爱上ruby on rails三：rspec 单元测试

1. gemfile添加：

group :development, :test do
  gem 'rspec-rails', '~> 5.0.0'
end

2. bundle install
3. bin/rails generate rspec:install
4. bin/rails generate rspec:model user：生成spec/models/user_spec.rb；或者rails g rspec:request items生成请求测试文件

require 'rails_helper'  // 相当于import外面的一些帮助方法

RSpec.describe User, type: :model do
  it "有email" do
    user = User.new email: "xiaowu@qq.com"
    expect(user.email).to eq "xiaowu@qq.com"
  end
end

5. 配置测试环境数据库： database.yml配置：

test:
  <<: *default
  database: mangosteen_test
  username: mangosteen 
  password: 123456 
  host: db-for-mangosteen

6. 创建数据库：RAILS_ENV=test bin/rails db:create
7. 创建表：RAILS_ENV=test bin/rails db:migrate
8. bundle exec rspec

测试请求(Rspec每次请求完会自动清空数据表)

1. bin/rails g rspec:request items 生成对应的items_spec.rb
2. 代码示例：

require "rails_helper"

RSpec.describe "Items", type: :request do
  describe "index by page" do
    it "works! (now write some real specs)" do
      11.times { Item.create amount: 100 }
      expect(Item.count).to eq(11)
      get "/api/v1/items"
      expect(response).to have_http_status(200)
      json = JSON.parse(response.body)
      expect(json["resources"].size).to eq(10)
      get "/api/v1/items?page=2&per_page=5"
      expect(response).to have_http_status(200)
      json = JSON.parse(response.body)
      expect(json["resources"].size).to eq(5)
    end
  end
  describe "create" do
    it "can create an item" do
      expect {
        post "/api/v1/items", params: { amount: 99 }
      }.to change { Item.count }.by(+1)
      expect(response).to have_http_status 200
      json = JSON.parse response.body
      expect(json["resource"]["id"]).to be_an(Numeric)
      expect(json["resource"]["amount"]).to eq 99
    end
  end
end

3. bundle exec rspec