Feature: expect message using `expect` Use `expect(object).to receive(:message)` to set an expectation that `object` should receive the message `:message` before the example is completed. Note: You can use `expect_any_instance_of` when you don't have a reference to the object that receives a message in your test. For more information, see the message_expectations/expect_any_instance_of feature. Scenario: expect a message Given a file named "spec/account_spec.rb" with: """ruby require "account" describe Account do context "when closed" do it "logs an account closed message" do logger = double("logger") account = Account.new logger expect(logger).to receive(:account_closed) account.close end end end """ And a file named "lib/account.rb" with: """ruby Account = Struct.new(:logger) do def close logger.account_closed end end """ When I run `rspec spec/account_spec.rb` Then the output should contain "1 example, 0 failures" Scenario: expect a message with an argument Given a file named "spec/account_spec.rb" with: """ruby require "account" describe Account do context "when closed" do it "logs an account closed message" do logger = double("logger") account = Account.new logger expect(logger).to receive(:account_closed).with(account) account.close end end end """ And a file named "lib/account.rb" with: """ruby Account = Struct.new(:logger) do def close logger.account_closed(self) end end """ When I run `rspec spec/account_spec.rb` Then the output should contain "1 example, 0 failures" Scenario: provide a return value Given a file named "spec/message_expectation_spec.rb" with: """ruby describe "a message expectation with a return value" do context "specified in a block" do it "returns the specified value" do object = double("object") expect(object).to receive(:message) { :return_value } object.message.should eq(:return_value) end end context "specified with and_return" do it "returns the specified value" do object = double("object") expect(object).to receive(:message).and_return(:return_value) object.message.should eq(:return_value) end end end """ When I run `rspec spec/message_expectation_spec.rb` Then the output should contain "2 examples, 0 failures" Scenario: expect a specific number of calls Given a file named "spec/message_count_spec.rb" with: """ruby describe "a message expectation with a count" do it "passes if the expected number of calls happen" do string = "hi" expect(string).to receive(:length).exactly(3).times 3.times { string.length } end end """ When I run `rspec spec/message_count_spec.rb` Then the output should contain "1 example, 0 failures"