Rails控制器测试：如何验证指定服务类被正确调用且传入参数正确？

以下是基于Rails生态常用的RSpec框架的测试代码，核心逻辑是对EsignGenieSendByTemplate的初始化方法做参数断言，同时mock服务的process方法避免触发真实第三方请求：

require "rails_helper"

# 替换为你实际的控制器类名
RSpec.describe SignaturesController, type: :controller do
  # 提前准备测试依赖数据
  let(:test_client) { Client.create!(name: "测试客户", 补充你的Client模型所有必填字段) }
  let(:test_external_docs) do
    [
      ExternalDocument.create!(name: "合同1", 补充ExternalDocument模型必填字段),
      ExternalDocument.create!(name: "附件1", 补充ExternalDocument模型必填字段)
    ]
  end
  let(:test_form_values) { { signer_name: "张三", expire_date: "2024-12-31" } }

  describe "POST #send_for_signature" do
    it "使用正确参数初始化EsignGenieSendByTemplate服务" do
      # 配置服务初始化的参数断言
      expect(EsignGenieSendByTemplate).to receive(:new).with(
        client: test_client,
        external_documents: test_external_docs,
        form_values: test_form_values.with_indifferent_access
      ).and_return(double(process: { "result" => "success" }))

      # 发起控制器请求
      post :send_for_signature, params: {
        client_id: test_client.id,
        document_ids: test_external_docs.map(&:id),
        form_values: test_form_values
      }

      # 验证响应符合预期
      expect(response).to have_http_status(:ok)
    end

    # 可选补充服务调用失败的场景测试
    it "服务返回失败时响应对应错误信息" do
      error_desc = "签名方手机号缺失"
      allow(EsignGenieSendByTemplate).to receive(:new).and_return(
        double(process: { "result" => "fail", "error_description" => error_desc })
      )

      post :send_for_signature, params: {
        client_id: test_client.id,
        document_ids: test_external_docs.map(&:id),
        form_values: test_form_values
      }

      expect(response).to have_http_status(:unprocessable_entity)
      expect(JSON.parse(response.body)).to eq(error_desc)
    end
  end
end

注意事项 #

• 如果使用Rails自带的Minitest框架，逻辑完全一致，只需要把RSpec的接收断言替换为Minitest对应的mock断言即可
• 测试中form_values参数后加with_indifferent_access是因为控制器拿到的params默认是支持符号/字符串键混用的HashWithIndifferentAccess类型，加上该匹配可以避免参数类型不匹配导致的断言误判

内容的提问来源于stack exchange，提问作者Jeremy Thomas