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Feature: double handling to_ary
Ruby implicitly sends `to_ary` to all of the objects in an `Array` when the
array receives `flatten`:
[obj].flatten # => obj.to_ary
If `to_ary` raises a `NoMethodError`, Ruby sees that the object can not be coerced
into an array and moves on to the next object.
To support this, an RSpec double will raise a NoMethodError when it receives
`to_ary` _even if it is set `as_null_object`_, unless `to_ary` is explicitly
stubbed.
Scenario: double receiving to_ary
Given a file named "example.rb" with:
"""ruby
describe "#to_ary" do
shared_examples "to_ary" do
it "can be overridden with a stub" do
obj.stub(:to_ary) { :non_nil_value }
obj.to_ary.should be(:non_nil_value)
end
it "supports Array#flatten" do
obj = double('foo')
[obj].flatten.should eq([obj])
end
end
context "sent to a double as_null_object" do
let(:obj) { double('obj').as_null_object }
include_examples "to_ary"
it "returns nil" do
expect( obj.to_ary ).to eq nil
end
end
context "sent to a double without as_null_object" do
let(:obj) { double('obj') }
include_examples "to_ary"
it "raises a NoMethodError" do
expect { obj.to_ary }.to raise_error(NoMethodError)
end
end
end
"""
When I run `rspec example.rb`
Then the examples should all pass
|
