Add review coverage model

app/models/events/pull_request.rb

@@ -52,6 +52,7 @@ class PullRequest < ApplicationRecord
                                      dependent: :destroy, inverse_of: :pull_request
     has_many :events, as: :handleable, dependent: :destroy
     has_one :merge_time, dependent: :destroy
+    has_one :review_coverage, dependent: :destroy
 
     validates :state, inclusion: { in: states.keys }
     validates :github_id,
@@ -65,13 +66,5 @@ class PullRequest < ApplicationRecord
               :locked,
               inclusion: { in: [true, false] }
     validates :github_id, uniqueness: true, strict: PullRequests::GithubUniquenessError
-
-    after_validation :build_merge_time, on: :update, if: :merged_at_changed?
-
-    private
-
-    def build_merge_time
-      Builders::MergeTime.call(self)
-    end
   end
 end

app/models/metric_definition.rb

@@ -19,7 +19,8 @@ class MetricDefinition < ApplicationRecord
                defect_escape_rate: 'defect_escape_rate',
                pull_request_size: 'pull_request_size',
                development_cycle: 'development_cycle',
-               planned_to_done: 'planned_to_done' }
+               planned_to_done: 'planned_to_done',
+               review_coverage: 'review_coverage' }
 
   validates :code, uniqueness: true
   validates :name, presence: true, uniqueness: true

app/models/review_coverage.rb

@@ -0,0 +1,32 @@
+# == Schema Information
+#
+# Table name: review_coverages
+#
+#  id                        :bigint           not null, primary key
+#  coverage_percentage       :decimal(, )      not null
+#  deleted_at                :datetime
+#  files_with_comments_count :integer          not null
+#  total_files_changed       :integer          not null
+#  created_at                :datetime         not null
+#  updated_at                :datetime         not null
+#  pull_request_id           :bigint           not null
+#
+# Indexes
+#
+#  index_review_coverages_on_pull_request_id  (pull_request_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (pull_request_id => events_pull_requests.id)
+#
+
+class ReviewCoverage < ApplicationRecord
+  acts_as_paranoid
+
+  belongs_to :pull_request, class_name: 'Events::PullRequest'
+
+  validates :total_files_changed, :files_with_comments_count, presence: true
+  validates :pull_request_id, uniqueness: true
+  validates :total_files_changed, :files_with_comments_count,
+            numericality: { greater_than_or_equal_to: 0 }
+end

app/services/action_handlers/pull_request.rb

@@ -16,7 +16,11 @@ def open
     end
 
     def merged
-      @entity.update!(merged_at: Time.current)
+      ActiveRecord::Base.transaction do
+        @entity.update!(merged_at: Time.current)
+        Builders::MergeTime.call(@entity)
+        Builders::ReviewCoverage.call(@entity)
+      end
     end
 
     def closed

app/services/builders/review_coverage.rb

@@ -0,0 +1,35 @@
+module Builders
+  class ReviewCoverage < BaseService
+    def initialize(pull_request)
+      @pull_request = pull_request
+    end
+
+    def call
+      ::ReviewCoverage.create!(
+        pull_request: @pull_request,
+        total_files_changed: total_files,
+        files_with_comments_count: files_with_comments_count,
+        coverage_percentage: coverage_percentage
+      )
+    end
+
+    private
+
+    def total_files
+      @total_files ||= github_client.files.count
+    end
+
+    def files_with_comments_count
+      @files_with_comments_count ||=
+        github_client.comments.map { |comment| { filename: comment[:path] } }.uniq.count
+    end
+
+    def coverage_percentage
+      (files_with_comments_count.to_f / total_files).round(2)
+    end
+
+    def github_client
+      @github_client ||= GithubClient::PullRequest.new(@pull_request)
+    end
+  end
+end

app/services/github_client/pull_request.rb

@@ -16,10 +16,29 @@ def get
     def files
       url = "repositories/#{repository.github_id}/pulls/#{pull_request.number}/files"
       get_all_paginated_items(url, MAX_FILES_PER_PAGE)
+    rescue Faraday::Error => exception
+      handle_exception(exception)
+      []
+    end
+
+    def comments
+      url = "repos/#{repository.full_name}/pulls/#{pull_request.number}/comments"
+      get_all_paginated_items(url, MAX_FILES_PER_PAGE)
+    rescue Faraday::Error => exception
+      handle_exception(exception)
+      []
     end
 
     private
 
     attr_reader :pull_request
+
+    def handle_exception(exception)
+      Honeybadger.notify(exception)
+      Rails.logger.error(
+        "Failed to retrieve data for pull request #{pull_request.number} " \
+        "from repository #{repository.full_name}: #{exception.message}"
+      )
+    end
   end
 end

db/migrate/20250429002929_create_review_coverages.rb

@@ -0,0 +1,13 @@
+class CreateReviewCoverages < ActiveRecord::Migration[7.1]
+  def change
+    create_table :review_coverages do |t|
+      t.references :pull_request, null: false, foreign_key: { to_table: :events_pull_requests }
+      t.integer :total_files_changed, null: false
+      t.integer :files_with_comments_count, null: false
+      t.decimal :coverage_percentage, null: false
+      t.datetime :deleted_at
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20250430151601_add_review_coverage_to_metric_name_type.rb

@@ -0,0 +1,18 @@
+class AddReviewCoverageToMetricNameType < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def up
+    execute <<-SQL
+      ALTER TYPE metric_name ADD VALUE 'review_coverage';
+    SQL
+  end
+
+  def down
+    execute <<-SQL
+      ALTER TYPE metric_name RENAME TO metric_name_old;
+      CREATE TYPE metric_name AS ENUM ('review_turnaround', 'blog_visits', 'merge_time', 'blog_post_count', 'open_source_visits', 'defect_escape_rate', 'pull_request_size', 'development_cycle');
+      ALTER TABLE metrics ALTER COLUMN name TYPE metric_name USING name::text::metric_name;
+      DROP TYPE metric_name_old;
+    SQL
+  end
+end

db/seeds.rb

@@ -151,4 +151,5 @@
   MetricDefinition.create!(code: :pull_request_size, explanation: 'Measures the lines of code added by each PR. The smaller the PR, the easier it is to review, which speeds up the review process..', name: 'PR Size')
   MetricDefinition.create!(code: :development_cycle, explanation: 'It measures how much time the team spends working on a task.', name: 'Development Cycle')
   MetricDefinition.create!(code: :planned_to_done, explanation: 'The planned-to-done ratio measures what percentage of the tasks you set out for your team were completed satisfactorily.', name: 'Planned to Done Ratio')
+  MetricDefinition.create!(code: :review_coverage, explanation: 'Measures the percentage of files in a pull request that have received review comments.', name: 'Review Coverage')
 end

db/structure.sql

@@ -128,7 +128,8 @@ CREATE TYPE public.metric_name AS ENUM (
     'defect_escape_rate',
     'pull_request_size',
     'development_cycle',
-    'planned_to_done'
+    'planned_to_done',
+    'review_coverage'
 );
 
 
@@ -1294,6 +1295,41 @@ CREATE SEQUENCE public.repositories_id_seq
 ALTER SEQUENCE public.repositories_id_seq OWNED BY public.repositories.id;
 
 
+--
+-- Name: review_coverages; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.review_coverages (
+    id bigint NOT NULL,
+    pull_request_id bigint NOT NULL,
+    total_files_changed integer NOT NULL,
+    files_with_comments_count integer NOT NULL,
+    coverage_percentage numeric NOT NULL,
+    deleted_at timestamp(6) without time zone,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL
+);
+
+
+--
+-- Name: review_coverages_id_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+CREATE SEQUENCE public.review_coverages_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: review_coverages_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: -
+--
+
+ALTER SEQUENCE public.review_coverages_id_seq OWNED BY public.review_coverages.id;
+
+
 --
 -- Name: review_requests; Type: TABLE; Schema: public; Owner: -
 --
@@ -1711,6 +1747,13 @@ ALTER TABLE ONLY public.products ALTER COLUMN id SET DEFAULT nextval('public.pro
 ALTER TABLE ONLY public.repositories ALTER COLUMN id SET DEFAULT nextval('public.repositories_id_seq'::regclass);
 
 
+--
+-- Name: review_coverages id; Type: DEFAULT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.review_coverages ALTER COLUMN id SET DEFAULT nextval('public.review_coverages_id_seq'::regclass);
+
+
 --
 -- Name: review_requests id; Type: DEFAULT; Schema: public; Owner: -
 --
@@ -2001,6 +2044,14 @@ ALTER TABLE ONLY public.repositories
     ADD CONSTRAINT repositories_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: review_coverages review_coverages_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.review_coverages
+    ADD CONSTRAINT review_coverages_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: review_requests review_requests_pkey; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -2463,6 +2514,13 @@ CREATE INDEX index_repositories_on_language_id ON public.repositories USING btre
 CREATE INDEX index_repositories_on_product_id ON public.repositories USING btree (product_id);
 
 
+--
+-- Name: index_review_coverages_on_pull_request_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_review_coverages_on_pull_request_id ON public.review_coverages USING btree (pull_request_id);
+
+
 --
 -- Name: index_review_requests_on_owner_id; Type: INDEX; Schema: public; Owner: -
 --
@@ -2660,6 +2718,13 @@ ALTER TABLE ONLY public.events_pushes
     ADD CONSTRAINT fk_rails_3f633d82fd FOREIGN KEY (repository_id) REFERENCES public.repositories(id);
 
 
+--
+-- Name: review_coverages fk_rails_40af85f049; Type: FK CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.review_coverages
+    ADD CONSTRAINT fk_rails_40af85f049 FOREIGN KEY (pull_request_id) REFERENCES public.events_pull_requests(id);
+
 
 --
 -- Name: events_pushes fk_rails_4767e99b87; Type: FK CONSTRAINT; Schema: public; Owner: -
@@ -2936,6 +3001,8 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20250430195700'),
 ('20250430195657'),
 ('20250430195652'),
+('20250430151601'),
+('20250429002929'),
 ('20240829142623'),
 ('20240627133952'),
 ('20221228121949'),

lib/tasks/review_coverage_backfill.rake

@@ -0,0 +1,23 @@
+namespace :review_coverage do
+  desc 'Backfill review coverage for merged pull requests'
+  task backfill: :environment do
+    puts 'Starting review coverage backfill...'
+
+    pull_requests = Events::PullRequest
+                    .where.not(merged_at: nil)
+                    .where.not(id: ReviewCoverage.select(:pull_request_id))
+                    .where(created_at: Time.current.beginning_of_year..Time.current)
+
+    total = pull_requests.count
+    puts "Found #{total} pull requests to process"
+
+    pull_requests.find_each do |pull_request|
+      Builders::ReviewCoverage.call(pull_request)
+    rescue StandardError => exception
+      puts "Error processing PR ##{pull_request.number}
+            in repository #{pull_request.repository.id}: #{exception.message}"
+    end
+
+    puts 'Review coverage backfill completed!'
+  end
+end

spec/factories/events/pull_requests.rb

@@ -53,5 +53,26 @@
     repository
 
     association :owner, factory: :user
+
+    trait :merged do
+      state { 'closed' }
+      merged_at { Time.current }
+
+      transient do
+        merge_time { (merged_at - opened_at).to_i }
+      end
+
+      after(:create) do |pull_request, evaluator|
+        create(
+          :merge_time,
+          pull_request: pull_request,
+          value: evaluator.merge_time
+        )
+        create(
+          :review_coverage,
+          pull_request: pull_request
+        )
+      end
+    end
   end
 end

spec/factories/review_coverages.rb

@@ -0,0 +1,30 @@
+# == Schema Information
+#
+# Table name: review_coverages
+#
+#  id                        :bigint           not null, primary key
+#  coverage_percentage       :decimal(, )      not null
+#  deleted_at                :datetime
+#  files_with_comments_count :integer          not null
+#  total_files_changed       :integer          not null
+#  created_at                :datetime         not null
+#  updated_at                :datetime         not null
+#  pull_request_id           :bigint           not null
+#
+# Indexes
+#
+#  index_review_coverages_on_pull_request_id  (pull_request_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (pull_request_id => events_pull_requests.id)
+#
+
+FactoryBot.define do
+  factory :review_coverage do
+    total_files_changed { Faker::Number.between(from: 1, to: 100) }
+    files_with_comments_count { Faker::Number.between(from: 0, to: total_files_changed) }
+    coverage_percentage { (files_with_comments_count.to_f / total_files_changed).round(2) }
+    pull_request
+  end
+end