Implement Event handling

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-07-20 16:07:34 +0200 using RuboCop version 0.73.0.
+# on 2019-07-30 20:31:00 +0200 using RuboCop version 0.73.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -118,7 +118,7 @@ Layout/Tab:
  Exclude:
  - 'config/initializers/omniauth.rb'
 
-# Offense count: 6
+# Offense count: 5
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: final_newline, final_blank_line
@@ -129,7 +129,6 @@ Layout/TrailingBlankLines:
  - 'app/controllers/sessions_controller.rb'
  - 'app/models/user.rb'
  - 'config/initializers/sidekiq.rb'
- - 'config/initializers/voxpupuli.rb'
 
 # Offense count: 2
 # Cop supports --auto-correct.
@@ -140,7 +139,7 @@ Layout/TrailingWhitespace:
 
 # Offense count: 6
 Metrics/AbcSize:
- Max: 111
+ Max: 118
 
 # Offense count: 1
 Metrics/CyclomaticComplexity:
@@ -253,11 +252,11 @@ Style/CommentAnnotation:
  Exclude:
  - 'app/workers/repo_status_worker.rb'
 
-# Offense count: 18
+# Offense count: 23
 Style/Documentation:
  Enabled: false
 
-# Offense count: 59
+# Offense count: 64
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: always, never
@@ -333,15 +332,15 @@ Style/TrailingCommaInArguments:
  Exclude:
  - 'config/initializers/semantic_logger.rb'
 
-# Offense count: 3
+# Offense count: 1
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, MinSize, WordRegex.
 # SupportedStyles: percent, brackets
 Style/WordArray:
  Exclude:
  - 'config/initializers/voxpupuli.rb'
 
-# Offense count: 58
+# Offense count: 69
 # Cop supports --auto-correct.
 # Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
 # URISchemes: http, https

app/controllers/incoming_controller.rb

@@ -2,10 +2,15 @@ class IncomingController < ApplicationController
  skip_before_action :verify_authenticity_token
  skip_before_action :logged_in
 
+ ##
+ # Parse the whole payload from Github and hand it over to the GithubEvent handler
  def github
- # parse the JSON payload, that we get as string, to a hash
  useable_body = JSON.parse(request.body.read).to_h
 
+ # For debug purposes we currently log the requets into Sentry
+ # TODO: Remove this line since the GithubEvent handler reports unknown events.
  Raven.capture_message('Received hook', extra: useable_body)
+
+ GithubEvent.new(useable_body, request.headers['X-GitHub-Event'])
  end
 end

app/lib/github_event.rb

@@ -0,0 +1,19 @@
+class GithubEvent
+ attr_reader :processor
+ delegate :process, to: :processor
+
+ ##
+ # The GithubEvent handler checks which type of event we are dealing with.
+ #
+ # If it is a known event, create a specific handler and let it take care of
+ # the next steps. If not kick off a Sentry error.
+
+ def initialize(payload, type)
+ case type
+ when 'pull_request'
+ @processor = GithubEvent::PullRequest.new(payload)
+ else
+ Raven.capture_message('Unknown Hook Received', extra: useable_body)
+ end
+ end
+end

app/lib/github_event/base.rb

@@ -0,0 +1,13 @@
+class GithubEvent
+ class Base
+ attr_reader :payload
+
+ ##
+ # Receive the payload and start processing it
+
+ def initialize(payload)
+ @payload = payload
+ process
+ end
+ end
+end

app/lib/github_event/pull_request.rb

@@ -0,0 +1,13 @@
+class GithubEvent
+ class PullRequest < GithubEvent::Base
+ attr_reader :gh_pull_request
+
+ ##
+ # Currently we only care about syncing our database with GitHub as our validation
+ # will take action if necessary.
+
+ def process
+ ::PullRequest.update_with_github(payload['pull_request'])
+ end
+ end
+end

app/models/label.rb

@@ -1,3 +1,8 @@
 class Label < ApplicationRecord
  has_and_belongs_to_many :pull_requests
+
+ # TODO: Find out how to manage predefined labels
+ def self.needs_rebase
+ find_or_create_by(name: 'needs-rebase', color: '207de5')
+ end
 end

app/models/pull_request.rb

@@ -1,4 +1,89 @@
 class PullRequest < ApplicationRecord
- belongs_to :repository
+ # It is easier overall to use the GitHub ID for relation management.
+ # It allows us to maintain, update or the Repository or PullRequest without
+ # the counterpart.
+ belongs_to :repository, primary_key: :github_id, foreign_key: :gh_repository_id, inverse_of: :pull_requests
+
  has_and_belongs_to_many :labels
+ after_save :queue_validation
+
+ ##
+ # This method is used for updating our database with the current state of the PullRequest
+ # in GitHub. Therefore it's used with the payload of the webhook content processed by
+ # GithubEvent handler and by the content from the api fetched by the periodic check.
+
+ def self.update_with_github(gh_pull_request)
+ PullRequest.where(github_id: gh_pull_request['id']).first_or_initialize.tap do |pull_request|
+ pull_request.number = gh_pull_request['number']
+ pull_request.state = gh_pull_request['state']
+ pull_request.title = gh_pull_request['title']
+ pull_request.body = gh_pull_request['body']
+ pull_request.gh_created_at = gh_pull_request['created_at']
+ pull_request.gh_updated_at = gh_pull_request['updated_at']
+ pull_request.gh_repository_id = gh_pull_request['base']['repo']['id']
+ pull_request.closed_at = gh_pull_request['closed_at']
+ pull_request.merged_at = gh_pull_request['merged_at']
+ pull_request.mergeable = gh_pull_request['mergeable']
+ pull_request.save
+
+ gh_pull_request['labels'].each do |label|
+ pull_request.labels << Label.find_or_create_by(name: label['name'], color: label['color'])
+ end
+ end
+ end
+
+ ##
+ # Ensure that the Label is attached to the PullRequest
+ #
+ # Therefore ensure that the Label exists for the corresponding repository
+ #
+ # Then ensure the Label is attached to this PullRequest by checking the list
+ # of attached Labels. Unfortunately this seems to be the only option
+ #
+ # If the list does not include the given Label we attach it
+
+ def ensure_label_is_attached(label)
+ repository.ensure_label_exists(label)
+
+ attached_labels = Github.client.labels_for_issue(gh_repository_id, number)
+ return if attached_labels.any? { |attached_label| attached_label['name'] == label.name }
+
+ Github.client.add_labels_to_an_issue(gh_repository_id, number, [label.name])
+ end
+
+ ##
+ # We simply remove the given Label if it exists
+
+ def ensure_label_is_detached(label)
+ Github.client.remove_label(gh_repository_id, number, label.name)
+ end
+
+ ##
+ # if the PullRequest is mergeable we need to check if the 'needs-rebase' Label
+ # is attached. If so, we need to remove it.
+ #
+ # If the PullRequest is not yet mergeable we need to attach the 'needs-rebase'
+ # Label. Therefore we also need to check if the Label exists on repository level.
+ #
+ # The saved_changes variable includes all the stuff that has changed.
+ # We currently don't care about them
+
+ def validate(_saved_changes)
+ if mergeable
+ ensure_label_is_detached(Label.needs_rebase)
+ else
+ repository.ensure_label_exists(Label.needs_rebase)
+ ensure_label_is_attached(label)
+ end
+ end
+
+ private
+
+ ##
+ # Since we want to be a fancy responsive application we to all the validation
+ # stuff which might result in some new querys and api requests asyncronously.
+
+ def queue_validation
+ ValidatePullRequestWorker.perform_async(id, saved_changes) if saved_changes?
+ end
 end

app/models/repository.rb

@@ -1,6 +1,9 @@
 class Repository < ApplicationRecord
- has_many :pull_requests
- has_many :open_pull_requests, -> { where(state: 'open') }, class_name: 'PullRequest'
+ # It is easier overall to use the GitHub ID for relation management.
+ # It allows us to maintain, update or the Repository or PullRequest without
+ # the counterpart.
+ has_many :pull_requests, primary_key: :github_id, foreign_key: :gh_repository_id, inverse_of: :repository
+ has_many :open_pull_requests, -> { where(state: 'open') }, class_name: 'PullRequest', primary_key: :github_id, foreign_key: :gh_repository_id
 
  def actions_needed
  @action_needed ||= begin
@@ -19,25 +22,31 @@ def github_url
  'https://github.com/' + full_name
  end
 
+ ##
+ # Check if the Label exists in the Repository
+ # If we get a 404 create the Label.
+
+ def ensure_label_exists(label)
+ GitHub.client.label(github_id, label.name)
+ rescue Octokit::NotFound
+ Github.client.add_label(github_id, label.name, label.color)
+ end
+
+ ##
+ # Delete the given Label from the Repository
+ #
+ def ensure_label_missing(label)
+ GitHub.client.delete_label!(github_id, label.name)
+ end
+
+ ##
+ # Fetch all open and closed PullRequests and sync our database with them
+ #
  def update_pull_requests
  open_pull_requests = Github.client.pull_requests("voxpupuli/#{name}")
  closed_pull_requests = Github.client.pull_requests("voxpupuli/#{name}", state: :closed)
  (open_pull_requests + closed_pull_requests).each do |gh_pull_request|
- PullRequest.where(repository_id: id, number: gh_pull_request.number).first_or_initialize.tap do |pull_request|
- pull_request.number = gh_pull_request.number
- pull_request.state = gh_pull_request.state
- pull_request.title = gh_pull_request.title
- pull_request.body = gh_pull_request.body
- pull_request.gh_created_at = gh_pull_request.created_at
- pull_request.gh_updated_at = gh_pull_request.updated_at
- pull_request.closed_at = gh_pull_request.closed_at
- pull_request.merged_at = gh_pull_request.merged_at
- pull_request.save
-
- gh_pull_request.labels.each do |label|
- pull_request.labels << Label.find_or_create_by(name: label.name, color: label.color)
- end
- end
+ PullRequest.update_with_github(gh_pull_request)
  end
 
  pull_requests.count

app/workers/validate_pull_request_worker.rb

@@ -0,0 +1,12 @@
+class ValidatePullRequestWorker
+ include Sidekiq::Worker
+
+ ##
+ # As validation may take a bit more time we do it async.
+ # This worker is not meant to hold any logic but only trigger the
+ # validation in its asyncronous context.
+
+ def perform(id, saved_changes)
+ PullRequest.find(id).validate(saved_changes)
+ end
+end

config/initializers/array.rb

@@ -1,5 +1,5 @@
 class Array
  def all_i
- self.map(&:to_i)
+ map(&:to_i)
  end
 end

db/migrate/20190730094710_add_mergeable_and_gh_repo_id_to_pull_requests.rb

@@ -0,0 +1,7 @@
+class AddMergeableAndGhRepoIdToPullRequests < ActiveRecord::Migration[5.2]
+ def change
+ add_column :pull_requests, :mergeable, :boolean
+ add_column :pull_requests, :gh_repository_id, :integer
+ add_column :pull_requests, :github_id, :integer
+ end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_06_20_115024) do
+ActiveRecord::Schema.define(version: 2019_07_30_094710) do
 
  create_table "labels", force: :cascade do |t|
  t.string "name"
@@ -38,6 +38,9 @@
  t.integer "repository_id"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
+ t.boolean "mergeable"
+ t.integer "gh_repository_id"
+ t.integer "github_id"
  t.index ["repository_id"], name: "index_pull_requests_on_repository_id"
  end