courses#destroy 刪除資料

編輯 spec/controllers/courses_controller_spec.rb，加入另一段 Test。

describe "DELETE destroy" do
  it "assigns @course" do
    course = create(:course)

    delete :destroy, id: course.id

    expect(assigns[:course]).to eq(course)
  end

  it "deletes a record" do
    course = create(:course)

    expect { delete :destroy, id: course.id }.to change { Course.count }.by(-1)
  end

  it "redirects to courses_path" do
    course = create(:course)

    delete :destroy, id: course.id

    expect(response).to redirect_to courses_path
  end
end

$ rspec spec/controllers/courses_controller_spec.rb
.................FFF

Failures:

  1) CoursesController DELETE destroy assigns @course
     Failure/Error: delete :destroy, params: { id: course.id }

     AbstractController::ActionNotFound:
       The action 'destroy' could not be found for CoursesController

  2) CoursesController DELETE destroy deletes a record
     Failure/Error: expect { delete :destroy, params: { id: course.id } }.to change { Course.count }.by(-1)

     AbstractController::ActionNotFound:
       The action 'destroy' could not be found for CoursesController

  3) CoursesController DELETE destroy redirects to courses_path
     Failure/Error: delete :destroy, params: { id: course.id }

     AbstractController::ActionNotFound:
       The action 'destroy' could not be found for CoursesController

Finished in 0.18993 seconds (files took 1.23 seconds to load)
20 examples, 3 failures

Failed examples:

rspec ./spec/controllers/courses_controller_spec.rb:160 # CoursesController DELETE destroy assigns @course
rspec ./spec/controllers/courses_controller_spec.rb:168 # CoursesController DELETE destroy deletes a record
rspec ./spec/controllers/courses_controller_spec.rb:174 # CoursesController DELETE destroy redirects to courses_path

補上 action

在 app/controllers/courses_controller.rb 加入 destroy 這個 action：

def destroy
  @course = Course.find(params[:id])
  @course.destroy

  redirect_to courses_path
end