.EmailForwarders
 {
-    public class FastmailForwarder : BaseForwarder<ForwarderOptions>
+    public class FastmailForwarderOptions : ForwarderOptions
+    {
+        public string Website { get; set; }
+    }
+
+    public class FastmailForwarder : BaseForwarder<FastmailForwarderOptions>
     {
         protected override string RequestUri => "https://api.fastmail.com/jmap/api/";
 
-        protected override void ConfigureHeaders(HttpRequestHeaders headers, ForwarderOptions options)
+        protected override void ConfigureHeaders(HttpRequestHeaders headers, FastmailForwarderOptions options)
         {
             headers.Add("Authorization", $"Bearer {options.ApiKey}");
         }
 
-        protected override async Task<HttpContent> GetContentAsync(IApiService apiService, ForwarderOptions options)
+        protected override async Task<HttpContent> GetContentAsync(IApiService apiService, FastmailForwarderOptions options)
         {
             string accountId = null;
             try
@@ -55,7 +60,8 @@ namespace Bit.Core.Services.EmailForwarders
                                         ["state"] = "enabled",
                                         ["description"] = "",
                                         ["url"] = "",
-                                        ["emailPrefix"] = ""
+                                        ["emailPrefix"] = "",
+                                        ["forDomain"] = options.Website ?? ""
                                     }
                                 }
                             },

src/Core/Services/UsernameGenerationService.cs

@@ -148,6 +148,13 @@ namespace Bit.Core.Services
                                     .GenerateAsync(_apiService, forwardedEmailOptions);
             }
 
+            if (options.ServiceType == ForwardedEmailServiceType.Fastmail)
+            {
+                var fastmailEmailOptions = (FastmailForwarderOptions)options.GetForwarderOptions();
+                return await new FastmailForwarder()
+                                    .GenerateAsync(_apiService, fastmailEmailOptions);
+            }
+
             BaseForwarder<ForwarderOptions> simpleForwarder = null;
 
             switch (options.ServiceType)
@@ -161,9 +168,6 @@ namespace Bit.Core.Services
                 case ForwardedEmailServiceType.DuckDuckGo:
                     simpleForwarder = new DuckDuckGoForwarder();
                     break;
-                case ForwardedEmailServiceType.Fastmail:
-                    simpleForwarder = new FastmailForwarder();
-                    break;
                 default:
                     _logger.Value.Error($"Error UsernameGenerationService: ForwardedEmailServiceType {options.ServiceType} not implemented.");
                     return Constants.DefaultUsernameGenerated;