ruby-on-rails - Rspec 让变量产生奇怪的结果
问题描述
我对 RSpec 有一个奇怪的问题,我不太明白。
这是我的port_stock_spec.rb
文件:
# == Schema Information
#
# Table name: port_stocks
#
# id :bigint(8) not null, primary key
# portfolio_id :integer
# stock_id :integer
# volume :integer
# transaction_price :float
# current_price :float
# percent_change :float
# created_at :datetime not null
# updated_at :datetime not null
# current_value :float
# dollar_change :float
# total_spend :float
# transaction_date :datetime
# action :integer
# position :integer default("open")
# ticker :string
# slug :string
#
require 'rails_helper'
RSpec.describe PortStock, type: :model do
let(:stock) { create(:stock, price: 10.00) }
let(:portfolio) { create(:portfolio) }
let(:port_stock_1) { create(:port_stock, stock: stock, portfolio: portfolio, transaction_price: stock.price, action: :buy, volume: 100) }
context "associations" do
it { should belong_to(:portfolio) }
it { should belong_to (:stock) }
end
context "methods" do
it "should accurately calculate the positive percent_change of the current PortStock" do
port_stock_1.current_price = 20.00
expect(port_stock_1.calculate_percent_change).to eql 100.00
end
it "should accurately calculate the negative percent_change of the current PortStock" do
port_stock_1.current_price = 5.00
expect(port_stock_1.calculate_percent_change).to eql(-50.00)
end
it "should accurately calculate the negative dollar_change of the current PortStock" do
port_stock_1.current_price = 5.00
port_stock_1.volume = 1000
expect(port_stock_1.calculate_dollar_change).to eql (-5000.00)
end
# more specs that may or may no interact with the let variables.
it "should accurately calculate the portfolio's initial_dollar_value" do
expect(portfolio.initial_dollar_value).to eql 1000.00
end
结尾
然后我的portfolio.rb
模型上有以下方法:
def calculate_portfolio_initial_dollar_value
if self.portfolio.initial_dollar_value.nil?
self.portfolio.initial_dollar_value = 0.0
end
self.portfolio.initial_dollar_value += (self.transaction_price * self.volume)
self.portfolio.save!
end
当我运行我的测试套件时,最后一个测试一直失败,但它不应该:
Failures:
1) PortStock methods should accurately calculate the portfolio's initial_dollar_value
Failure/Error: expect(portfolio.initial_dollar_value).to eql 1000.00
expected: 1000.0
got: 798229.0
(compared using eql?)
# ./spec/models/port_stock_spec.rb:77:in `block (3 levels) in <top (required)>'
Finished in 5.05 seconds (files took 3.68 seconds to load)
29 examples, 1 failure, 19 pending
所以我把 abinding.pry
放在it
最后几个测试的块中,当我检查portfolio.initial_dollar_value
它时,它会反复更改值。
[1] pry(#<RSpec::ExampleGroups::PortStock::Methods>)> portfolio
=> #<Portfolio:0x00007fcdc5c5db28
id: 14,
user_id: 7,
current_dollar_value: 2864770.0,
percent_change: 75.02,
created_at: Sat, 13 Apr 2019 00:36:24 UTC +00:00,
updated_at: Sat, 13 Apr 2019 00:36:24 UTC +00:00,
num_winners: 2,
num_losers: 7,
initial_dollar_value: 860679.0,
dollar_change: 92865.0>
[2] pry(#<RSpec::ExampleGroups::PortStock::Methods>)> port_stock_1.portfolio
=> #<Portfolio:0x00007fcdc5c5db28
id: 14,
user_id: 7,
current_dollar_value: 150.0,
percent_change: -85.0,
created_at: Sat, 13 Apr 2019 00:36:24 UTC +00:00,
updated_at: Sat, 13 Apr 2019 00:36:42 UTC +00:00,
num_winners: 0,
num_losers: 1,
initial_dollar_value: 1000.0,
dollar_change: -850.0>
[3] pry(#<RSpec::ExampleGroups::PortStock::Methods>)> portfolio
=> #<Portfolio:0x00007fcdc5c5db28
id: 14,
user_id: 7,
current_dollar_value: 150.0,
percent_change: -85.0,
created_at: Sat, 13 Apr 2019 00:36:24 UTC +00:00,
updated_at: Sat, 13 Apr 2019 00:36:42 UTC +00:00,
num_winners: 0,
num_losers: 1,
initial_dollar_value: 1000.0,
dollar_change: -850.0>
[4] pry(#<RSpec::ExampleGroups::PortStock::Methods>)> portfolio
=> #<Portfolio:0x00007fcdc5c5db28
id: 14,
user_id: 7,
current_dollar_value: 150.0,
percent_change: -85.0,
created_at: Sat, 13 Apr 2019 00:36:24 UTC +00:00,
updated_at: Sat, 13 Apr 2019 00:36:42 UTC +00:00,
num_winners: 0,
num_losers: 1,
initial_dollar_value: 1000.0,
dollar_change: -850.0>
[5] pry(#<RSpec::ExampleGroups::PortStock::Methods>)>
我不明白为什么。
想法?
编辑 1
这是portfolio.rb
工厂:
FactoryBot.define do
factory :portfolio do
user
current_dollar_value { Faker::Number.number(7) }
percent_change { Faker::Number.decimal(2) }
num_winners { Faker::Number.number(1) }
num_losers { Faker::Number.number(1) }
initial_dollar_value { Faker::Number.number(6) }
dollar_change { Faker::Number.number(5) }
end
end
编辑 2
我的模型上有一个回调,port_stock.rb
它触发与以下相关的方法portfolio_initial_dollar_value
:
after_save :calculate_portfolio_initial_dollar_value
还有其他影响投资组合其他方面的回调:
after_save :update_portfolio_current_dollar_value
after_save :update_portfolio_initial_dollar_value, if: (:total_spend_previously_changed? || :volume_previously_changed?)
def update_portfolio_current_dollar_value
self.portfolio.current_dollar_value = self.portfolio.port_stocks.open.map(&:current_value).sum
self.portfolio.save!
end
def update_portfolio_initial_dollar_value
self.portfolio.initial_dollar_value = self.portfolio.port_stocks.open.map { |ps| ps.volume * ps.transaction_price }.sum
self.portfolio.save!
end
编辑 3
有关模型 ( port_stock.rb
) 和规范 ( port_stock_spec.rb
) 文件的完整版本,请查看此要点。我不想用那个完整的转储污染 SO。
解决方案
正如@grzekos 指出的那样,您从不打电话stock
或port_stock_1
在执行it "should accurately calculate the portfolio's initial_dollar_value"
测试期间。
为什么?因为您曾经let
设置/创建测试对象。如果您想始终设置/创建,stock
您可以使用(RSpec 文档)或使用这样的块:portfolio
port_stock_1
let!
before
let(:stock) { create(:stock, price: 10.00) }
let(:portfolio) { create(:portfolio) }
let(:port_stock_1) { create(:port_stock, stock: stock, portfolio: portfolio, transaction_price: stock.price, action: :buy, volume: 100) }
before do
stock
portfolio
port_stock_1
end
为什么在调试过程中看到不同的数字pry
?
在您的第一个测试中,您调用了portfolio
使用 FactoryBot 创建的对象。工厂通过 为属性分配了一个随机的 6 位initial_dollar_value
数字Faker::Number.number(6)
。
在您的第二个测试中,您调用了port_stock_1.portfolio
. 现在块let(:port_stock_1)
被评估。这将创建一个PortStock
对象,该对象在其after_save
方法中更新initial_dollar_value
of portfolio
。
的所有子序列调用portfolio
或port_stock_1.portfolio
不再更改的值initial_dollar_value
。