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spec_dir = File.expand_path(File.join(File.dirname(__FILE__)))
$LOAD_PATH.unshift(spec_dir)
$LOAD_PATH.uniq!

require 'faraday'
require 'googleauth'
require 'spec_helper'

describe '#get_application_default' do
  before(:example) do
    @key = OpenSSL::PKey::RSA.new(2048)
    @var_name = ServiceAccountCredentials::ENV_VAR
    @orig = ENV[@var_name]
    @home = ENV['HOME']
    @scope = 'https://www.googleapis.com/auth/userinfo.profile'
  end

  after(:example) do
    ENV[@var_name] = @orig unless @orig.nil?
    ENV['HOME'] = @home unless @home == ENV['HOME']
  end

  def cred_json_text
    cred_json = {
      private_key_id: 'a_private_key_id',
      private_key: @key.to_pem,
      client_email: 'app@developer.gserviceaccount.com',
      client_id: 'app.apps.googleusercontent.com',
      type: 'service_account'
    }
    MultiJson.dump(cred_json)
  end

  it 'fails if the GOOGLE_APPLICATION_CREDENTIALS path does not exist' do
    Dir.mktmpdir do |dir|
      key_path = File.join(dir, 'does-not-exist')
      ENV[@var_name] = key_path
      expect { Google::Auth.get_application_default(@scope) }.to raise_error
    end
  end

  it 'succeeds if the GOOGLE_APPLICATION_CREDENTIALS file is valid' do
    Dir.mktmpdir do |dir|
      key_path = File.join(dir, 'my_cert_file')
      FileUtils.mkdir_p(File.dirname(key_path))
      File.write(key_path, cred_json_text)
      ENV[@var_name] = key_path
      expect(Google::Auth.get_application_default(@scope)).to_not be_nil
    end
  end

  it 'succeeds with default file if GOOGLE_APPLICATION_CREDENTIALS is unset' do
    ENV.delete(@var_name) unless ENV[@var_name].nil?
    Dir.mktmpdir do |dir|
      key_path = File.join(dir, '.config',
                           ServiceAccountCredentials::WELL_KNOWN_PATH)
      FileUtils.mkdir_p(File.dirname(key_path))
      File.write(key_path, cred_json_text)
      ENV['HOME'] = dir
      expect(Google::Auth.get_application_default(@scope)).to_not be_nil
    end
  end

  it 'fails without default file or env if not on compute engine' do
    stubs = Faraday::Adapter::Test::Stubs.new do |stub|
      stub.get('/') do |_env|
        [404,
         { 'Metadata-Flavor' => 'Google' },
         '']
      end
    end  # GCE not detected
    Dir.mktmpdir do |dir|
      ENV.delete(@var_name) unless ENV[@var_name].nil? # no env var
      ENV['HOME'] = dir  # no config present in this tmp dir
      c = Faraday.new do |b|
        b.adapter(:test, stubs)
      end
      blk = proc do
        Google::Auth.get_application_default(@scope, connection: c)
      end
      expect(&blk).to raise_error
    end
    stubs.verify_stubbed_calls
  end

  it 'succeeds without default file or env if on compute engine' do
    stubs = Faraday::Adapter::Test::Stubs.new do |stub|
      stub.get('/') do |_env|
        [200,
         { 'Metadata-Flavor' => 'Google' },
         '']
      end
    end  # GCE detected
    Dir.mktmpdir do |dir|
      ENV.delete(@var_name) unless ENV[@var_name].nil? # no env var
      ENV['HOME'] = dir  # no config present in this tmp dir
      c = Faraday.new do |b|
        b.adapter(:test, stubs)
      end
      expect(Google::Auth.get_application_default(@scope,
                                                  connection: c)).to_not be_nil
    end
    stubs.verify_stubbed_calls
  end
end