rspecでよく見た書き方

エラーが発生しないテスト

not_to raise_error

RSpec.describe "#to_s" do it "does not raise" do expect { Object.new.to_s }.not_to raise_error end end

raise_error matcher - Built in matchers - RSpec Expectations - RSpec - Relish

モックでエラーを発生させる

and_raise

RSpec.describe "Making it raise an error" do it "raises the provided exception" do dbl = double allow(dbl).to receive(:foo).and_raise("boom") dbl.foo end end

Raising an error - Configuring responses - RSpec Mocks - RSpec - Relish

モックの引数のチェック

expect(...).to receive(...).with()

RSpec.describe "Using a RSpec matcher" do let(:dbl) { double } before { expect(dbl).to receive(:foo).with(a_collection_containing_exactly(1, 2)) } it "passes when the args match" do dbl.foo([2, 1]) end it "fails when the args do not match" do dbl.foo([1, 3]) end end

Matching arguments - Setting constraints - RSpec Mocks - RSpec - Relish

メソッドが実行された回数

expect(...).to have_received(...).exactly(...).times

class Account attr_accessor :logger def open logger.account_opened end end describe Account do context "when opened" do it "logger#account_opened was called once" do logger = double("logger") account = Account.new account.logger = logger logger.should_receive(:account_opened).exactly(3).times account.open account.open account.open end end end

receive counts - Message expectations - RSpec Mocks - RSpec - Relish

一つのit内で複数のexpectを実行

aggregate_failures

require 'client' RSpec.describe Client do after do # this should be appended to failure list expect(false).to be(true), "after hook failure" end around do |ex| ex.run # this should also be appended to failure list expect(false).to be(true), "around hook failure" end it "returns a successful response" do response = Client.make_request aggregate_failures "testing response" do expect(response.status).to eq(200) expect(response.headers).to include("Content-Type" => "application/json") expect(response.body).to eq('{"message":"Success"}') end end end

RSpec/MultipleExpectations の対策

Aggregating Failures - Expectation framework integration - RSpec Core - RSpec - Relish

mockの引数などをspyする順番

allow(...).to receive(...) -> subject -> expect(...).to have_received(...) の順番で実行する

RSpec.describe "have_received" do it "passes when the expectation is met" do allow(Invitation).to receive(:deliver) Invitation.deliver expect(Invitation).to have_received(:deliver) end end

誤り

RSpec.describe "have_received" do it "passes when the expectation is met" do allow(Invitation).to receive(:deliver) expect(Invitation).to receive(:deliver).once Invitation.deliver end end

RSpec/MessageSpies の対策

Spies - Basics - RSpec Mocks - RSpec - Relish