rspec contexts

README.md

The lets are evaluated from inner-most to outer; but the before are evaluated from outer to inner. With rspec-given the point is to use When as just the bit of code that's "under test". All of the Givens are pre-conditions or setup. That's one of the things I like most about rspec-given, it separates setup code from code under test. The other thing I like about it is the brevity of the individual tests. I find the description on it blocks often quite redundant with the code in the block. I like how Then removes that duplication. Another benefit of rspec-given is that is has natural language failures built in. That's pretty cool.

context_spec.rb

describe "Context Scoping" do
  let(:foo) { "bar" }
  
  before do
    @instance_variable = foo
    @inner_instance_variable = bar # this might blow up because bar isn't defined in outer scope
  end
  
  it "is the outer context" do
    # requires :foo to be defined in the outer context because it's tested against here
    expect(foo).to eq("bar")
    expect(@instance_variable).to eq("bar")
  end
  
  context "changing values" do
    let(:foo) { "foobar" }
    let(:bar) { "barbaz" }

    it "uses the inner context" do
      expect(@instance_variable).to eq("foobar")
      expect(@inner_instance_variable).to eq("barbaz")
    end
  end
end

given_context_spec.rb

describe "Given context scoping" do
  Given(:foo) { "bar" }
  
  When do
    @instance_variable = foo
    @inner_instance_variable = bar
  end
  
  Then { expect(foo).to eq("bar") }
  Then { expect(@instance_variable).to eq("bar")
  
  context "changing values" do
    Given(:foo) { "foobar" }
    
    Then { expect(foo).to eq("foobar") }
    And { expect(@instance_variable).to eq("foobar") }
  end
end