RSpec stub_request如何返回数组格式响应体解决each方法报错

编写Rspec服务单元测试时触发报错：undefined method 'each' for "invoices":String

• 报错触发逻辑：业务方法需要遍历解析接口响应中的invoices数组，但当前stub返回的响应中invoices被识别为字符串类型，无法执行each遍历。

被测业务方法 #

def generate_invoices
  invoices_ids = []
  response = HTTParty.get('https://books.zoho.com/api/v3/invoices?organization_id='\
    "#{ENV['ZOHO_ORGANISATION_ID']}&cf_lc_contract_id_startswith=#{@contract_id}&"\
    'cf_facture_final=true', headers: { 'Authorization' => "Zoho-oauthtoken #{@access_token}" })

  response.code == 200 ? response : raise_error(response.body)

  response['invoices'].each do |invoice|
    invoices_ids.push invoice['invoice_id']
  end

  invoices_ids.join(',')
end

现有stub模拟配置 #

stub_request(:get, 'https://books.zoho.com/api/v3/invoices?cf_facture_final=true'\
          "&cf_lc_contract_id_startswith=123&organization_id=#{ENV['ZOHO_ORGANISATION_ID']}")
          .with(headers: { 'Authorization' => 'Zoho-oauthtoken access_token' })
          .to_return(status: 200, body: { 'invoices' => [{ "invoice_id": '123' }] }.to_json,
                     headers: {})

stub返回响应时没有设置Content-Type: application/json响应头，HTTParty不会自动将JSON格式的响应体字符串解析为Ruby Hash结构。此时调用response['invoices']实际是在JSON字符串上按字符索引取值，拿到的是字符串"invoices"，字符串类型没有数组遍历的each方法，因此触发报错。

在stub的返回头中补充正确的JSON内容类型标识，和真实Zoho接口的响应头保持一致，让HTTParty自动完成响应体解析：

stub_request(:get, 'https://books.zoho.com/api/v3/invoices?cf_facture_final=true'\
          "&cf_lc_contract_id_startswith=123&organization_id=#{ENV['ZOHO_ORGANISATION_ID']}")
          .with(headers: { 'Authorization' => 'Zoho-oauthtoken access_token' })
          .to_return(
            status: 200,
            body: { 'invoices' => [{ "invoice_id": '123' }] }.to_json,
            headers: { 'Content-Type' => 'application/json' }
          )

调整后重新运行测试，HTTParty会自动把响应体解析为Hash结构，response['invoices']可以正常拿到数组类型数据，遍历逻辑可正常执行。

内容的提问来源于stack exchange，提问作者Wako