Project: RSpec Mocks 2.13

Publisher: RSpec

Stub Undefined Constant

Use stub_const to stub constants. When the constant is not already defined,
all the necessary intermediary modules will be dynamically created. When the
example completes, the intermediary module constants will be removed to return
the constant state to how it started.

Scenarios

Stub top-level constant

Given

a file named "stub_const_spec.rb" with:

describe "stubbing FOO" do
  it "can stub undefined constant FOO" do
    stub_const("FOO", 5)
    FOO.should eq(5)
  end

  it "undefines the constant when the example completes" do
    expect { FOO }.to raise_error(NameError)
  end
end

When

I run rspec stub_const_spec.rb

Then

the examples should all pass

Stub nested constant

Given

a file named "stub_const_spec.rb" with:

module MyGem
  class SomeClass
  end
end

module MyGem
  describe SomeClass do
    it "can stub an arbitrarily deep constant that is undefined" do
      defined?(SomeClass::A).should be_false
      stub_const("MyGem::SomeClass::A::B::C", 3)
      SomeClass::A::B::C.should eq(3)
      SomeClass::A.should be_a(Module)
    end

    it 'undefines the intermediary constants that were dynamically created' do
      defined?(SomeClass).should be_true
      defined?(SomeClass::A).should be_false
    end
  end
end

When

I run rspec stub_const_spec.rb

Then

the examples should all pass

Last published about 7 years ago by myronmarston.

Stub Undefined Constant

RSpec Mocks settings