to be used in rpellerin PR

git_utils.rb

# frozen_string_literal: true

# TODO: clean usage of env vars:
#   Heroku should fill our variables, and we should have no references to such variable in our code:
#   HEROKU_TEST_RUN_COMMIT_VERSION / HEROKU_TEST_RUN_COMMIT_VERSION / HEROKU_TEST_RUN_ID
module TestUtils::Helpers::GitUtils
  GITHUB_API = 'https://api.github.com'
  GITHUB_DOCTOLIB_REPOSITORY_PATH = '/repos/doctolib/doctolib'

  # TODO: nice error if git command not found
  def commit_sha1
    # The following constants are for local testing.
    # When run on Heroku, HASH is set to HEROKU_TEST_RUN_COMMIT_VERSION in test.sh
    @_commit_sha1 ||= ENV['HASH'].presence || execute('git rev-parse HEAD')
  end

  def ref_name
    @_ref_name ||= ENV['HEROKU_TEST_RUN_BRANCH'].presence || execute('git rev-parse --abbrev-ref HEAD')
  end

  # Returns a hash with filename as key and patch content as value.
  def pull_request_diff
    @_pull_request_diff ||=
      pull_request_json['files'].map { |file_diff| [file_diff['filename'], file_diff['patch']] }.to_h
  end

  private

  # TODO: this is not a "pull_request", it's a diff with current master.
  # We should not compare with master, but with branch root.
  # Check https://www.git-scm.com/docs/git-rev-parse/1.7.5
  def pull_request_json
    comparison_path = '/compare/master...'
    url = [GITHUB_API, GITHUB_DOCTOLIB_REPOSITORY_PATH, comparison_path, commit_sha1].join
    headers = {
      Accept: 'application/json',
      Authorization: "token #{github_token}",
      'User-Agent': 'HTTParty'
    }
    HTTParty.get(url, { headers: headers })
  end

  # TODO: nice error if this env var is not defined
  def github_token
    ENV['GITHUB_ACCESS_TOKEN']
  end

  def execute(command)
    %x(#{command} 2>/dev/null || true).strip
  end
end