结果校验（validate）
针对 API 响应结果进行预期结果校验
概念
结果校验（又称断言）是测试用例中的重要组成部分，可以对测试用例在运行过程中是否得到了预期结果进行校验，例如对响应状态码进行断言，以及对响应 JSON 中的具体字段进行断言。
目前 HttpRunner 支持两种匹配目标参数的方式，并且内置了丰富的结果检验函数，可以实现满足众多的测试场景需求。
HttpRunner v4.0 结果校验部分的数据结构如下：
type Validator struct {
Check string `json:"check" yaml:"check"`
Assert string `json:"assert" yaml:"assert"`
Expect interface{} `json:"expect" yaml:"expect"`
Message string `json:"msg,omitempty" yaml:"msg,omitempty"`
}
从上面的数据结构可以看出，结果校验内容包含了 4 个字段，分别是字段提取表达式、断言函数、预期结果以及提示信息：
- 字段提取表达式：用于提取目标字段用作断言函数的输入，支持 jmespath 表达式和正则表达式（regex）两种提取方式，填写方式请参考参数提取（extract）章节
- 断言函数：顾名思义，就是用于对目标字段与预期结果是否满足相等、大小、包含、被包含等关系进行断言的函数，目前支持内置函数，不支持自定义拓展
- 预期结果：指定断言的预期结果，用作断言函数的另一个输入
- 提示信息：当前断言操作对应的提示信息，该字段为选填
示例
下面以 YAML 测试用例为例，展示结果校验功能的写法示例：
config:
name: validation demo
teststeps:
- name: get httpbin
request:
method: GET
url: https://www.httpbin.org
validate:
- check: status_code # target field, support both jmespath and regex
assert: eq # assertion method, you can use builtin method or custom defined function
expect: 200 # expected value, supposed to match target field
message: check status code # note message, optional
内置结果校验函数
assert 部分支持填写的内置结果校验函数包括如下内容：
assert | Description | A(check), B(expect) | examples |
|---|---|---|---|
eq, equals, equal | value is equal | A == B | 9 eq 9 |
lt, less_than | less than | A < B | 7 lt 8 |
le, less_or_equals | less than or equals | A <= B | 7 le 8, 8 le 8 |
gt, greater_than | greater than | A > B | 8 gt 7 |
ge, greater_or_equals | greater than or equals | A >= B | 8 ge 7, 8 ge 8 |
ne, not_equal | not equals | A != B | 6 ne 9 |
str_eq, string_equals | string equals | str(A) == str(B) | 123 str_eq ‘123’ |
len_eq, length_equals, length_equal | length equals | len(A) == B | ‘abc’ len_eq 3, [1,2] len_eq 2 |
len_gt, count_gt, length_greater_than | length greater than | len(A) > B | ‘abc’ len_gt 2, [1,2,3] len_gt 2 |
len_ge, count_ge, length_greater_or_equals | length greater than or equals | len(A) >= B | ‘abc’ len_ge 3, [1,2,3] len_gt 3 |
len_lt, count_lt, length_less_than | length less than | len(A) < B | ‘abc’ len_lt 4, [1,2,3] len_lt 4 |
len_le, count_le, length_less_or_equals | length less than or equals | len(A) <= B | ‘abc’ len_le 3, [1,2,3] len_le 3 |
contains | contains | [1, 2] contains 1 | ‘abc’ contains ‘a’, [1,2,3] len_lt 4 |
contained_by | contained by | A in B | ‘a’ contained_by ‘abc’, 1 contained_by [1,2] |
type_match | A and B are in the same type | type(A) == type(B) | 123 type_match 1 |
regex_match | regex matches | re.match(B, A) | ‘abcdef’ regex_match ‘a\w+d’ |
startswith | starts with | A.startswith(B) is True | ‘abc’ startswith ‘ab’ |
endswith | ends with | A.endswith(B) is True | ‘abc’ endswith ‘bc’ |