"RSpec 测试破坏动作"

Question

I'm trying to test the 'destroy' action for my nested comments controller.

  def create
    @comment = @movie.comments.new(comment_params.merge(user: current_user))

    if @comment.save
      flash[:notice] = 'Comment successfully added'
      redirect_to @movie
    else
      flash.now[:alert] = 'You can only have one comment per movie'
      render 'movies/show'
    end
  end

  def destroy
    @comment = @movie.comments.find(params[:id])

    if @comment.destroy
      flash[:notice] = 'Comment successfully deleted'
    else
      flash[:alert] = 'You are not the author of this comment'
    end
    redirect_to @movie
  end

  private

  def comment_params
    params.require(:comment).permit(:body)
  end
  def set_movie
    @movie = Movie.find(params[:movie_id])
  end

Answer 1

You need to specify id of a comment you want to remove:

it "deletes comment" do
  comment = FactoryBot.create(:comment, movie: movie, user: user)

  expect do
    delete :destroy, params { id: comment.id, movie_id: movie.id }
  end.to change(Comment, :count).by(-1)
  # ...
end

Answer 2

I want to contribute here with one more approach. Sometimes you have to be sure that you've deleted the exact instance (comment_1, not comment_2).

it "deletes comment" do
  comment_1 = FactoryBot.create(:comment, movie: movie, user: user)
  comment_2 = FactoryBot.create(:comment, movie: movie, user: user)

  delete :destroy, params { id: comment_1.id, movie_id: movie.id }

  expect { comment_1.reload }.to raise_error(ActiveRecord::RecordNotFound)
  # ...
end

Answer 3

Somehow I was never able to pass an ID, either in params {} or as a direct argument following "delete". Instead, I made it work like so:

it "DELETE will cause an exception" do
  delete "/comments/#{comment.id}"
  expect { comment.reload }.to raise_error(ActiveRecord::RecordNotFound)
end