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Feature: stub a chain of methods
Use the `stub_chain` method to stub a chain of two or more methods in one
statement. Method chains are considered a design smell, but it's not really
the method chain itself that is the problem - it's the dependency chain
represented by a chain of messages to different objects:
foo.get_bar.get_baz
This is a Law of Demeter violation if `get_bar` returns an object other than
`foo`, and `get_baz` returns yet another object.
Fluent interfaces look similar from a caller's perspective, but don't
represent a dependency chain (the caller depends only on the object it is
calling). Consider this common example from Ruby on Rails:
Article.recent.by(current_user)
The `recent` and `by` methods return the same object, so this is not a Law of
Demeter violation.
Scenario: stub a chain of methods
Given a file named "stub_chain_spec.rb" with:
"""ruby
describe "stubbing a chain of methods" do
subject { Object.new }
context "given symbols representing methods" do
it "returns the correct value" do
subject.stub_chain(:one, :two, :three).and_return(:four)
subject.one.two.three.should eq(:four)
end
end
context "given a hash at the end" do
it "returns the correct value" do
subject.stub_chain(:one, :two, :three => :four)
subject.one.two.three.should eq(:four)
end
end
context "given a string of methods separated by dots" do
it "returns the correct value" do
subject.stub_chain("one.two.three").and_return(:four)
subject.one.two.three.should eq(:four)
end
end
end
"""
When I run `rspec stub_chain_spec.rb`
Then the examples should all pass
|
