Add Patreon to the list of supported providers

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.Userinfo.cs

@@ -202,7 +202,8 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                 response.Content.Headers.ContentType = context.Registration.ProviderName switch
                 {
                     Providers.Mixcloud or // Mixcloud returns JSON-formatted contents declared as "text/javascript".
-                    Providers.Vimeo // Vimeo returns JSON-formatted contents declared as "application/vnd.vimeo.user+json".
+                    Providers.Patreon  or // Patreon returns JSON-formatted contents declared as "application/vnd.api+json".
+                    Providers.Vimeo       // Vimeo returns JSON-formatted contents declared as "application/vnd.vimeo.user+json".
                         => new MediaTypeHeaderValue(MediaTypes.Json)
                         {
                             CharSet = Charsets.Utf8
@@ -253,6 +254,11 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                         is { ValueKind: JsonValueKind.Object } element ?
                         new(element) : throw new InvalidOperationException(SR.FormatID0334("user")),
 
+                    // Patreon returns a nested "attributes" object that is itself nested in a "data" node.
+                    Providers.Patreon => (JsonElement) context.Response["data"]?["attributes"]
+                        is { ValueKind: JsonValueKind.Object } element ?
+                        new(element) : throw new InvalidOperationException(SR.FormatID0334("attributes")),
+
                     // StackExchange returns an "items" array containing a single element.
                     Providers.StackExchange => (JsonElement) context.Response["items"]
                         is { ValueKind: JsonValueKind.Array } element && element.GetArrayLength() is 1 ?

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.cs

@@ -393,6 +393,16 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                 context.UserinfoRequest["projection"] = string.Concat("(", string.Join(",", options.Fields), ")");
             }
 
+            // Patreon limits the number of fields returned by the userinfo endpoint
+            // but allows returning additional information using special parameters that
+            // determine what fields will be returned as part of the userinfo response.
+            else if (context.Registration.ProviderName is Providers.Patreon)
+            {
+                var options = context.Registration.GetPatreonOptions();
+
+                context.UserinfoRequest["fields[user]"] = string.Join(",", options.UserFields);
+            }
+
             // StackOverflow requires sending an application key and a site parameter
             // containing the name of the site from which the user profile is retrieved.
             else if (context.Registration.ProviderName is Providers.StackExchange)

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationProviders.xml

@@ -368,6 +368,40 @@
     </Environment>
   </Provider>
 
+  <!--
+                                        ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
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+  -->
+
+  <Provider Name="Patreon" Documentation="https://docs.patreon.com/#oauth">
+    <Environment Issuer="https://www.patreon.com/">
+      <Configuration AuthorizationEndpoint="https://www.patreon.com/oauth2/authorize"
+                     TokenEndpoint="https://www.patreon.com/api/oauth2/token"
+                     UserinfoEndpoint="https://www.patreon.com/api/oauth2/v2/identity">
+        <GrantType Value="authorization_code" />
+        <GrantType Value="refresh_token" />
+      </Configuration>
+    </Environment>
+
+    <Setting PropertyName="UserFields" ParameterName="fields" Collection="true" Type="String"
+             Description="The list of user fields to expand from the userinfo endpoint (by default, all known fields are requested)">
+      <Item Value="about"              Default="true" Required="false" />
+      <Item Value="created"            Default="true" Required="false" />
+      <Item Value="email"              Default="true" Required="false" />
+      <Item Value="first_name"         Default="true" Required="false" />
+      <Item Value="full_name"          Default="true" Required="false" />
+      <Item Value="image_url"          Default="true" Required="false" />
+      <Item Value="last_name"          Default="true" Required="false" />
+      <Item Value="social_connections" Default="true" Required="false" />
+      <Item Value="thumb_url"          Default="true" Required="false" />
+      <Item Value="url"                Default="true" Required="false" />
+      <Item Value="vanity"             Default="true" Required="false" />
+    </Setting>
+  </Provider>
+
   <!--
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