Question

我目前有：

describe 'least number of moves from x to y' do

  it 'has a populated chessboard' do
    @wp='white-pawn'
    @bp='black-pawn'

    expect(ChessBoard.new.populate_new_board).to eq [
      ['white-castle','white-knight','white-bishop','white-queen','white-king','white-bishop','white-knight','white-castle'],
      [@wp,@wp,@wp,@wp,@wp,@wp,@wp,@wp],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [@bp,@bp,@bp,@bp,@bp,@bp,@bp,@bp],
      ['black-castle','black-knight','black-bishop','black-king','black-queen','black-bishop','black-knight','black-castle']]
  end

工作正常。
我想改变使用let！，所以我尝试了：

describe 'least number of moves from x to y' do

  let!(:wp){'white-pawn'}
  let!(:bp){'black-pawn'}

  it 'has a populated chessboard' do
    expect(ChessBoard.new.populate_new_board).to eq [
      ['white-castle','white-knight','white-bishop','white-queen','white-king','white-bishop','white-knight','white-castle'],
      [@wp,@wp,@wp,@wp,@wp,@wp,@wp,@wp],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [@bp,@bp,@bp,@bp,@bp,@bp,@bp,@bp],
      ['black-castle','black-knight','black-bishop','black-king','black-queen','black-bishop','black-knight','black-castle']]
  end

但它失败了，因为我现在对所有的@bp和@wp值都是零。

如何修复，即为期望值编写let语法正确？

Answer 1

let!正在设置本地方法，而不是实例变量，所以这有效：

 it 'has a populated chessboard' do
    expect(ChessBoard.new.populate_new_board).to eq [
      ['white-castle','white-knight','white-bishop','white-queen','white-king','white-bishop','white-knight','white-castle'],
      [wp,wp,wp,wp,wp,wp,wp,wp],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [bp,bp,bp,bp,bp,bp,bp,bp],
      ['black-castle','black-knight','black-bishop','black-king','black-queen','black-bishop','black-knight','black-castle']]
  end

Answer 2

您需要使用wp代替@wp和bp而不是@bp，因为这些是方法，而不是实例变量：

describe 'least number of moves from x to y' do

  let!(:wp){'white-pawn'}
  let!(:bp){'black-pawn'}

  it 'has a populated chessboard' do

    expect(ChessBoard.new.populate_new_board).to eq [
      ['white-castle','white-knight','white-bishop','white-queen','white-king','white-bishop','white-knight','white-castle'],
      [wp,wp,wp,wp,wp,wp,wp,wp],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [nil,nil,nil,nil,nil,nil,nil,nil],
      [bp,bp,bp,bp,bp,bp,bp,bp],
      ['black-castle','black-knight','black-bishop','black-king','black-queen','black-bishop','black-knight','black-castle']]
  end
end

rspec - 如何使用让！设置2个变量？

2 个答案: