Rspec没有找到类方法

Question

我正在为我的后端作业编写一些测试，我遇到了一个奇怪的问题，rspec没有找到我的方法。

我写了一个简单的类&测试来说明这个问题：

应用程序/相互作用蛋白/ tmp_test.rb：

class TmpTest 
    def call 
    a = 10 
    b = 5 
    b.substract_two 
    return a + b 
    end 

    def substract_two 
    c = self - 2 
    return c 
    end 
end 

规格/相互作用蛋白/ tmp_test.rb：

require 'rails_helper' 

describe TmpTest do 
    context 'when doing the substraction' do 
    it 'return the correct number' do 
     expect(described_class.call).to eq(13) 
    end 
    end 
end 

输出：

TmpTest 
    when doing the substraction 
    return the correct number (FAILED - 1) 

Failures: 

    1) TmpTest when doing the substraction return the correct number 
    Failure/Error: expect(described_class.call).to eq(13) 

    NoMethodError: 
     undefined method `call' for TmpTest:Class 
    # ./spec/interactors/tmp_test.rb:6:in `block (3 levels) in <top (required)>' 

Finished in 0.00177 seconds (files took 1.93 seconds to load) 
1 example, 1 failure 

Failed examples: 

rspec ./spec/interactors/tmp_test.rb:5 # TmpTest when doing the substraction return the correct number 

Answer 1

这不是一个类方法，它是一个实例方法。你的测试应该是这样的：

describe TmpTest do 
    subject(:instance) { described_class.new } 

    context 'when doing the subtraction' do 
    it 'returns the correct number' do 
     expect(instance.call).to eq(13) 
    end 
    end 
end 

Answer 2

这是一个完整的混乱。修正版本注释：

class TmpTest 
    def call 
    a = 10 
    b = 5 
    # b.substract_two # why do you call method of this class on b?! 
    a + subtract_two(b) 
    end 

    def substract_two(from) 
    from - 2 
    end 
end 

另外：不要在方法的最后一行用return。