After should only be added if the step is used in the current scenario

[squeedee]

Current behavior

var _ = Describe("Too many afters", func() {
	steps := NewSteps()

	var (
		oneCounter int = 0
		twoCounter int = 0
	)
	Scenario("first scenario", func() {
		steps.When("thing 1 is run")
	})

	Scenario("second scenario", func() {
		steps.When("thing 2 is run")
	})

	steps.Define(func(define Definitions) {
		define.Given(`^thing 1 is run$`, func() {
			oneCounter += 1
		}, func() {
			oneCounter -= 1
			Expect(oneCounter).To(Equal(0))
		})

		define.Given(`^thing 2 is run$`, func() {
			twoCounter += 1
		}, func() {
			twoCounter -= 1
			Expect(twoCounter).To(Equal(0))
		})

	})

})

Expects fail with

  Expected
      <int>: -1
  to equal
      <int>: 0

They should pass.

This happens because the after steps are added when the definitions are added, not when the step is encountered in a scenario.