Allow enabling/disabling capabilities.

See mastodon/fediverse_auxiliary_service_provider_specifications#48
for context.

Author: oneiros

fasp_base/Gemfile.lock

@@ -90,8 +90,8 @@ GEM
     benchmark (0.4.0)
     bigdecimal (3.1.9)
     builder (3.3.0)
-    concurrent-ruby (1.3.4)
-    connection_pool (2.4.1)
+    concurrent-ruby (1.3.5)
+    connection_pool (2.5.0)
     crack (1.0.0)
       bigdecimal
       rexml
@@ -101,29 +101,30 @@ GEM
       irb (~> 1.10)
       reline (>= 0.3.8)
     drb (2.2.1)
-    erubi (1.13.0)
+    erubi (1.13.1)
     globalid (1.2.1)
       activesupport (>= 6.1)
     hashdiff (1.1.2)
     http-2 (1.0.2)
     httpx (1.4.0)
       http-2 (>= 1.0.0)
-    i18n (1.14.6)
+    i18n (1.14.7)
       concurrent-ruby (~> 1.0)
     io-console (0.8.0)
-    irb (1.14.3)
+    irb (1.15.1)
+      pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
-    json (2.9.1)
-    language_server-protocol (3.17.0.3)
+    json (2.10.1)
+    language_server-protocol (3.17.0.4)
     linzer (0.6.2)
       openssl (~> 3.0, >= 3.0.0)
       rack (>= 2.2, < 4.0)
       starry (~> 0.2)
       stringio (~> 3.1, >= 3.1.2)
       uri (~> 1.0, >= 1.0.2)
-    logger (1.6.4)
-    loofah (2.23.1)
+    logger (1.6.5)
+    loofah (2.24.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
     mail (2.8.1)
@@ -133,50 +134,62 @@ GEM
       net-smtp
     marcel (1.0.4)
     mini_mime (1.1.5)
+    mini_portile2 (2.8.8)
     minitest (5.25.4)
-    net-imap (0.5.2)
+    net-imap (0.5.6)
       date
       net-protocol
     net-pop (0.1.2)
       net-protocol
     net-protocol (0.2.2)
       timeout
-    net-smtp (0.5.0)
+    net-smtp (0.5.1)
       net-protocol
     nio4r (2.7.4)
-    nokogiri (1.17.2-aarch64-linux)
+    nokogiri (1.18.2)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    nokogiri (1.17.2-arm-linux)
+    nokogiri (1.18.2-aarch64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.17.2-arm64-darwin)
+    nokogiri (1.18.2-aarch64-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.17.2-x86-linux)
+    nokogiri (1.18.2-arm-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.17.2-x86_64-darwin)
+    nokogiri (1.18.2-arm-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.17.2-x86_64-linux)
+    nokogiri (1.18.2-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.18.2-x86_64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.18.2-x86_64-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.18.2-x86_64-linux-musl)
       racc (~> 1.4)
     openssl (3.3.0)
     parallel (1.26.3)
-    parser (3.3.6.0)
+    parser (3.3.7.1)
       ast (~> 2.4.1)
       racc
+    pp (0.6.2)
+      prettyprint
+    prettyprint (0.2.0)
     propshaft (1.1.0)
       actionpack (>= 7.0.0)
       activesupport (>= 7.0.0)
       rack
       railties (>= 7.0.0)
-    psych (5.2.2)
+    psych (5.2.3)
       date
       stringio
     public_suffix (6.0.1)
     puma (6.6.0)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (3.1.8)
-    rack-session (2.0.0)
+    rack (3.1.10)
+    rack-session (2.1.0)
+      base64 (>= 0.1.0)
       rack (>= 3.0.0)
-    rack-test (2.1.0)
+    rack-test (2.2.0)
       rack (>= 1.3)
     rackup (2.2.1)
       rack (>= 3)
@@ -211,31 +224,31 @@ GEM
       zeitwerk (~> 2.6)
     rainbow (3.1.1)
     rake (13.2.1)
-    rdoc (6.10.0)
+    rdoc (6.12.0)
       psych (>= 4.0.0)
-    regexp_parser (2.9.3)
+    regexp_parser (2.10.0)
     reline (0.6.0)
       io-console (~> 0.5)
     rexml (3.4.0)
-    rubocop (1.69.2)
+    rubocop (1.71.2)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 2.9.3, < 3.0)
-      rubocop-ast (>= 1.36.2, < 2.0)
+      rubocop-ast (>= 1.38.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 4.0)
-    rubocop-ast (1.37.0)
+    rubocop-ast (1.38.0)
       parser (>= 3.3.1.0)
     rubocop-minitest (0.36.0)
       rubocop (>= 1.61, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-performance (1.23.0)
+    rubocop-performance (1.23.1)
       rubocop (>= 1.48.1, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-rails (2.27.0)
+    rubocop-rails (2.29.1)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.52.0, < 2.0)
@@ -264,7 +277,7 @@ GEM
     timeout (0.4.3)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (3.1.2)
+    unicode-display_width (3.1.4)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
     uri (1.0.2)
@@ -273,7 +286,8 @@ GEM
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    websocket-driver (0.7.6)
+    websocket-driver (0.7.7)
+      base64
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
     zeitwerk (2.7.1)

fasp_base/app/controllers/fasp_base/fasp/activations_controller.rb

@@ -0,0 +1,25 @@
+module FaspBase
+  class Fasp::ActivationsController < ApplicationController
+    include ApiAuthentication
+
+    def create
+      current_server.enable_capability!(params[:capability_id], version: params[:version])
+
+      respond_to do |format|
+        format.json { head :no_content }
+      end
+    rescue ArgumentError
+      respond_to do |format|
+        format.json { head :not_found }
+      end
+    end
+
+    def destroy
+      current_server.disable_capability!(params[:capability_id], version: params[:version])
+
+      respond_to do |format|
+        format.json { head :no_content }
+      end
+    end
+  end
+end

fasp_base/app/models/fasp_base/server.rb

@@ -30,6 +30,25 @@ def url(path)
       "#{base}#{path}"
     end
 
+    def capability_enabled?(capability, version:)
+      enabled_capabilities && enabled_capabilities.include?({ "id" => capability, "version" => version })
+    end
+
+    def enable_capability!(capability, version:)
+      raise ArgumentError, "unsupported capability" unless FaspBase.supports?(capability, version:)
+      self.enabled_capabilities ||= []
+      enabled_capabilities << { "id" => capability, "version" => version.to_i }
+      enabled_capabilities.uniq!
+      save!
+    end
+
+    def disable_capability!(capability, version:)
+      return if enabled_capabilities.blank?
+
+      enabled_capabilities.delete({ "id" => capability, "version" => version.to_i })
+      save!
+    end
+
     private
 
     def create_keypair

fasp_base/config/routes.rb

@@ -1,5 +1,8 @@
 FaspBase::Engine.routes.draw do
   namespace :fasp do
+    resources :capabilities, only: [] do
+      resource :activation, path: "/:version/activation", only: [ :create, :destroy ]
+    end
     resource :provider_info, only: :show
   end
 

fasp_base/db/migrate/20250212113456_add_enabled_capabilities_to_fasp_base_servers.rb

@@ -0,0 +1,5 @@
+class AddEnabledCapabilitiesToFaspBaseServers < ActiveRecord::Migration[8.0]
+  def change
+    add_column :fasp_base_servers, :enabled_capabilities, :json
+  end
+end

fasp_base/lib/fasp_base.rb

@@ -18,4 +18,10 @@ def self.base_url
     protocol = Rails.env.production? ? "https" : "http"
     "#{protocol}://#{domain}/fasp"
   end
+
+  def self.supports?(capability, version:)
+    capabilities.any? do |supported_capability|
+      supported_capability[:id] == capability && supported_capability[:version].start_with?(version.to_s)
+    end
+  end
 end

fasp_base/lib/generators/fasp_base/install/templates/initializers/fasp_base.rb

@@ -6,7 +6,7 @@
   f.domain = ENV["DOMAIN"] || ActionController::Base.default_url_options[:host] || "localhost:3000"
 
   # Add supported capabilities here:
-  f.capabilities = [ ]
+  f.capabilities = []
 
   # Additional metadata
   # f.privacy_policy_url = ENV["PRIVACY_POLICY_URL"]

fasp_base/test/dummy/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2024_11_18_142403) do
+ActiveRecord::Schema[8.0].define(version: 2025_02_12_113456) do
   create_table "fasp_base_servers", force: :cascade do |t|
     t.string "base_url", null: false
     t.integer "user_id", null: false
@@ -20,6 +20,7 @@
     t.string "fasp_remote_id"
     t.string "public_key_pem"
     t.string "registration_completion_uri"
+    t.json "enabled_capabilities"
     t.index [ "base_url" ], name: "index_fasp_base_servers_on_base_url", unique: true
     t.index [ "user_id" ], name: "index_fasp_base_servers_on_user_id"
   end

fasp_base/test/integration/activation_test.rb

@@ -0,0 +1,36 @@
+require "test_helper"
+
+class ActivationTest < ActionDispatch::IntegrationTest
+  include FaspBase::IntegrationTestHelper
+
+  setup do
+    @server = fasp_base_servers(:mastodon_server)
+    FaspBase.capabilities = [
+      { id: "test", version: "5.4" }
+    ]
+  end
+
+  teardown do
+    FaspBase.capabilities = []
+  end
+
+  test "POST /fasp/capabilities/:name/:version/activation enables capability" do
+    post fasp_base.fasp_capability_activation_path("test", version: "5"),
+      as: :json,
+      headers: request_authentication_headers(@server, :post, fasp_base.fasp_capability_activation_url("test", version: "5"), "")
+
+    assert_response :no_content
+    assert @server.reload.capability_enabled?("test", version: 5)
+  end
+
+  test "DELETE /fasp/capabilities/:name/:version/activation disables capability" do
+    @server.enable_capability!("test", version: 5)
+
+    delete fasp_base.fasp_capability_activation_path("test", version: "5"),
+      as: :json,
+      headers: request_authentication_headers(@server, :delete, fasp_base.fasp_capability_activation_url("test", version: "5"), "")
+
+    assert_response :no_content
+    assert_not @server.reload.capability_enabled?("test", version: 5)
+  end
+end

fasp_base/test/models/fasp_base/server_test.rb

@@ -2,8 +2,36 @@
 
 module FaspBase
   class ServerTest < ActiveSupport::TestCase
-    # test "the truth" do
-    #   assert true
-    # end
+    setup do
+      @server = fasp_base_servers(:mastodon_server)
+      FaspBase.capabilities = [
+        { id: "test", version: "2.1" }
+      ]
+    end
+
+    teardown do
+      FaspBase.capabilities = []
+    end
+
+    test "#enable_capability! enables a capability" do
+      assert_not @server.capability_enabled?("test", version: 2)
+      @server.enable_capability!("test", version: 2)
+
+      assert @server.capability_enabled?("test", version: 2)
+    end
+
+    test "#enable_capability! raises if a capability is unknown/unsupported" do
+      assert_raises ArgumentError do
+        @server.enable_capability!("unknown", version: 4)
+      end
+    end
+
+    test "#disable_capability! disables a capability that was previously enabled" do
+      @server.enable_capability!("test", version: 2)
+      assert @server.capability_enabled?("test", version: 2)
+      @server.disable_capability!("test", version: 2)
+
+      assert_not @server.capability_enabled?("test", version: "2")
+    end
   end
 end