Karate :有没有办法从示例变量中获取 JSON 对象键的长度？

Question

我通过了 Karate 考试:

  Scenario Outline: Find all the the prime factors in the range from <start> to <end> are <result>
    Given path '/primefactors'
    And param start = <start>
    And param end = <end>
    When method get
    Then status 200
    And match header content-type contains 'application/json'
    And match header content-type contains 'charset=utf-8'
    And match response == {numbers:<result>, start:<start>, end:<end>, count:<count>, type:PrimeFactors}
    Examples:
      | start | end | result                                       | count
      | 8     | 10  | {8: [2,2,2], 9:[3,3], 10:[2,5]}              | 3
      | 13    | 16  | {13: [13], 14:[2,7], 15:[3,5], 16:[2,2,2,2]} | 4

但是，我想做的是没有示例中的计数变量:部分，只是通过这种方式从结果对象变量中的键数的长度导出计数:

 Scenario Outline: Find all the the prime factors in the range from <start> to <end> are <result>
    Given path '/primefactors'
    And param start = <start>
    And param end = <end>
    When method get
    Then status 200
    And match header content-type contains 'application/json'
    And match header content-type contains 'charset=utf-8'
    And def result = <result>
    And match response == {numbers:<result>, start:<start>, end:<end>, count:'#(Object.keys(result).length)', type:PrimeFactors}
    Examples:
      | start | end | result                                        
      | 8     | 10  | {8: [2,2,2], 9:[3,3], 10:[2,5]}               
      | 13    | 16  | {13: [13], 14:[2,7], 15:[3,5], 16:[2,2,2,2]}  

当我尝试这个时，我得到一个错误:

primefactors.feature:33 - javascript evaluation failed: Object.keys(result).length, TypeError: {8=[2,2,2], 9=[3,3], 10=[2,5]} is not an Object in <eval> at line number 1

测试失败。

鉴于 Object.keys(result).length 是有效的 JS(使用 Chrome 开发控制台):

result = {8: [2,2,2], 9:[3,3], 10:[2,5]} 
{8: Array(3), 9: Array(2), 10: Array(2)}
Object.keys(result).length
3

我做错了什么？执行此操作的正确方法是什么？

更新(2019 年 4 月 9 日) 以下工作成功:

  Background:
    * url baseUrl
    * configure lowerCaseResponseHeaders = true
    * def keys = function(o){ return o.keySet() }
    * def values = function(o){ return o.values() }
    * def size = function(o){ return o.size() }

  Scenario Outline: Find all the the prime factors in the range from <start> to <end> are <result>
    Given path '/primefactors'
    And param start = <start>
    And param end = <end>
    When method get
    Then status 200
    And match header content-type contains 'application/json'
    And match header content-type contains 'charset=utf-8'
    And def result = <result>
    And match response == {numbers:<result>, start:<start>, end:<end>, count: '#(size(result))', type:PrimeFactors}
    Examples:
      | start | end | result
      | 8     | 10  | {8: [2,2,2], 9:[3,3], 10:[2,5]}
      | 13    | 16  | {13: [13], 14:[2,7], 15:[3,5], 16:[2,2,2,2]}

Answer 1

是的， Karate 中的 JS 并不是你在野外看到的真正的 JS，当我们移动到 Graal 时这可能会改变

同时请使用这个技巧从 JSON 中获取键、大小(和值):

Scenario: json behaves like a java map within functions
  * def payload = { a: 1, b: 2 }
  * def keys = function(o){ return o.keySet() }
  * def values = function(o){ return o.values() }
  * def size = function(o){ return o.size() }
  * json result = keys(payload)
  * match result == ['a', 'b']
  * json result = values(payload)
  * match result == [1, 2]
  * def length = size(payload)
  * match length == 2

您应该能够在嵌入式表达式中使用函数，例如:'#(keys(foo))'

在未来，我们计划添加一个 karate.keysOf() 和 karate.sizeOf() API 来使这更容易。