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Follow along at: http://bit.ly/rspec_magic

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Everybody loves RSpec

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No content

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March, 2011

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RSpec is complicated

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While I think the benefits are discernable…

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This is mostly about the complicated

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Why is RSpec complicated? •RSpec is expressive •And very flexible •And it’s a big library

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How flexible is RSpec?

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With about 10 lines of configuration

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This flexible… RSpec.! Hotel do
 " "works" do
 #(1 + 1).to ❤(2)
 end
 end

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RSpec: It’s not actually Magic Noel Rappin Table XI

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We’re going to look at RSpec source code

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Please don’t avert your eyes

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Why talk about RSpec internals?

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Talks should tell a story

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Once upon a time, there was a test… require 'rails_helper'
 
 RSpec.describe Name do
 it "produces a sort name" do
 name = Name.new("Noel", "Rappin")
 expect(name.sort_name).to eq("Rappin, Noel")
 end
 end

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RSpec with Parentheses require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end

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Key RSpec words require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end

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RSpec power words describe it expect to(something)

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RSpec power words describe it expect to(something) ExampleGroup Example ExpectationTarget Matcher

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require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end

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require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end Example Group

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require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end Example Group Example

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require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end Example Group Example ExpectationTarget

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require 'rails_helper'
 
 RSpec.describe(Name) do
 self.it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 self.expect(name.sort_name).to(self.eq(“Rappin, Noel”))
 end
 end Example Group Example ExpectationTarget Matcher

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Example Group • Created by describe or context • Arguments are a description, metadata, and block • Creates an anonymous subclass of ExampleGroup • Executes the block in the context of the class RSpec.describe Name, metadata: true do
 #stuff
 end

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Creating an ExampleGroup def self.subclass(parent, description, args, &example_group_block)
 subclass = Class.new(parent)
 subclass.set_it_up(description, *args, &example_group_block)
 subclass.module_exec(&example_group_block) if example_group_block
 MemoizedHelpers.define_helpers_on(subclass)
 subclass
 end

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Example Group Subclass def self.subclass(parent, description, args, &example_group_block)
 subclass = Class.new(parent)
 subclass.set_it_up(description, *args, &example_group_block)
 subclass.module_exec(&example_group_block) if example_group_block
 MemoizedHelpers.define_helpers_on(subclass)
 subclass
 end

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Setup (configure mock package) def self.subclass(parent, description, args, &example_group_block)
 subclass = Class.new(parent)
 subclass.set_it_up(description, *args, &example_group_block)
 subclass.module_exec(&example_group_block) if example_group_block
 MemoizedHelpers.define_helpers_on(subclass)
 subclass
 end

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Setup (configure mock package) def self.subclass(parent, description, args, &example_group_block)
 subclass = Class.new(parent)
 subclass.set_it_up(description, *args, &example_group_block)
 subclass.module_exec(&example_group_block) if example_group_block
 MemoizedHelpers.define_helpers_on(subclass)
 subclass
 end

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Setup (configure mock package) def self.subclass(parent, description, args, &example_group_block)
 subclass = Class.new(parent)
 subclass.set_it_up(description, *args, &example_group_block)
 subclass.module_exec(&example_group_block) if example_group_block
 MemoizedHelpers.define_helpers_on(subclass)
 subclass
 end

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What is module_exec? class Thing
 end
 
 Thing.module_exec(arg) do |arg|
 def hello() "Hello there!" end
 end 
 puts Thing.new.hello()

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Minimal RSpec with Parentheses require 'rails_helper'
 
 <>.module_exec do
 it(“produces a sort name”) do
 name = Name.new("Noel", "Rappin")
 expect(name.sort_name).to(eq(“Rappin, Noel”))
 end
 end

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Example • Created by it, example, specify — instance methods of ExampleGroup • Arguments are description, metadata, and a block • Assigns the example to an array class attribute of the ExampleGroup it(“produces a sort name”) do
 #stuff
 end

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Creating an Example desc, *args = *all_args
 options = Metadata.build_hash_from(args) unless block
 options.update(:skip => RSpec::Core::Pending::NOT_YET_IMPLEMENTED) end options.update(extra_options)
 examples << RSpec::Core::Example.new(self, desc, options, block)
 examples.last

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Creating an Example desc, *args = *all_args
 options = Metadata.build_hash_from(args) unless block
 options.update(:skip => RSpec::Core::Pending::NOT_YET_IMPLEMENTED) end options.update(extra_options)
 examples << RSpec::Core::Example.new(self, desc, options, block)
 examples.last

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Creating an Example desc, *args = *all_args
 options = Metadata.build_hash_from(args) unless block
 options.update(:skip => RSpec::Core::Pending::NOT_YET_IMPLEMENTED) end options.update(extra_options)
 examples << RSpec::Core::Example.new(self, desc, options, block)
 examples.last

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What happens at run time? •RSpec creates an instance of the anonymous ExampleGroup class •The new instance runs all of its examples

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Running ExampleGroup runs examples ExampleGroup runs each example Example runs

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Running an Example Group def self.run(reporter=RSpec::Core::NullReporter)
 return if RSpec.world.wants_to_quit
 reporter.example_group_started(self)
 should_run_context_hooks = descendant_filtered_examples.any?
 begin
 run_before_context_hooks(new('before(:context) hook')) if should_run_context_hooks
 result_for_this_group = run_examples(reporter)
 results_for_descendants = ordering_strategy.order(children).map { |child| child.run(reporter) }.all?
 result_for_this_group && results_for_descendants
 rescue Pending::SkipDeclaredInExample => ex
 for_filtered_examples(reporter) { |example| example.skip_with_exception(reporter, ex) }
 true
 rescue Exception => ex
 RSpec.world.wants_to_quit = true if fail_fast?
 for_filtered_examples(reporter) { |example| example.fail_with_exception(reporter, ex) }
 false
 ensure
 run_after_context_hooks(new('after(:context) hook')) if should_run_context_hooks
 reporter.example_group_finished(self)
 end
 end

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Running an Example Group def self.run(reporter=RSpec::Core::NullReporter)
 return if RSpec.world.wants_to_quit
 reporter.example_group_started(self)
 should_run_context_hooks = descendant_filtered_examples.any?


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Running an Example Group begin
 run_before_context_hooks(new('before(:context) hook')) if should_run_context_hooks
 result_for_this_group = run_examples(reporter)
 results_for_descendants = ordering_strategy.order(children).map { |child| child.run(reporter) }.all?
 result_for_this_group && results_for_descendants


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Running an Example Group 
 rescue Pending::SkipDeclaredInExample => ex
 for_filtered_examples(reporter) { |example| example.skip_with_exception(reporter, ex) }
 true
 rescue Exception => ex
 RSpec.world.wants_to_quit = true if fail_fast?
 for_filtered_examples(reporter) { |example| example.fail_with_exception(reporter, ex) }
 false


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Running an Example Group 
 ensure
 run_after_context_hooks(new('after(:context) hook')) if should_run_context_hooks
 reporter.example_group_finished(self)
 end
 end

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Running an Example Group def self.run(reporter=RSpec::Core::NullReporter)
 return if RSpec.world.wants_to_quit
 reporter.example_group_started(self)
 should_run_context_hooks = descendant_filtered_examples.any?
 begin
 run_before_context_hooks(new('before(:context) hook')) if should_run_context_hooks
 result_for_this_group = run_examples(reporter)
 results_for_descendants = ordering_strategy.order(children).map { |child| child.run(reporter) }.all?
 result_for_this_group && results_for_descendants
 rescue Pending::SkipDeclaredInExample => ex
 for_filtered_examples(reporter) { |example| example.skip_with_exception(reporter, ex) }
 true
 rescue Exception => ex
 RSpec.world.wants_to_quit = true if fail_fast?
 for_filtered_examples(reporter) { |example| example.fail_with_exception(reporter, ex) }
 false
 ensure
 run_after_context_hooks(new('after(:context) hook')) if should_run_context_hooks
 reporter.example_group_finished(self)
 end
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running Examples def self.run_examples(reporter)
 ordering_strategy.order(filtered_examples).map do |example|
 next if RSpec.world.wants_to_quit
 instance = new(example.inspect_output)
 set_ivars(instance, before_context_ivars)
 succeeded = example.run(instance, reporter)
 RSpec.world.wants_to_quit = true if fail_fast? && !succeeded
 succeeded
 end.all?
 end

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Running One Example • Check that it is not pending • Run before blocks • instance_exec the block in the context of the example group • Raise is the example skips or fails • Run after blocks

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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begin
 run_before_example
 @example_group_instance.instance_exec(self, &@example_block)
 if pending?
 Pending.mark_fixed! self
 raise Pending::PendingExampleFixedError,
 'Expected example to fail since it is pending, but it passed.',
 [location]
 end
 rescue Pending::SkipDeclaredInExample
 # no-op, required metadata has already been set by the `skip`
 # method.
 rescue Exception => e
 set_exception(e)
 ensure
 run_after_example
 finish(reporter)
 end

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Expectations and Matchers

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expect(name.sort_name).to eq("Rappin, Noel”) ExpectationTarget.new(name.sortName)


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An Expectation target responds to “to” and “not_to”

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Which take a matcher as an argument and evaluate the matcher

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A matcher responds to “matches?”

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eq is a built in method of RSpec::Matchers def eq(expected)
 BuiltIn::Eq.new(expected)
 end

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.to(Eq#"Rappin, Noel")

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.to(Eq#"Rappin, Noel”) PositiveExpectationHandler.handle_matcher(“Rappin, Noel”, def match(expected, actual)
 actual == expected
 end

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Let’s look at a fancier trick expect(Name.new("Noel Rappin")).to be_valid

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BE_PREDICATE_REGEX = /^(be_(?:an?_)?)(.*)/
 HAS_REGEX = /^(?:have_)(.*)/
 
 def method_missing(method, *args, &block)
 case method.to_s
 when BE_PREDICATE_REGEX
 BuiltIn::BePredicate.new(method, *args, &block)
 when HAS_REGEX
 BuiltIn::Has.new(method, *args, &block)
 else
 super
 end
 end

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class BePredicate < BaseMatcher
 include BeHelpers
 
 def initialize(*args, &block)
 @expected = parse_expected(args.shift)
 @args = args
 @block = block
 end
 
 def matches?(actual, &block)
 @actual = actual
 @block ||= block
 predicate_accessible? && predicate_matches?
 end
 
 def predicate_accessible?
 actual.respond_to?(predicate) || actual.respond_to?(present_tense_predicate)
 end
 
 def predicate_matches?
 method_name = actual.respond_to?(predicate) ? predicate : present_tense_predicate
 @predicate_matches = actual.__send__(method_name, *@args, &@block)
 end
 end

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 def matches?(actual, &block)
 @actual = actual
 @block ||= block
 predicate_accessible? && predicate_matches?
 end
 
 def predicate_accessible?
 actual.respond_to?(predicate) || actual.respond_to?(present_tense_predicate)
 end
 
 def predicate_matches?
 method_name = actual.respond_to?(predicate) ? predicate : present_tense_predicate
 @predicate_matches = actual.__send__(method_name, *@args, &@block)
 end

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 def matches?(actual, &block)
 @actual = actual
 @block ||= block
 predicate_accessible? && predicate_matches?
 end
 
 def predicate_accessible?
 actual.respond_to?(predicate) || actual.respond_to?(present_tense_predicate)
 end
 
 def predicate_matches?
 method_name = actual.respond_to?(predicate) ? predicate : present_tense_predicate
 @predicate_matches = actual.__send__(method_name, *@args, &@block)
 end

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 def matches?(actual, &block)
 @actual = actual
 @block ||= block
 predicate_accessible? && predicate_matches?
 end
 
 def predicate_accessible?
 actual.respond_to?(predicate) || actual.respond_to?(present_tense_predicate)
 end
 
 def predicate_matches?
 method_name = actual.respond_to?(predicate) ? predicate : present_tense_predicate
 @predicate_matches = actual.__send__(method_name, *@args, &@block)
 end

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 def matches?(actual, &block)
 @actual = actual
 @block ||= block
 predicate_accessible? && predicate_matches?
 end
 
 def predicate_accessible?
 actual.respond_to?(predicate) || actual.respond_to?(present_tense_predicate)
 end
 
 def predicate_matches?
 method_name = actual.respond_to?(predicate) ? predicate : present_tense_predicate
 @predicate_matches = actual.__send__(method_name, *@args, &@block)
 end

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Emoji

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define_example_group_method :example_group
 define_example_group_method :describe
 define_example_group_method :context
 define_example_group_method :xdescribe,
 :skip => "Temporarily skipped with xdescribe"
 define_example_group_method :xcontext,
 :skip => "Temporarily skipped with xcontext"
 define_example_group_method :fdescribe,
 :focus => true
 define_example_group_method :fcontext,
 :focus => true

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define_example_method :specify
 define_example_method :focus, :focus => true
 define_example_method :fexample, :focus => true
 define_example_method :fit, :focus => true
 define_example_method :fspecify, :focus => true
 define_example_method :xexample, :skip => 'Temporarily skipped with xexample'
 define_example_method :xit, :skip => 'Temporarily skipped with xit'
 define_example_method :skip, :skip => true
 define_example_method :pending, :pending => true

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require 'rails_helper'
 
 module RSpec
 module Core
 class ExampleGroup
 define_example_group_method :!
 define_example_method :" end
 end
 
 module Matchers
 def #(value=::RSpec::Expectations::ExpectationTarget::UndefinedValue, &block)
 ::RSpec::Expectations::ExpectationTarget.for(value, block)
 end
 alias_matcher :❤, :eq
 end
 end

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And then… RSpec.! Hotel do
 " "works" do
 #(1 + 1).to ❤(2)
 end
 end

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Mocks

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Simple Mock Example require 'rails_helper'
 
 RSpec.describe Name do
 it "assigns a rating category" do
 user = User.new()
 expect(user).to receive(:credit_rating).and_return(1000)
 expect(user.rating_category).to eq("approved")
 end
 end

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What would this mock need to do? •Ensure the method is not called •Track how often it’s called •Verify that expectations are met

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Ruby Method Lookup path • Singleton class • instance methods of class • Included modules • parent of class • parent’s included modules • and so on…

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Singleton Class class << x def foo #something end end def x.bar #something end x.foo; x.bar

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Key Concepts • Receive is a matcher • Space • Proxy • Method Double Original Object Singleton Class MethodDouble Proxy Space Receive Matcher

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Receive creates a matcher def receive(method_name, &block)
 Matchers::Receive.new(method_name, block)
 end

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Inside the Receive Matcher def setup_expectation(subject, &block)
 warn_if_any_instance("expect", subject)
 @describable = setup_mock_proxy_method_substitute( subject, :add_message_expectation, block)
 end
 alias matches? setup_expectation
 
 def setup_mock_proxy_method_substitute(subject, method, block)
 proxy = ::RSpec::Mocks.space.proxy_for(subject)
 setup_method_substitute(proxy, method, block)
 end

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Inside the Receive Matcher def setup_expectation(subject, &block)
 warn_if_any_instance("expect", subject)
 @describable = setup_mock_proxy_method_substitute( subject, :add_message_expectation, block)
 end
 alias matches? setup_expectation
 
 def setup_mock_proxy_method_substitute(subject, method, block)
 proxy = ::RSpec::Mocks.space.proxy_for(subject)
 setup_method_substitute(proxy, method, block)
 end

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Inside the Receive Matcher def setup_expectation(subject, &block)
 warn_if_any_instance("expect", subject)
 @describable = setup_mock_proxy_method_substitute( subject, :add_message_expectation, block)
 end
 alias matches? setup_expectation
 
 def setup_mock_proxy_method_substitute(subject, method, block)
 proxy = ::RSpec::Mocks.space.proxy_for(subject)
 setup_method_substitute(proxy, method, block)
 end

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Inside the Receive Matcher def setup_expectation(subject, &block)
 warn_if_any_instance("expect", subject)
 @describable = setup_mock_proxy_method_substitute( subject, :add_message_expectation, block)
 end
 alias matches? setup_expectation
 
 def setup_mock_proxy_method_substitute(subject, method, block)
 proxy = ::RSpec::Mocks.space.proxy_for(subject)
 setup_method_substitute(proxy, method, block)
 end

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Proxy •Substitutes the doubled method •Tracks calls

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Proxy adds Expectations def add_message_expectation(method_name, opts={}, &block)
 location = opts.fetch(:expected_from) { CallerFilter.first_non_rspec_line }
 meth_double = method_double_for(method_name)
 
 if null_object? && !block
 meth_double.add_default_stub(@error_generator, @order_group, location, opts) do
 @object
 end
 end
 
 meth_double.add_expectation @error_generator, @order_group, location, opts, &block
 end

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Proxy adds Expectations def add_message_expectation(method_name, opts={}, &block)
 location = opts.fetch(:expected_from) { CallerFilter.first_non_rspec_line }
 meth_double = method_double_for(method_name)
 
 if null_object? && !block
 meth_double.add_default_stub(@error_generator, @order_group, location, opts) do
 @object
 end
 end
 
 meth_double.add_expectation @error_generator, @order_group, location, opts, &block
 end

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Proxy adds Expectations def add_message_expectation(method_name, opts={}, &block)
 location = opts.fetch(:expected_from) { CallerFilter.first_non_rspec_line }
 meth_double = method_double_for(method_name)
 
 if null_object? && !block
 meth_double.add_default_stub(@error_generator, @order_group, location, opts) do
 @object
 end
 end
 
 meth_double.add_expectation @error_generator, @order_group, location, opts, &block
 end

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Method Double def define_proxy_method
 return if @method_is_proxied
 save_original_method!
 definition_target.class_exec( self, method_name, visibility) do |method_double, method_name, visibility|
 define_method(method_name) do |*args, &block|
 method_double.proxy_method_invoked(self, *args, &block)
 end
 __send__(visibility, method_name)
 end
 @method_is_proxied = true
 end
 
 def proxy_method_invoked(_obj, *args, &block)
 @proxy.message_received method_name, *args, &block
 end

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Method Double def define_proxy_method
 return if @method_is_proxied
 save_original_method!
 definition_target.class_exec( self, method_name, visibility) do |method_double, method_name, visibility|
 define_method(method_name) do |*args, &block|
 method_double.proxy_method_invoked(self, *args, &block)
 end
 __send__(visibility, method_name)
 end
 @method_is_proxied = true
 end
 
 def proxy_method_invoked(_obj, *args, &block)
 @proxy.message_received method_name, *args, &block
 end

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Method Double def define_proxy_method
 return if @method_is_proxied
 save_original_method!
 definition_target.class_exec( self, method_name, visibility) do |method_double, method_name, visibility|
 define_method(method_name) do |*args, &block|
 method_double.proxy_method_invoked(self, *args, &block)
 end
 __send__(visibility, method_name)
 end
 @method_is_proxied = true
 end
 
 def proxy_method_invoked(_obj, *args, &block)
 @proxy.message_received method_name, *args, &block
 end

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Method Double def define_proxy_method
 return if @method_is_proxied
 save_original_method!
 definition_target.class_exec( self, method_name, visibility) do |method_double, method_name, visibility|
 define_method(method_name) do |*args, &block|
 method_double.proxy_method_invoked(self, *args, &block)
 end
 __send__(visibility, method_name)
 end
 @method_is_proxied = true
 end
 
 def proxy_method_invoked(_obj, *args, &block)
 @proxy.message_received method_name, *args, &block
 end

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Method Double def define_proxy_method
 return if @method_is_proxied
 save_original_method!
 definition_target.class_exec( self, method_name, visibility) do |method_double, method_name, visibility|
 define_method(method_name) do |*args, &block|
 method_double.proxy_method_invoked(self, *args, &block)
 end
 __send__(visibility, method_name)
 end
 @method_is_proxied = true
 end
 
 def proxy_method_invoked(_obj, *args, &block)
 @proxy.message_received method_name, *args, &block
 end

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Expectations are verified after an example is torn down

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See also http://rspec.info/documentation/

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Noel Rappin Table XI @noelrap http://www.pragprog.com/book/nrtest2 (test2rappin for 25% off) http://www.noelrappin.com/trdd http://www.noelrappin.com/mstwjs