Add GithubPullRequests service

- Receives pull_request event
- Requires a personal OAuth token
- Updates status and/or adds a comment depending on configuration

Author: pbrisbin

lib/cc/service.rb

@@ -30,7 +30,7 @@ def self.load_services
 
     attr_reader :event, :config, :payload
 
-    ALL_EVENTS = %w[test unit coverage quality vulnerability snapshot]
+    ALL_EVENTS = %w[test unit coverage quality vulnerability snapshot pull_request]
 
     # Tracks the defined services.
     def self.services

lib/cc/services/github_pull_requests.rb

@@ -0,0 +1,92 @@
+class CC::Service::GitHubPullRequests < CC::Service
+  class Config < CC::Service::Config
+    attribute :oauth_token, String,
+      label: "OAuth Token",
+      description: "A personal OAuth token with permissions for the repo"
+    attribute :update_status, Boolean,
+      label: "Update status?",
+      description: "Update the pull request status after analyzing?"
+    attribute :add_comment, Boolean,
+      label: "Add a comment?",
+      description: "Comment on the pull request after analyzing?"
+
+    validates :oauth_token, presence: true
+  end
+
+  self.title = "GitHub Pull Requests"
+  self.description = "Update pull requests on on GitHub"
+
+  BASE_URL = "https://api.github.com"
+  BODY_REGEX = %r{<b>Code Climate</b> has <a href=".*">analyzed this pull request</a>}
+  COMMENT_BODY = '<img src="https://codeclimate.com/favicon.png" width="20" height="20" />&nbsp;<b>Code Climate</b> has <a href="%s">analyzed this pull request</a>.'
+
+  def receive_pull_request
+    setup_http
+
+    case @payload["state"]
+    when "pending"
+      update_status("pending", "Code Climate is analyzing this code.")
+    when "success"
+      add_comment
+      update_status("success", "Code Climate has analyzed this pull request.")
+    end
+  end
+
+private
+
+  def update_status(state, description)
+    if config.update_status
+      body = {
+        state:       state,
+        description: description,
+        target_url:  @payload["details_url"],
+      }.to_json
+
+      http_post(status_url, body)
+    end
+  end
+
+  def add_comment
+    if config.add_comment && !comment_present?
+      body = {
+        body: COMMENT_BODY % @payload["compare_url"]
+      }.to_json
+
+      http_post(comments_url, body)
+    end
+  end
+
+  def comment_present?
+    response = http_get(comments_url)
+    comments = JSON.parse(response.body)
+
+    comments.any? { |comment| comment["body"] =~ BODY_REGEX }
+  end
+
+  def setup_http
+    http.headers["Content-Type"]  = "application/json"
+    http.headers["Authorization"] = "token #{config.oauth_token}"
+    http.headers["User-Agent"]    = "Code Climate"
+  end
+
+  def status_url
+    "#{BASE_URL}/repos/#{github_slug}/statuses/#{commit_sha}"
+  end
+
+  def comments_url
+    "#{BASE_URL}/repos/#{github_slug}/issues/#{number}/comments"
+  end
+
+  def github_slug
+    @payload.fetch("github_slug")
+  end
+
+  def commit_sha
+    @payload.fetch("commit_sha")
+  end
+
+  def number
+    @payload.fetch("number")
+  end
+
+end

pull_request_test.rb

@@ -0,0 +1,38 @@
+#!/usr/bin/env ruby
+#
+# Ad-hoc script for updating a pull request using our service.
+#
+# Usage:
+#
+#   $ OAUTH_TOKEN="..." bundle exec ruby pull_request_test.rb
+#
+###
+require 'cc/services'
+CC::Service.load_services
+
+class WithResponseLogging
+  def initialize(invocation)
+    @invocation = invocation
+  end
+
+  def call
+    @invocation.call.tap { |r| p r }
+  end
+end
+
+service = CC::Service::GitHubPullRequests.new({
+  oauth_token:   ENV.fetch("OAUTH_TOKEN"),
+  update_status: true,
+  add_comment:   true,
+}, {
+  name:        "pull_request",
+  # https://github.com/codeclimate/nillson/pull/33
+  state:       "success",
+  github_slug: "codeclimate/nillson",
+  number:      33,
+  commit_sha:  "986ec903b8420f4e8c8d696d8950f7bd0667ff0c"
+})
+
+CC::Service::Invocation.new(service) do |i|
+  i.wrap(WithResponseLogging)
+end

test/github_pull_requests_test.rb

@@ -0,0 +1,95 @@
+require File.expand_path('../helper', __FILE__)
+
+class TestGitHubPullRequests < CC::Service::TestCase
+  def test_pull_request_status_pending
+    expect_status_update("pbrisbin/foo", "abc123", {
+      "state"       => "pending",
+      "description" => /is analyzing/,
+    })
+
+    receive_pull_request({ update_status: true }, {
+      github_slug: "pbrisbin/foo",
+      commit_sha:  "abc123",
+      state:       "pending",
+    })
+  end
+
+  def test_pull_request_status_success
+    expect_status_update("pbrisbin/foo", "abc123", {
+      "state"       => "success",
+      "description" => /has analyzed/,
+    })
+
+    receive_pull_request({ update_status: true }, {
+      github_slug: "pbrisbin/foo",
+      commit_sha:  "abc123",
+      state:       "success",
+    })
+  end
+
+  def test_pull_request_comment
+    stub_existing_comments("pbrisbin/foo", 1, %w[Hey Yo])
+
+    expect_comment("pbrisbin/foo", 1, %r{href="http://example.com">analyzed})
+
+    receive_pull_request({ add_comment: true }, {
+      github_slug: "pbrisbin/foo",
+      number:      1,
+      state:       "success",
+      compare_url: "http://example.com",
+    })
+  end
+
+  def test_pull_request_comment_already_present
+    stub_existing_comments("pbrisbin/foo", 1, [
+      '<b>Code Climate</b> has <a href="">analyzed this pull request</a>'
+    ])
+
+    # With no POST expectation, test will fail if request is made.
+
+    receive_pull_request({ add_comment: true }, {
+      github_slug: "pbrisbin/foo",
+      number:      1,
+      state:       "success",
+    })
+  end
+
+private
+
+  def expect_status_update(repo, commit_sha, params)
+    @stubs.post "repos/#{repo}/statuses/#{commit_sha}" do |env|
+      assert_equal "token 123", env[:request_headers]["Authorization"]
+
+      body = JSON.parse(env[:body])
+
+      params.each do |k, v|
+        assert v === body[k],
+          "Unexpected value for #{k}. #{v.inspect} !== #{body[k].inspect}"
+      end
+    end
+  end
+
+  def stub_existing_comments(repo, number, bodies)
+    body = bodies.map { |b| { body: b } }.to_json
+
+    @stubs.get("repos/#{repo}/issues/#{number}/comments") { [200, {}, body] }
+  end
+
+  def expect_comment(repo, number, content)
+    @stubs.post "repos/#{repo}/issues/#{number}/comments" do |env|
+      body = JSON.parse(env[:body])
+      assert_equal "token 123", env[:request_headers]["Authorization"]
+      assert content === body["body"],
+        "Unexpected comment body. #{content.inspect} !== #{body["body"].inspect}"
+    end
+  end
+
+  def receive_pull_request(config, event_data)
+    receive(
+      CC::Service::GitHubPullRequests,
+      { oauth_token: "123" }.merge(config),
+      { name: "pull_request" }.merge(event_data)
+    )
+  end
+
+end