feat: queue GitHub comment bounty intents

app/models/github/bounty_intent.rb

@@ -0,0 +1,57 @@
+require 'bigdecimal'
+
+class Github::BountyIntent
+  AMOUNT_PATTERN = /(?:^|\s)(?:\$\+|\+\$|\$)\s*(\d+(?:\.\d{1,2})?)(?=\s|$|[[:punct:]])/
+
+  attr_reader :amount
+
+  def initialize(amount)
+    @amount = BigDecimal(amount.to_s)
+  end
+
+  def self.extract(text)
+    text.to_s.scan(AMOUNT_PATTERN).flatten.map do |amount|
+      new(amount)
+    end.select(&:valid?)
+  end
+
+  def self.queue_from_comment(comment_data, issue:, actor:)
+    intents = extract(comment_data.try(:[], 'body'))
+    return [] if intents.empty? || issue.blank? || actor.try(:person).blank?
+
+    intents.map { |intent| intent.queue_for(actor.person, issue) }.compact
+  end
+
+  def valid?
+    amount > 0
+  end
+
+  def to_cart_item(issue)
+    {
+      item_type: 'Bounty',
+      amount: amount.to_s('F'),
+      currency: 'USD',
+      issue_id: issue.id,
+      tweet: false
+    }
+  end
+
+  def queue_for(person, issue)
+    cart = person.shopping_cart
+    attrs = to_cart_item(issue)
+    return nil if duplicate?(cart, attrs)
+
+    cart.add_item(attrs)
+  end
+
+  private
+
+  def duplicate?(cart, attrs)
+    cart.items.any? do |cart_item|
+      item = cart_item.with_indifferent_access
+      item[:item_type] == attrs[:item_type] &&
+        item[:issue_id].to_i == attrs[:issue_id].to_i &&
+        BigDecimal(item[:amount].to_s) == amount
+    end
+  end
+end

app/models/github/event.rb

@@ -81,6 +81,7 @@ def self.process_event(event)
     when 'IssueCommentEvent'
       issue = issue(event['payload']['issue'], tracker: repo)
       comment(event['payload']['comment'], issue: issue)
+      Github::BountyIntent.queue_from_comment(event['payload']['comment'], issue: issue, actor: actor)
 
     when 'PullRequestEvent'
       # NOTE: we can NOT pass in the pull_request here because it doesn't have the right remote_id for issue

spec/models/github/bounty_intent_spec.rb

@@ -0,0 +1,35 @@
+require 'rails_helper'
+
+RSpec.describe Github::BountyIntent do
+  describe '.extract' do
+    it 'extracts GitHub comment bounty amounts' do
+      amounts = described_class.extract('Please add $+20 to this issue and +$5 more.').map(&:amount)
+
+      expect(amounts).to eq([BigDecimal('20'), BigDecimal('5')])
+    end
+
+    it 'ignores comments without bounty amounts' do
+      expect(described_class.extract('Looks good to me')).to eq([])
+    end
+  end
+
+  describe '.queue_from_comment' do
+    let(:person) { create(:person) }
+    let(:actor) { create(:linked_account_github, person: person) }
+    let(:issue) { create(:issue) }
+
+    it 'queues a bounty in the commenter shopping cart' do
+      described_class.queue_from_comment({ 'body' => '$+10' }, issue: issue, actor: actor)
+
+      expect(person.shopping_cart.items).to include(
+        hash_including('item_type' => 'Bounty', 'amount' => '10.0', 'currency' => 'USD', 'issue_id' => issue.id)
+      )
+    end
+
+    it 'does not queue duplicate pending bounty intents' do
+      2.times { described_class.queue_from_comment({ 'body' => '$+10' }, issue: issue, actor: actor) }
+
+      expect(person.shopping_cart.items.count).to eq(1)
+    end
+  end
+end