[Spike] Automatically handle and enforce BlockKit limits

lib/slack/block_kit.rb

@@ -10,6 +10,17 @@ module Layout; end
 
     module_function
 
+    def configuration
+      @configuration ||= Configuration.new
+
+      yield(@configuration) if block_given?
+
+      @configuration
+    end
+    class << self
+      alias config configuration
+    end
+
     def blocks
       blocks = Blocks.new
 

lib/slack/block_kit/configuration.rb

@@ -0,0 +1,15 @@
+module Slack
+  module BlockKit
+    class Configuration
+      attr_accessor :autofix_invalid_blocks
+
+      def initialize
+        @autofix_invalid_blocks = false
+      end
+
+      def autofix_invalid_blocks?
+        !!@autofix_invalid_blocks
+      end
+    end
+  end
+end

lib/slack/block_kit/layout/actions.rb

@@ -7,6 +7,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#actions
       class Actions
+        prepend Limiters::BlockId
         TYPE = 'actions'
 
         attr_accessor :elements

lib/slack/block_kit/layout/context.rb

@@ -7,6 +7,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#context
       class Context
+        prepend Limiters::BlockId
         TYPE = 'context'
 
         attr_accessor :elements

lib/slack/block_kit/layout/divider.rb

@@ -8,6 +8,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#divider
       class Divider
+        prepend Limiters::BlockId
         TYPE = 'divider'
 
         def initialize(block_id: nil)

lib/slack/block_kit/layout/header.rb

@@ -9,6 +9,7 @@ module Layout
       #
       # https://api.slack.com/reference/block-kit/blocks#header
       class Header
+        prepend Limiters::BlockId
         TYPE = 'header'
 
         def initialize(text:, block_id: nil, emoji: nil)

lib/slack/block_kit/layout/image.rb

@@ -7,6 +7,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#context
       class Image
+        prepend Limiters::BlockId
         TYPE = 'image'
 
         def initialize(url:, alt_text:, title: nil, block_id: nil, emoji: nil)

lib/slack/block_kit/layout/input.rb

@@ -9,6 +9,7 @@ module Layout
       #
       # https://api.slack.com/reference/block-kit/blocks#input
       class Input # rubocop:disable Metrics/ClassLength
+        prepend Limiters::BlockId
         TYPE = 'input'
 
         attr_accessor :label, :element, :block_id, :hint, :optional, :emoji

lib/slack/block_kit/layout/rich_text.rb

@@ -11,6 +11,7 @@ module Layout
       #
       # https://api.slack.com/reference/block-kit/blocks#rich_text
       class RichText
+        prepend Limiters::BlockId
         TYPE = 'rich_text'
 
         attr_accessor :elements

lib/slack/block_kit/layout/section.rb

@@ -9,6 +9,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#section
       class Section
+        prepend Limiters::BlockId
         include Section::MultiSelectElements
         TYPE = 'section'
 

lib/slack/block_kit/layout/video.rb

@@ -9,6 +9,7 @@ module Layout
       #
       # https://api.slack.com/reference/messaging/blocks#context
       class Video
+        prepend Limiters::BlockId
         TYPE = 'video'
 
         def initialize(alt_text:, thumbnail_url:, video_url:, title:, description:, **optional_args)

lib/slack/block_kit/limiters/block_id.rb

@@ -0,0 +1,19 @@
+module Slack
+  module BlockKit
+    module Limiters
+      module BlockId
+        BLOCK_ID_LIMIT = 255
+
+        def as_json
+          json = super
+
+          if Slack::BlockKit.config.autofix_invalid_blocks? && json[:block_id]
+            json[:block_id] = Utils.truncate(json[:block_id].to_s, length: BLOCK_ID_LIMIT, omission: "")
+          end
+
+          json
+        end
+      end
+    end
+  end
+end

lib/slack/block_kit/utils.rb

@@ -0,0 +1,23 @@
+module Slack
+  module BlockKit
+    module Utils
+      # Truncate a string to a certain length, adding an optional omission
+      # string if the string is truncated. This is generally used to ensure
+      # that certain block limits do not exceed their maximum length when
+      # autofixing is enabled.
+      #
+      # See: https://api.rubyonrails.org/classes/String.html#method-i-truncate
+      def self.truncate(text, length:, omission: "...", separator: nil)
+        return text.dup unless text.length > length
+
+        omission ||= ""
+        length_with_room_for_omission = length - omission.length
+
+        stop = text.rindex(separator, length_with_room_for_omission) if separator
+        stop ||= length_with_room_for_omission
+
+        "#{text[0, stop]}#{omission}"
+      end
+    end
+  end
+end

spec/lib/slack/block_kit/layout/actions_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Actions do
   subject(:actions_json) { instance.as_json }
@@ -20,6 +21,8 @@
     expect(actions_json).to eq(expected_json)
   end
 
+  it_behaves_like 'a block that handles block_id length limits'
+
   describe '#button' do
     let(:expected_element_json) do
       {

spec/lib/slack/block_kit/layout/context_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Context do
   subject(:context_json) { instance.as_json }
@@ -19,6 +20,8 @@
     expect(context_json).to eq(expected_json)
   end
 
+  it_behaves_like 'a block that handles block_id length limits'
+
   describe '#image' do
     let(:expected_json) do
       {

spec/lib/slack/block_kit/layout/divider_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
+
+RSpec.describe Slack::BlockKit::Layout::Divider do
+  let(:instance) { described_class.new(**params) }
+
+  it_behaves_like 'a block that handles block_id length limits'
+
+  describe '#as_json' do
+    subject { instance.as_json }
+
+    let(:params) { {} }
+    let(:expected_json) { { type: 'divider' } }
+
+    it { is_expected.to eq expected_json }
+
+    context 'with block_id' do
+      let(:params) { { block_id: '1123' } }
+      let(:expected_json) do
+        {
+          type: 'divider',
+          block_id: '1123'
+        }
+      end
+
+      it { is_expected.to eq expected_json }
+    end
+  end
+end

spec/lib/slack/block_kit/layout/header_spec.rb

@@ -1,10 +1,13 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Header do
   let(:instance) { described_class.new(**params) }
 
+  it_behaves_like 'a block that handles block_id length limits', text: '__TEXT__'
+
   describe '#as_json' do
     subject { instance.as_json }
 

spec/lib/slack/block_kit/layout/image_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
+
+RSpec.describe Slack::BlockKit::Layout::Image do
+  let(:instance) { described_class.new(**params) }
+
+  it_behaves_like 'a block that handles block_id length limits', url: '__URL__', alt_text: '__ALT_TEXT__'
+
+  describe '#as_json' do
+    subject { instance.as_json }
+
+    let(:params) do
+      {
+        url: '__URL__',
+        alt_text: '__ALT_TEXT__'
+      }
+    end
+    let(:expected_json) do
+      {
+        type: 'image',
+        image_url: '__URL__',
+        alt_text: '__ALT_TEXT__'
+      }
+    end
+
+    it { is_expected.to eq expected_json }
+
+    context 'with all arguments' do
+      let(:params) do
+        {
+          url: '__URL__',
+          alt_text: '__ALT_TEXT__',
+          block_id: '1123',
+          title: 'This is a title',
+        }
+      end
+      let(:expected_json) do
+        {
+          type: 'image',
+          image_url: '__URL__',
+          alt_text: '__ALT_TEXT__',
+          block_id: '1123',
+          title: {
+            type: 'plain_text',
+            text: 'This is a title'
+          }
+        }
+      end
+
+      it { is_expected.to eq expected_json }
+    end
+  end
+end

spec/lib/slack/block_kit/layout/input_spec.rb

@@ -1,10 +1,13 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Input do
   subject(:input_json) { instance.as_json }
 
+  it_behaves_like 'a block that handles block_id length limits', label: 'Name', element: Slack::BlockKit::Element::PlainTextInput.new(action_id: '__ACTION_ID__')
+
   let(:instance) { described_class.new(**params) }
   let(:optional) { false }
   let(:hint) { 'Your Name' }

spec/lib/slack/block_kit/layout/rich_text_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::RichText do
   subject(:rich_text_json) { instance.as_json }
@@ -19,6 +20,8 @@
     expect(rich_text_json).to eq(expected_json)
   end
 
+  it_behaves_like 'a block that handles block_id length limits'
+
   describe '#rich_text_section' do
     let(:expected_json) do
       {

spec/lib/slack/block_kit/layout/section_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Section do
   subject(:section_json) { instance.as_json }
@@ -26,6 +27,8 @@
     expect(section_json).to eq(expected_json)
   end
 
+  it_behaves_like 'a block that handles block_id length limits'
+
   describe '#mrkdwn' do
     let(:expected_json) do
       {

spec/lib/slack/block_kit/layout/video_spec.rb

@@ -1,8 +1,11 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require_relative '../limiters/block_id_helpers'
 
 RSpec.describe Slack::BlockKit::Layout::Video do
+  it_behaves_like 'a block that handles block_id length limits', alt_text: 'test', thumbnail_url: 'test', video_url: 'test', title: 'test', description: 'test'
+
   describe '.as_json' do
     subject(:video_json) { instance.as_json }
 

spec/lib/slack/block_kit/limiters/block_id_helpers.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.shared_examples_for 'a block that handles block_id length limits' do |**params|
+  let(:block) { described_class.new(block_id: block_id, **params) }
+  let(:block_id) { 'a' * (Slack::BlockKit::Limiters::BlockId::BLOCK_ID_LIMIT + 1) }
+
+  subject(:json) { block.as_json }
+
+  context 'when autofix is disabled' do
+    it 'does not truncate the block_id when converting to JSON' do
+      expect(json[:block_id]).to eq(block_id)
+    end
+  end
+
+  context 'when autofix is enabled' do
+    let(:block) { described_class.new(block_id: block_id, **params) }
+
+    around do |example|
+      Slack::BlockKit.configuration.autofix_invalid_blocks = true
+      example.run
+      Slack::BlockKit.configuration.autofix_invalid_blocks = false
+    end
+
+    it 'truncates the block_id when converting to JSON' do
+      expect(json[:block_id]).to eq('a' * Slack::BlockKit::Limiters::BlockId::BLOCK_ID_LIMIT)
+    end
+
+    context 'when the block_id is already within the limit' do
+      let(:block_id) { 'a' * (Slack::BlockKit::Limiters::BlockId::BLOCK_ID_LIMIT - 1) }
+
+      it 'does not truncate the block_id' do
+        expect(json[:block_id]).to eq(block_id)
+      end
+    end
+
+    context 'when no block_id is provided' do
+      let(:block) { described_class.new(**params) }
+      let(:block_id) { nil }
+
+      it 'does not include block_id in the JSON' do
+        expect(json).not_to have_key(:block_id)
+      end
+    end
+  end
+end