如何使 Rspec 测试变为绿色？

Question

我在下面有一段代码作为参数，它从 CSV 文件中的一行中获取信息并创建一个 Employee 对象。我是 Rspec 的新手，即使我知道我的解决方案按我想要的方式运行，我似乎也无法通过测试。在我努力学习测试驱动开发的过程中，我想更好地了解 Rspec。我怎样才能编写一个测试来证明这段代码有效？我意识到这个过程应该反过来（在创建最终产品之前先测试），但我这样做是为了尝试了解规范如何更好地工作。如果您需要更多我的代码，请告诉我：

CSV 文件：

first_name,last_name,annual_income,tax_paid,tax_rate
Johnny,Smith,120000,28000,38
Jane,Doe,140000,30000,40
Liz,Lemon,,21000,30
,Orsillio,40000,8800,18
Eric,Schmidt,54000,,28

员工类：

class Employee
  attr_reader :last_name, :first_name, :annual_income, :tax_paid, :tax_rate

  def initialize(attributes) **#<-where the csv row is being passed in but in another main file used to run the code**

    @last_name = attributes['last_name'] ||="[Last Name]"
    @first_name = attributes['first_name'] ||="[First Name]"
    @annual_income = attributes['annual_income'].to_f ||= 0
    @tax_paid = attributes['tax_paid'].to_f ||= 0
    @tax_rate = attributes['tax_rate'].to_f ||= 0
  end
end

几个 Rspec 测试尝试之一：

require 'rspec'
require_relative 'employee'

  describe Employee do
    it 'instantiated Employee class object should instantiate when missing arguments are passed in' do
      expect(Employee.new("").first_name).to eql("[First Name]")
    end
  end

这是测试的结果：

F

Failures:

  1) Employee instantiated Employee class object should instantiate when missing arguments are passed in
     Failure/Error: expect(Employee.new("").first_name).to eql("[First Name]")
     IndexError:
       string not matched
     # ./employee.rb:9:in `[]='
     # ./employee.rb:9:in `initialize'
     # ./employee_spec.rb:6:in `new'
     # ./employee_spec.rb:6:in `block (2 levels) in <top (required)>'

Finished in 0.00029 seconds
1 example, 1 failure

Failed examples:

rspec ./employee_spec.rb:5 # Employee instantiated Em

Answer 1

这不是您的测试错误，而是您的测试很好地完成了它的工作，并告诉您您的代码有问题。

你有

@last_name = attributes['last_name'] ||="[Last Name]"

也许您应该在尝试分配之前检查属性参数是否包含您正在寻找的值？所有属性都一样

该错误很可能是因为您将字符串作为参数而不是散列传递，但是当您调用 Employee.new("") 时，您试图访问该字符串，就好像它是散列一样

所以把你的初始化方法改成这个

  def initialize(attributes) #**#<-where the csv row is being passed in but in another main file used to run the code**
    if attributes.is_a? Hash
        @last_name = attributes['last_name'] ||="[Last Name]"
        @first_name = attributes['first_name'] ||="[First Name]"
        @annual_income = attributes['annual_income'].to_f ||= 0
        @tax_paid = attributes['tax_paid'].to_f ||= 0
        @tax_rate = attributes['tax_rate'].to_f ||= 0
    else
        @last_name = "[Last Name]"
        @first_name = "[First Name]"
        @annual_income = 0
        @tax_paid =  0
        @tax_rate =  0
    end
  end

您的测试将通过，您的课程已确定。

测试摇滚！ :)