draper/spec/draper/decorator_spec.rb

873 lines
28 KiB
Ruby

require 'spec_helper'
require 'support/shared_examples/view_helpers'
module Draper
describe Decorator do
it_behaves_like "view helpers", Decorator.new(Model.new)
describe "#initialize" do
describe "options validation" do
it "does not raise error on valid options" do
valid_options = {context: {}}
expect{Decorator.new(Model.new, valid_options)}.not_to raise_error
end
it "raises error on invalid options" do
expect{Decorator.new(Model.new, foo: "bar")}.to raise_error ArgumentError, /Unknown key/
end
end
it "sets the object" do
object = Model.new
decorator = Decorator.new(object)
expect(decorator.object).to be object
end
it "stores context" do
context = {some: "context"}
decorator = Decorator.new(Model.new, context: context)
expect(decorator.context).to be context
end
context "when decorating an instance of itself" do
it "applies to the object instead" do
object = Model.new
decorated = Decorator.new(object)
redecorated = Decorator.new(decorated)
expect(redecorated.object).to be object
end
context "with context" do
it "overwrites existing context" do
decorated = Decorator.new(Model.new, context: {some: "context"})
new_context = {other: "context"}
redecorated = Decorator.new(decorated, context: new_context)
expect(redecorated.context).to be new_context
end
end
context "without context" do
it "preserves existing context" do
old_context = {some: "context"}
decorated = Decorator.new(Model.new, context: old_context)
redecorated = Decorator.new(decorated)
expect(redecorated.context).to be old_context
end
end
end
it "decorates other decorators" do
decorated = OtherDecorator.new(Model.new)
redecorated = Decorator.new(decorated)
expect(redecorated.object).to be decorated
end
context "when it has been applied previously" do
it "warns" do
decorated = OtherDecorator.new(Decorator.new(Model.new))
warning_message = nil
allow_any_instance_of(Object).to receive(:warn) { |instance, message| warning_message = message }
expect{Decorator.new(decorated)}.to change{warning_message}
expect(warning_message).to start_with "Reapplying Draper::Decorator"
expect(warning_message).to include caller(1).first
end
it "decorates anyway" do
decorated = OtherDecorator.new(Decorator.new(Model.new))
allow_any_instance_of(Object).to receive(:warn)
redecorated = Decorator.decorate(decorated)
expect(redecorated.object).to be decorated
end
end
end
describe "#context=" do
it "modifies the context" do
decorator = Decorator.new(Model.new, context: {some: "context"})
new_context = {other: "context"}
decorator.context = new_context
expect(decorator.context).to be new_context
end
end
describe ".decorate_collection" do
describe "options validation" do
before { allow(CollectionDecorator).to receive(:new) }
it "does not raise error on valid options" do
valid_options = {with: OtherDecorator, context: {}}
expect{Decorator.decorate_collection([], valid_options)}.not_to raise_error
end
it "raises error on invalid options" do
expect{Decorator.decorate_collection([], foo: "bar")}.to raise_error ArgumentError, /Unknown key/
end
end
context "without a custom collection decorator" do
it "creates a CollectionDecorator using itself for each item" do
object = [Model.new]
expect(CollectionDecorator).to receive(:new).with(object, with: Decorator)
Decorator.decorate_collection(object)
end
it "passes options to the collection decorator" do
options = {with: OtherDecorator, context: {some: "context"}}
expect(CollectionDecorator).to receive(:new).with([], options)
Decorator.decorate_collection([], options)
end
end
context "with a custom collection decorator" do
it "creates a custom collection decorator using itself for each item" do
object = [Model.new]
expect(ProductsDecorator).to receive(:new).with(object, with: ProductDecorator)
ProductDecorator.decorate_collection(object)
end
it "passes options to the collection decorator" do
options = {with: OtherDecorator, context: {some: "context"}}
expect(ProductsDecorator).to receive(:new).with([], options)
ProductDecorator.decorate_collection([], options)
end
end
end
describe ".decorates" do
protect_class Decorator
it "sets .object_class with a symbol" do
Decorator.decorates :product
expect(Decorator.object_class).to be Product
end
it "sets .object_class with a string" do
Decorator.decorates "product"
expect(Decorator.object_class).to be Product
end
it "sets .object_class with a class" do
Decorator.decorates Product
expect(Decorator.object_class).to be Product
end
end
describe ".object_class" do
protect_class ProductDecorator
protect_class Namespaced::ProductDecorator
context "when not set by .decorates" do
it "raises an UninferrableObjectError for a so-named 'Decorator'" do
expect{Decorator.object_class}.to raise_error UninferrableObjectError
end
it "raises an UninferrableObjectError for anonymous decorators" do
expect{Class.new(Decorator).object_class}.to raise_error UninferrableObjectError
end
it "raises an UninferrableObjectError for a decorator without a model" do
SomeDecorator = Class.new(Draper::Decorator)
expect{SomeDecorator.object_class}.to raise_error UninferrableObjectError
end
it "raises an UninferrableObjectError for other naming conventions" do
ProductPresenter = Class.new(Draper::Decorator)
expect{ProductPresenter.object_class}.to raise_error UninferrableObjectError
end
it "infers the object class for '<Model>Decorator'" do
expect(ProductDecorator.object_class).to be Product
end
it "infers the object class for namespaced decorators" do
expect(Namespaced::ProductDecorator.object_class).to be Namespaced::Product
end
context "when an unrelated NameError is thrown" do
it "re-raises that error" do
# Not related to safe_constantize behavior, we just want to raise a NameError inside the function
allow_any_instance_of(String).to receive(:safe_constantize) { SomethingThatDoesntExist }
expect{ProductDecorator.object_class}.to raise_error NameError, /SomethingThatDoesntExist/
end
end
end
end
describe ".object_class?" do
it "returns truthy when .object_class is set" do
allow(Decorator).to receive(:object_class).and_return(Model)
expect(Decorator.object_class?).to be_truthy
end
it "returns false when .object_class is not inferrable" do
allow(Decorator).to receive(:object_class).and_raise(UninferrableObjectError.new(Decorator))
expect(Decorator.object_class?).to be_falsey
end
end
describe '.collection_decorator_class' do
it 'defaults to CollectionDecorator' do
allow_any_instance_of(String).to receive(:safe_constantize) { nil }
expect(ProductDecorator.collection_decorator_class).to be Draper::CollectionDecorator
end
it 'infers collection decorator based on name' do
expect(ProductDecorator.collection_decorator_class).to be ProductsDecorator
end
it 'infers collection decorator base on name for namespeced model' do
expect(Namespaced::ProductDecorator.collection_decorator_class).to be Namespaced::ProductsDecorator
end
end
describe ".decorates_association" do
protect_class Decorator
describe "options validation" do
before { allow(DecoratedAssociation).to receive(:new).and_return(->{}) }
it "does not raise error on valid options" do
valid_options = {with: Class, scope: :sorted, context: {}}
expect{Decorator.decorates_association(:children, valid_options)}.not_to raise_error
end
it "raises error on invalid options" do
expect{Decorator.decorates_association(:children, foo: "bar")}.to raise_error ArgumentError, /Unknown key/
end
end
describe "defines an association method" do
it "creates a DecoratedAssociation" do
options = {with: Class.new, scope: :foo, context: {}}
Decorator.decorates_association :children, options
decorator = Decorator.new(Model.new)
expect(DecoratedAssociation).to receive(:new).with(decorator, :children, options).and_return(->{})
decorator.children
end
it "memoizes the DecoratedAssociation" do
Decorator.decorates_association :children
decorator = Decorator.new(Model.new)
expect(DecoratedAssociation).to receive(:new).once.and_return(->{})
decorator.children
decorator.children
end
it "calls the DecoratedAssociation" do
Decorator.decorates_association :children
decorator = Decorator.new(Model.new)
decorated_association = ->{}
allow(DecoratedAssociation).to receive(:new).and_return(decorated_association)
expect(decorated_association).to receive(:call).and_return(:decorated)
expect(decorator.children).to be :decorated
end
end
end
describe ".decorates_associations" do
protect_class Decorator
it "decorates each of the associations" do
expect(Decorator).to receive(:decorates_association).with(:friends, {})
expect(Decorator).to receive(:decorates_association).with(:enemies, {})
Decorator.decorates_associations :friends, :enemies
end
it "dispatches options" do
options = {with: Class.new, scope: :foo, context: {}}
expect(Decorator).to receive(:decorates_association).with(:friends, options)
expect(Decorator).to receive(:decorates_association).with(:enemies, options)
Decorator.decorates_associations :friends, :enemies, options
end
end
describe "#applied_decorators" do
it "returns a list of decorators applied to a model" do
decorator = ProductDecorator.new(OtherDecorator.new(Decorator.new(Model.new)))
expect(decorator.applied_decorators).to eq [Decorator, OtherDecorator, ProductDecorator]
end
end
describe "#decorated_with?" do
it "checks if a decorator has been applied to a model" do
decorator = ProductDecorator.new(Decorator.new(Model.new))
expect(decorator).to be_decorated_with Decorator
expect(decorator).to be_decorated_with ProductDecorator
expect(decorator).not_to be_decorated_with OtherDecorator
end
end
describe "#decorated?" do
it "returns true" do
decorator = Decorator.new(Model.new)
expect(decorator).to be_decorated
end
end
describe "#object" do
it "returns the wrapped object" do
object = Model.new
decorator = Decorator.new(object)
expect(decorator.object).to be object
expect(decorator.model).to be object
end
it "is aliased to #model" do
object = Model.new
decorator = Decorator.new(object)
expect(decorator.model).to be object
end
end
describe "aliasing object to object class name" do
context "when object_class is inferrable from the decorator name" do
it "aliases object to the object class name" do
object = double
decorator = ProductDecorator.new(object)
expect(decorator.product).to be object
end
end
context "when object_class is set by decorates" do
it "aliases object to the object class name" do
decorator_class = Class.new(Decorator) { decorates Product }
object = double
decorator = decorator_class.new(object)
expect(decorator.product).to be object
end
end
context "when object_class's name is several words long" do
it "underscores the method name" do
stub_const "LongWindedModel", Class.new
decorator_class = Class.new(Decorator) { decorates LongWindedModel }
object = double
decorator = decorator_class.new(object)
expect(decorator.long_winded_model).to be object
end
end
context "when object_class is not set" do
it "does not alias object" do
decorator_class = Class.new(Decorator)
expect(decorator_class.instance_methods).to eq Decorator.instance_methods
end
end
end
describe "#to_model" do
it "returns the decorator" do
decorator = Decorator.new(Model.new)
expect(decorator.to_model).to be decorator
end
end
describe "#to_param" do
it "delegates to the object" do
decorator = Decorator.new(double(to_param: :delegated))
expect(decorator.to_param).to be :delegated
end
end
describe "#present?" do
it "delegates to the object" do
decorator = Decorator.new(double(present?: :delegated))
expect(decorator.present?).to be :delegated
end
end
describe "#blank?" do
it "delegates to the object" do
decorator = Decorator.new(double(blank?: :delegated))
expect(decorator.blank?).to be :delegated
end
end
describe "#to_partial_path" do
it "delegates to the object" do
decorator = Decorator.new(double(to_partial_path: :delegated))
expect(decorator.to_partial_path).to be :delegated
end
end
describe "#to_s" do
it "delegates to the object" do
decorator = Decorator.new(double(to_s: :delegated))
expect(decorator.to_s).to be :delegated
end
end
describe "#inspect" do
it "returns a detailed description of the decorator" do
decorator = ProductDecorator.new(double)
expect(decorator.inspect).to match(/#<ProductDecorator:0x\h+ .+>/)
end
it "includes the object" do
decorator = Decorator.new(double(inspect: "#<the object>"))
expect(decorator.inspect).to include "@object=#<the object>"
end
it "includes the context" do
decorator = Decorator.new(double, context: {foo: "bar"})
expect(decorator.inspect).to include '@context={:foo=>"bar"}'
end
it "includes other instance variables" do
decorator = Decorator.new(double)
decorator.instance_variable_set :@foo, "bar"
expect(decorator.inspect).to include '@foo="bar"'
end
end
describe "#attributes" do
it "returns only the object's attributes that are implemented by the decorator" do
decorator = Decorator.new(double(attributes: {foo: "bar", baz: "qux"}))
allow(decorator).to receive(:foo)
expect(decorator.attributes).to eq({foo: "bar"})
end
end
describe ".model_name" do
it "delegates to the object class" do
allow(Decorator).to receive(:object_class).and_return(double(model_name: :delegated))
expect(Decorator.model_name).to be :delegated
end
end
describe "#==" do
it "works for a object that does not include Decoratable" do
object = Object.new
decorator = Decorator.new(object)
expect(decorator).to eq Decorator.new(object)
end
it "works for a multiply-decorated object that does not include Decoratable" do
object = Object.new
decorator = Decorator.new(object)
expect(decorator).to eq ProductDecorator.new(Decorator.new(object))
end
it "is true when object #== is true" do
object = Model.new
decorator = Decorator.new(object)
other = double(object: Model.new)
expect(object).to receive(:==).with(other).and_return(true)
expect(decorator == other).to be_truthy
end
it "is false when object #== is false" do
object = Model.new
decorator = Decorator.new(object)
other = double(object: Model.new)
expect(object).to receive(:==).with(other).and_return(false)
expect(decorator == other).to be_falsey
end
end
describe "#===" do
it "is true when #== is true" do
decorator = Decorator.new(Model.new)
allow(decorator).to receive(:==) { true }
expect(decorator === :anything).to be_truthy
end
it "is false when #== is false" do
decorator = Decorator.new(Model.new)
allow(decorator).to receive(:==).with(:anything).and_return(false)
expect(decorator === :anything).to be_falsey
end
end
describe "#eql?" do
it "is true when #eql? is true" do
first = Decorator.new('foo')
second = Decorator.new('foo')
expect(first.eql? second).to be
end
it "is false when #eql? is false" do
first = Decorator.new('foo')
second = Decorator.new('bar')
expect(first.eql? second).to_not be
end
end
describe "#hash" do
it "is consistent for equal objects" do
object = Model.new
first = Decorator.new(object)
second = Decorator.new(object)
expect(first.hash == second.hash).to be
end
end
describe ".delegate" do
protect_class Decorator
it "defaults the :to option to :object" do
expect(Object).to receive(:delegate).with(:foo, :bar, to: :object)
Decorator.delegate :foo, :bar
end
it "does not overwrite the :to option if supplied" do
expect(Object).to receive(:delegate).with(:foo, :bar, to: :baz)
Decorator.delegate :foo, :bar, to: :baz
end
end
context "with .delegate_all" do
protect_class Decorator
before { Decorator.delegate_all }
describe "#method_missing" do
it "delegates missing methods that exist on the object" do
decorator = Decorator.new(double(hello_world: :delegated))
expect(decorator.hello_world).to be :delegated
end
it 'delegates `super` to parent class first' do
parent_decorator_class = Class.new(Decorator) do
def hello_world
"parent#hello_world"
end
end
child_decorator_class = Class.new(parent_decorator_class) do
def hello_world
super
end
end
decorator = child_decorator_class.new(double(hello_world: 'object#hello_world'))
expect(decorator.hello_world).to eq 'parent#hello_world'
end
it 'delegates `super` to object if method does not exist on parent class' do
decorator_class = Class.new(Decorator) do
def hello_world
super
end
end
decorator = decorator_class.new(double(hello_world: 'object#hello_world'))
expect(decorator.hello_world).to eq 'object#hello_world'
end
it 'raises `NoMethodError` when `super` is called on for method that does not exist' do
decorator_class = Class.new(Decorator) do
def hello_world
super
end
end
decorator = decorator_class.new(double)
expect{decorator.hello_world}.to raise_error NoMethodError
end
it "allows decorator to decorate different classes of objects" do
decorator_1 = Decorator.new(double)
decorator_2 = Decorator.new(double(hello_world: :delegated))
decorator_2.hello_world
expect(decorator_1.methods).not_to include :hello_world
end
it "passes blocks to delegated methods" do
object = Model.new
allow(object).to receive(:hello_world) { |*args, &block| block.call }
decorator = Decorator.new(object)
expect(decorator.hello_world{:yielded}).to be :yielded
end
it "does not confuse Kernel#Array" do
decorator = Decorator.new(Model.new)
expect(Array(decorator)).to be_an Array
end
it "delegates already-delegated methods" do
object = Class.new{ delegate :bar, to: :foo }.new
allow(object).to receive_messages foo: double(bar: :delegated)
decorator = Decorator.new(object)
expect(decorator.bar).to be :delegated
end
it "does not delegate private methods" do
object = Class.new{ private; def hello_world; end }.new
decorator = Decorator.new(object)
expect{decorator.hello_world}.to raise_error NoMethodError
end
it "does not delegate methods that do not exist on the object" do
decorator = Decorator.new(Model.new)
expect(decorator.methods).not_to include :hello_world
expect{decorator.hello_world}.to raise_error NoMethodError
expect(decorator.methods).not_to include :hello_world
end
context 'when decorator overrides a public method defined on the object with a private' do
let(:decorator_class) do
Class.new(Decorator) do
private
def hello_world
'hello world'
end
end
end
let(:object) { Class.new { def hello_world; end }.new }
it 'does not delegate the public method defined on the object' do
decorator = decorator_class.new(object)
expect{ decorator.hello_world }.to raise_error NoMethodError
end
end
context 'when delegated method has the same name as private method defined on another object' do
let(:decorator_class) { Class.new(Decorator) }
let(:object) { Class.new { def print; end }.new }
it 'delegates the public method defined on the object' do
decorator = decorator_class.new(object)
# `print` private method is defined on `Object`
expect{ decorator.print }.not_to raise_error
end
end
end
context ".method_missing" do
context "without an object class" do
it "raises a NoMethodError on missing methods" do
expect{Decorator.hello_world}.to raise_error NoMethodError
end
end
context "with an object class" do
it "delegates methods that exist on the object class" do
object_class = Class.new
allow(object_class).to receive_messages hello_world: :delegated
allow(Decorator).to receive_messages object_class: object_class
expect(Decorator.hello_world).to be :delegated
end
it "does not delegate methods that do not exist on the object class" do
allow(Decorator).to receive_messages object_class: Class.new
expect{Decorator.hello_world}.to raise_error NoMethodError
end
end
end
describe "#respond_to?" do
it "returns true for its own methods" do
Decorator.class_eval{def hello_world; end}
decorator = Decorator.new(Model.new)
expect(decorator).to respond_to :hello_world
end
it "returns true for the object's methods" do
decorator = Decorator.new(double(hello_world: :delegated))
expect(decorator).to respond_to :hello_world
end
context "with include_private" do
it "returns true for its own private methods" do
Decorator.class_eval{private; def hello_world; end}
decorator = Decorator.new(Model.new)
expect(decorator.respond_to?(:hello_world, true)).to be_truthy
end
it "returns false for the object's private methods" do
object = Class.new{private; def hello_world; end}.new
decorator = Decorator.new(object)
expect(decorator.respond_to?(:hello_world, true)).to be_falsey
end
end
end
describe ".respond_to?" do
context "without a object class" do
it "returns true for its own class methods" do
Decorator.class_eval{def self.hello_world; end}
expect(Decorator).to respond_to :hello_world
end
it "returns false for other class methods" do
expect(Decorator).not_to respond_to :goodnight_moon
end
end
context "with a object class" do
it "returns true for its own class methods" do
Decorator.class_eval{def self.hello_world; end}
allow(Decorator).to receive_messages object_class: Class.new
expect(Decorator).to respond_to :hello_world
end
it "returns true for the object's class methods" do
allow(Decorator).to receive_messages object_class: double(hello_world: :delegated)
expect(Decorator).to respond_to :hello_world
end
end
end
describe "#respond_to_missing?" do
it "allows #method to be called on delegated methods" do
object = Class.new{def hello_world; end}.new
decorator = Decorator.new(object)
expect(decorator.method(:hello_world)).not_to be_nil
end
end
describe ".respond_to_missing?" do
it "allows .method to be called on delegated class methods" do
allow(Decorator).to receive_messages object_class: double(hello_world: :delegated)
expect(Decorator.method(:hello_world)).not_to be_nil
end
end
end
describe "class spoofing" do
it "pretends to be a kind of the object class" do
decorator = Decorator.new(Model.new)
expect(decorator.kind_of?(Model)).to be_truthy
expect(decorator.is_a?(Model)).to be_truthy
end
it "is still a kind of its own class" do
decorator = Decorator.new(Model.new)
expect(decorator.kind_of?(Decorator)).to be_truthy
expect(decorator.is_a?(Decorator)).to be_truthy
end
it "pretends to be an instance of the object class" do
decorator = Decorator.new(Model.new)
expect(decorator.instance_of?(Model)).to be_truthy
end
it "is still an instance of its own class" do
decorator = Decorator.new(Model.new)
expect(decorator.instance_of?(Decorator)).to be_truthy
end
end
describe ".decorates_finders" do
protect_class Decorator
it "extends the Finders module" do
expect(Decorator).not_to be_a_kind_of Finders
Decorator.decorates_finders
expect(Decorator).to be_a_kind_of Finders
end
end
describe "Enumerable hash and equality functionality" do
describe "#uniq" do
it "removes duplicate objects with same decorator" do
object = Model.new
array = [Decorator.new(object), Decorator.new(object)]
expect(array.uniq.count).to eq(1)
end
it "separates different objects with identical decorators" do
array = [Decorator.new('foo'), Decorator.new('bar')]
expect(array.uniq.count).to eq(2)
end
it "separates identical objects with different decorators" do
object = Model.new
array = [Decorator.new(object), OtherDecorator.new(object)]
expect(array.uniq.count).to eq(2)
end
it "distinguishes between an objects and its decorated version" do
object = Model.new
array = [Decorator.new(object), object]
expect(array.uniq.count).to eq(2)
end
end
end
end
end