来自csv.read模拟文件的rspec测试结果

Question

我正在使用ruby 1.9而我正在尝试做BDD.我的第一个测试"应该在csv中读取",但是第二个我需要模拟文件对象的测试却没有.

这是我的型号规格:

require 'spec_helper'

describe Person do
  describe "Importing data" do
    let(:person) { Person.new }

    let(:data) { "title\tsurname\tfirstname\t\rtitle2\tsurname2\tfirstname2\t\r"}
    let(:result) {[["title","surname","firstname"],["title2","surname2","firstname2"]] }

    it "should read in the csv" do
      CSV.should_receive(:read).
        with("filename", :row_sep => "\r", :col_sep => "\t")
      person.import("filename")
    end

    it "should have result" do
      filename = mock(File, :exists? => true, :read => data)
      person.import(filename).should eq(result)
    end
  end
end

这是迄今为止的代码:

class Person < ActiveRecord::Base
  attr_accessor :import_file

  def import(filename)
    CSV.read(filename, :row_sep => "\r", :col_sep => "\t")
  end
end

我基本上想要模拟一个文件,以便当CSV方法尝试从文件中读取时它返回我的数据变量.然后我可以测试它是否等于我的结果变量.

Answer 1

你可以存根File.open:

let(:data) { "title\tsurname\tfirstname\rtitle2\tsurname2\tfirstname2\r" }
let(:result) {[["title","surname","firstname"],["title2","surname2","firstname2"]] }

it "should parse file contents and return a result" do
  expect(File).to receive(:open).with("filename","rb") { StringIO.new(data) }
  person.import("filename").should eq(result)
end

StringIO 基本上包装一个字符串,使其行为像IO对象(在这种情况下为文件)