Add offline_access scope

app/lib/scope_transformer.rb

@@ -14,6 +14,8 @@ class ScopeTransformer < Parslet::Transform
 
       # # override for profile scope which is read only
       @access = %w(read) if @term == 'profile'
+      # Override offline_access since it doesn't imply read or write access:
+      @access = %w(offline) if @term == 'offline_access'
     end
 
     def key

config/initializers/doorkeeper.rb

@@ -35,10 +35,10 @@ Doorkeeper.configure do
   # context.client for client (Doorkeeper::Application)
   # context.scopes for scopes
   custom_access_token_expires_in do |context|
-    # If the client is confidential (all clients pre 4.3), then we don't want to
-    # expire access tokens. Applications created by users are also considered
-    # confidential.
-    if context.client.confidential?
+    # If the client is confidential (all clients pre 4.3) and it hasn't
+    # requested offline_access, then we don't want to expire access tokens.
+    # Applications created by users are also considered confidential.
+    if context.client.confidential? && !context.scopes.exists?('offline_access')
       nil
     else
       15.minutes.to_i
@@ -80,6 +80,7 @@ Doorkeeper.configure do
   # https://github.com/doorkeeper-gem/doorkeeper/wiki/Using-Scopes
   default_scopes  :read
   optional_scopes :profile,
+                  :offline_access,
                   :write,
                   :'write:accounts',
                   :'write:blocks',

config/locales/doorkeeper.en.yml

@@ -89,6 +89,7 @@ en:
         invalid_request:
           missing_param: 'Missing required parameter: %{value}.'
           request_not_authorized: Request need to be authorized. Required parameter for authorizing request is missing or invalid.
+          offline_access_only: The offline_access scope can only be used with other scopes.
           unknown: The request is missing a required parameter, includes an unsupported parameter value, or is otherwise malformed.
         invalid_resource_owner: The provided resource owner credentials are not valid, or resource owner cannot be found
         invalid_scope: The requested scope is invalid, unknown, or malformed.
@@ -118,6 +119,7 @@ en:
         read: Read-only access
         read/write: Read and write access
         write: Write-only access
+        offline: Access for an extended period of time
       title:
         accounts: Accounts
         admin/accounts: Administration of accounts
@@ -138,6 +140,7 @@ en:
         notifications: Notifications
         profile: Your Mastodon profile
         push: Push notifications
+        offline_access: Offline access
         reports: Reports
         search: Search
         statuses: Posts

spec/lib/scope_transformer_spec.rb

@@ -23,6 +23,12 @@ RSpec.describe ScopeTransformer do
       it_behaves_like 'a scope', nil, 'profile', 'read'
     end
 
+    context 'with scope "offline_access"' do
+      let(:input) { 'offline_access' }
+
+      it_behaves_like 'a scope', nil, 'offline_access', 'offline'
+    end
+
     context 'with scope "read"' do
       let(:input) { 'read' }