如何为模型范围方法创建规范？

Question

我在评估模型中有scope方法，我在AssessmentsController中对评估集合调用了这个方法，但是我不能为这个方法创建测试，因为: 1)响应时我没有得到risk_value，但是在控制器(@assessments.with_assessment_progresses(@customer_id))中我得到了以下内容：

[
  {
    "id": 4,
    "name": "Assessment_1",
    "created_at": "2020-04-01T17:29:50.528Z",
    "updated_at": "2020-04-01T17:29:50.528Z",
    "risk_value": "3.92156862745098"
  },
  ...
]

2)我不明白如何从结果中删除created_at和updated_at。

app/models/assessment.rb

scope :with_assessment_progresses, ->(customer_id) {
  joins(Arel.sql("LEFT JOIN assessment_progresses ON (assessment_progresses.assessment_id = assessments.id AND assessment_progresses.customer_id = #{customer_id})")).
  select("assessments.*, assessment_progresses.risk_value")
}

spec/models/assessment_spec.rb

describe "Method 'with_assessment_progresses'" do
  let!(:admin)                     { create(:admin) }
    let!(:customer)                { create(:customer, created_by: admin.id) }
  let!(:assessment)                { create(:assessment) }
    let!(:assessment_progress_1)   { create(:assessment_progress, customer_id: customer.id, assessment_id: assessment.id, risk_value: 3.812) }

  it "return assessments with risk_value for customer" do
    assessment_with_risk = Assessment.with_assessment_progresses(customer.id)

    assessment_with_risk.delete("created_at")
    assessment_with_risk.delete("updated_at")

    expect(assessment_with_risk.length).to eq(1)
    expect(assessment_with_risk).to eq(
      [
        {
          "id"=> assessment.id,
          "name"=> assessment.name,
          "risk_value"=> assessment_progress_1.risk_value
        }
      ]
    )

  end
end

Answer 1

你用

.select("assessments.*, assessment_progresses.risk_value")

created_at和updatet_at来自于assessements.*，这些列自动为活动记录模型生成。如果您只想要某些值，则只选择

.select("assessments.id, assessments.name ,assessment_progresses.risk_value")

Answer 2

我解决了这个问题：

Assessment.with_assessment_progresses(customer.id).as_json

我用以下方式删除时间戳：

object.each{ |h| h.delete("updated_at") && h.delete("created_at")}