如何使用RSpec指定#initialize行为？例如：
generator.rb
@H_404_4@class Generator attr_accessor :seed def initialize(seed = nil) @seed = seed || pick_seed end def pick_seed Time.now.to_i end endgenerator_spec.rb
@H_404_4@require 'generator' describe Generator it "calls 'pick_seed' method unless seed specified" do end end解决方法
对我来说,期望是在协作者之间设计对话.所以,你必须决定 – #pick_seed是内部实现细节还是协作角色界面的一部分？
如果pick_seed是一个实现细节,期望是工作的错误工具.而且,因为你有一个种子的访问器,你可以这样进行(注意一个例子)
@H_404_4@class Generator attr_accessor :seed def initialize(seed = nil) @seed = seed || pick_seed end def pick_seed Time.now.to_i end end describe Generator do context "creating" do context "when a seed is specified" do it "uses that seed" do seed = 123 generator = Generator.new(seed) generator.seed.should == seed end end context "when a seed is not specified" do it "creates its own seed" do generator = Generator.new generator.seed.should_not be_nil end end end endOTOH,如果选择种子是“种子选择器”角色的一部分,那么嘲讽在设计种子选择器时是有价值的,依赖注入是分配角色的标准方法.你可以写下如下：
@H_404_4@class GeneratorWithCollaborator attr_accessor :seed def initialize(seed = nil,seed_picker = self) @seed = seed || seed_picker.pick_seed end def pick_seed Time.now.to_i end end describe GeneratorWithCollaborator do context "creating" do context "when a seed is specified" do it "uses that seed" do seed = 123 seed_picker = double('seed picker') seed_picker.should_not_receive(:pick_seed) generator = GeneratorWithCollaborator.new(seed,seed_picker) generator.pick_seed end end context "when a seed is not specified" do it "delegates to its seed picker" do seed_picker = double('seed picker') seed_picker.should_receive(:pick_seed) generator = GeneratorWithCollaborator.new(nil,seed_picker) end end end end