activity pub documented

.rubocop.yml

@@ -8,3 +8,15 @@ Style/StringLiteralsInInterpolation:
 
 Layout/LineLength:
   Max: 190
+
+Metrics/BlockLength:
+  Max: 60
+
+Metrics/ParameterLists:
+  Max: 8
+
+Metrics/MethodLength:
+  Max: 13
+
+Metrics/BlockLength:
+  Max: 80

Gemfile

@@ -9,8 +9,8 @@ gem "pry"
 
 gem "webmock"
 
-gem "sinatra"
 gem "puma"
+gem "sinatra"
 
 gem "rake", "~> 13.0"
 

activitypub.gemspec

@@ -10,10 +10,10 @@ Gem::Specification.new do |spec|
 
   spec.summary       = "A Ruby library for the ActivityPub protocol."
   spec.description   = "A comprehensive library for building and parsing ActivityPub content in Ruby."
-  spec.homepage      = "https://github.com/rauversion/activitypub_ruby"
+  spec.homepage      = "https://github.com/rauversion/activitypub"
   spec.license       = "MIT"
 
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.4")
 
   # spec.metadata["allowed_push_host"] = "TODO: Set to 'http://mygemserver.com'"
 

app.rb

@@ -1,22 +1,24 @@
-require 'sinatra'
+# frozen_string_literal: true
+
+require "sinatra"
 require_relative "lib/activitypub"
 
 # For simplicity, we'll hardcode actor_id and generate a keypair on startup
 actor_id = "https://example.com/actors/1"
 keypair = ActivityPub::Signature.generate_keypair
 outbox = ActivityPub::Outbox.new(actor_id: actor_id, private_key: keypair[:private])
 
-post '/actors/1/outbox' do
+post "/actors/1/outbox" do
   target_inbox_url = params[:inbox_url] # expect the client to provide target inbox URL
   activity_data = params[:activity_data] # and the activity data
 
   response = outbox.send_activity(target_inbox_url, activity_data)
   [response.code.to_i, response.body]
 end
 
-post '/actors/1/inbox' do
+post "/actors/1/inbox" do
   # This is where other actors would send activities to our actor
-  incoming_activity = JSON.parse(params['incoming_activity']) # JSON.parse(request.body.read)
+  incoming_activity = JSON.parse(params["incoming_activity"]) # JSON.parse(request.body.read)
 
   # For demonstration purposes, we'll just print the activity to the console
   puts "Received activity: #{incoming_activity}"
@@ -25,7 +27,7 @@
   [200, "Activity received"]
 end
 
-get '/' do
+get "/" do
   %(
     "ActivityPub Sinatra Example"
     <h2>Send an Activity to Outbox</h2>

lib/activitypub.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
 require "json"
-require 'time'
-require 'base64'
+require "time"
+require "base64"
 require_relative "activitypub/version"
 require_relative "activitypub/activity"
 require_relative "activitypub/object"

lib/activitypub/activity.rb

@@ -1,4 +1,10 @@
+# frozen_string_literal: true
+
 module ActivityPub
+  # The Activity class represents a specific action or event in the ActivityPub protocol.
+  # It encapsulates details of the action being taken and any associated metadata.
+  # This class provides methods for creating, validating, and processing activities
+  # in accordance with the ActivityPub standard.
   class Activity
     # The type of the activity, e.g., 'Create', 'Like', 'Follow', etc.
     attr_accessor :type
@@ -26,7 +32,7 @@ def initialize(type:, actor:, object:, **other_attributes)
     # Convert the activity into a hash representation.
     def to_h
       {
-        '@context': 'https://www.w3.org/ns/activitystreams',
+        '@context': "https://www.w3.org/ns/activitystreams",
         type: @type,
         actor: @actor,
         object: @object
@@ -43,9 +49,9 @@ def to_json(*args)
     # Load an activity from a hash.
     def self.from_h(hash)
       new(
-        type: hash['type'],
-        actor: hash['actor'],
-        object: hash['object']
+        type: hash["type"],
+        actor: hash["actor"],
+        object: hash["object"]
         # Handle any other attributes as needed.
         # ...
       )

lib/activitypub/actor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # The ActivityPub::Actor represents individual and
 # collective entities which perform activities.
 # Commonly used actor types include Person, Organization,
@@ -7,10 +9,15 @@
 # Here's a basic representation for the ActivityPub::Actor:
 
 module ActivityPub
+  # The Actor class represents participants in the ActivityPub network.
+  # An Actor can be an individual user, a group, a service, or any other entity
+  # that performs actions on the network. This class handles details related to
+  # actor identity, public keys, endpoints, and other metadata essential for
+  # secure and accurate communication within the ActivityPub protocol.
   class Actor
     attr_accessor :id, :type, :name, :preferred_username, :inbox, :outbox, :followers, :following
 
-    def initialize(id:, type: 'Person', name:, preferred_username:, inbox:, outbox:, followers: nil, following: nil)
+    def initialize(id:, type: "Person", name:, preferred_username:, inbox:, outbox:, followers: nil, following: nil)
       @id                = id
       @type              = type
       @name              = name
@@ -23,7 +30,7 @@ def initialize(id:, type: 'Person', name:, preferred_username:, inbox:, outbox:,
 
     def to_h
       {
-        '@context': 'https://www.w3.org/ns/activitystreams',
+        '@context': "https://www.w3.org/ns/activitystreams",
         id: @id,
         type: @type,
         name: @name,
@@ -41,14 +48,14 @@ def to_json(*args)
 
     def self.from_h(hash)
       new(
-        id: hash['id'],
-        type: hash['type'] || 'Person',
-        name: hash['name'],
-        preferred_username: hash['preferredUsername'],
-        inbox: hash['inbox'],
-        outbox: hash['outbox'],
-        followers: hash['followers'],
-        following: hash['following']
+        id: hash["id"],
+        type: hash["type"] || "Person",
+        name: hash["name"],
+        preferred_username: hash["preferredUsername"],
+        inbox: hash["inbox"],
+        outbox: hash["outbox"],
+        followers: hash["followers"],
+        following: hash["following"]
       )
     end
   end

lib/activitypub/inbox.rb

@@ -1,7 +1,12 @@
-require 'net/http'
-require 'json'
+# frozen_string_literal: true
+
+require "net/http"
+require "json"
 
 module ActivityPub
+  # The Inbox class manages the reception of activities from other actors.
+  # It is responsible for validating incoming activities, verifying signatures,
+  # and processing or storing them as needed in the context of the ActivityPub protocol.
   class Inbox
     attr_reader :actor_id
 
@@ -17,9 +22,7 @@ def accept_activity(activity_data, headers)
       signature = headers["Signature"]
 
       # Verify the activity's signature
-      unless ActivityPub::Signature.verify?(activity_data, signature, public_key)
-        raise "Invalid signature"
-      end
+      raise "Invalid signature" unless ActivityPub::Signature.verify?(activity_data, signature, public_key)
 
       # Process activity
       process_activity(activity_data)
@@ -35,7 +38,7 @@ def fetch_actor_public_key(actor_id)
 
       # This assumes the public key is stored under a 'publicKey' key in the actor's profile.
       # This structure may vary based on the implementation details of the server hosting the actor's profile.
-      profile['publicKey']['publicKeyPem']
+      profile["publicKey"]["publicKeyPem"]
     end
 
     def process_activity(activity_data)

lib/activitypub/object.rb

@@ -1,8 +1,13 @@
+# frozen_string_literal: true
+
 module ActivityPub
+  # The Object class represents the primary data structure of the ActivityPub protocol.
+  # It provides a foundational element from which specific ActivityPub types (like "Note" or "Event") derive.
+  # This class facilitates the creation, validation, and manipulation of ActivityPub objects.
   class Object
     attr_accessor :id, :type, :published, :updated, :content, :attributed_to
 
-    def initialize(id:, type: 'Object', published: nil, updated: nil, content: nil, attributed_to: nil)
+    def initialize(id:, type: "Object", published: nil, updated: nil, content: nil, attributed_to: nil)
       @id            = id
       @type          = type
       @published     = published || Time.now.utc.iso8601
@@ -13,7 +18,7 @@ def initialize(id:, type: 'Object', published: nil, updated: nil, content: nil,
 
     def to_h
       {
-        '@context': 'https://www.w3.org/ns/activitystreams',
+        '@context': "https://www.w3.org/ns/activitystreams",
         id: @id,
         type: @type,
         published: @published,
@@ -29,22 +34,20 @@ def to_json(*args)
 
     def self.from_h(hash)
       new(
-        id: hash['id'],
-        type: hash['type'] || 'Object',
-        published: hash['published'],
-        updated: hash['updated'],
-        content: hash['content'],
-        attributed_to: hash['attributedTo']
+        id: hash["id"],
+        type: hash["type"] || "Object",
+        published: hash["published"],
+        updated: hash["updated"],
+        content: hash["content"],
+        attributed_to: hash["attributedTo"]
       )
     end
   end
 end
 
-=begin
-  obj = ActivityPub::Object.new(id: 'https://example.com/objects/1', content: 'Hello world!')
-puts obj.to_json
-
-loaded_obj = ActivityPub::Object.from_h(JSON.parse(obj.to_json))
-puts loaded_obj.content # => "Hello world!"
-
-=end
+#   obj = ActivityPub::Object.new(id: 'https://example.com/objects/1', content: 'Hello world!')
+# puts obj.to_json
+#
+# loaded_obj = ActivityPub::Object.from_h(JSON.parse(obj.to_json))
+# puts loaded_obj.content # => "Hello world!"
+#

lib/activitypub/outbox.rb

@@ -1,6 +1,12 @@
-require 'net/http'
+# frozen_string_literal: true
+
+require "net/http"
 
 module ActivityPub
+  # The Outbox class is responsible for sending activities to other actors.
+  # It wraps the process of preparing an activity, signing it, and then delivering it to
+  # the recipient's inbox. This ensures that messages sent via ActivityPub are
+  # authenticated and securely delivered.
   class Outbox
     attr_reader :actor_id, :private_key
 
@@ -28,7 +34,7 @@ def send_activity(target_inbox_url, activity_data)
     def post_activity(inbox_url, activity_data, signature)
       uri = URI(inbox_url)
       http = Net::HTTP.new(uri.host, uri.port)
-      request = Net::HTTP::Post.new(uri.path, { 'Content-Type' => 'application/ld+json', 'Signature' => signature })
+      request = Net::HTTP::Post.new(uri.path, { "Content-Type" => "application/ld+json", "Signature" => signature })
       request.body = activity_data
       http.request(request)
     end

lib/activitypub/signature.rb

@@ -1,11 +1,16 @@
-require 'openssl'
+# frozen_string_literal: true
+
+require "openssl"
 
 # Digital signatures are essential in federated networks
 # like ActivityPub to ensure data integrity and authenticity.
 # A commonly used algorithm for generating these signatures
 # in the ActivityPub community is the RSA-SHA256 algorithm.
 
 module ActivityPub
+  # This class handles the generation and verification of ActivityPub signatures.
+  # It ensures that outgoing messages are authenticated and incoming messages
+  # are verified against a known public key.
   class Signature
     # Generates a new RSA private and public key pair
     def self.generate_keypair
@@ -17,7 +22,7 @@ def self.generate_keypair
     def self.sign(data, private_key_pem)
       private_key = OpenSSL::PKey::RSA.new(private_key_pem)
       signature = private_key.sign(OpenSSL::Digest::SHA256.new, data)
-      Base64.encode64(signature).gsub("\n", '')
+      Base64.encode64(signature).gsub("\n", "")
     end
 
     # Verifies the signature with the provided public key

spec/activity_spec.rb

@@ -1,36 +1,38 @@
+# frozen_string_literal: true
+
 RSpec.describe ActivityPub::Activity do
-  describe '#initialize' do
-    subject { described_class.new(type: 'Like', actor: 'https://example.com/users/alice', object: 'https://example.com/posts/1') }
+  describe "#initialize" do
+    subject { described_class.new(type: "Like", actor: "https://example.com/users/alice", object: "https://example.com/posts/1") }
 
-    it 'initializes with given attributes' do
-      expect(subject.type).to eq('Like')
-      expect(subject.actor).to eq('https://example.com/users/alice')
-      expect(subject.object).to eq('https://example.com/posts/1')
+    it "initializes with given attributes" do
+      expect(subject.type).to eq("Like")
+      expect(subject.actor).to eq("https://example.com/users/alice")
+      expect(subject.object).to eq("https://example.com/posts/1")
     end
   end
 
-  describe '#to_json' do
-    subject { described_class.new(type: 'Like', actor: 'https://example.com/users/alice', object: 'https://example.com/posts/1') }
+  describe "#to_json" do
+    subject { described_class.new(type: "Like", actor: "https://example.com/users/alice", object: "https://example.com/posts/1") }
 
-    it 'converts the activity to a JSON representation' do
+    it "converts the activity to a JSON representation" do
       json_output = subject.to_json
       parsed_output = JSON.parse(json_output)
 
-      expect(parsed_output['type']).to eq('Like')
-      expect(parsed_output['actor']).to eq('https://example.com/users/alice')
-      expect(parsed_output['object']).to eq('https://example.com/posts/1')
+      expect(parsed_output["type"]).to eq("Like")
+      expect(parsed_output["actor"]).to eq("https://example.com/users/alice")
+      expect(parsed_output["object"]).to eq("https://example.com/posts/1")
     end
   end
 
-  describe '.from_h' do
-    let(:activity_hash) { { 'type' => 'Like', 'actor' => 'https://example.com/users/alice', 'object' => 'https://example.com/posts/1' } }
+  describe ".from_h" do
+    let(:activity_hash) { { "type" => "Like", "actor" => "https://example.com/users/alice", "object" => "https://example.com/posts/1" } }
 
-    it 'loads an activity from a hash' do
+    it "loads an activity from a hash" do
       activity = described_class.from_h(activity_hash)
 
-      expect(activity.type).to eq('Like')
-      expect(activity.actor).to eq('https://example.com/users/alice')
-      expect(activity.object).to eq('https://example.com/posts/1')
+      expect(activity.type).to eq("Like")
+      expect(activity.actor).to eq("https://example.com/users/alice")
+      expect(activity.object).to eq("https://example.com/posts/1")
     end
   end
 end