RSpec中hash_including匹配不符合预期问题排查

嘿，我帮你找到了测试断言失败的核心原因，咱们一步步来看：

问题回顾 #

API返回的JSON响应 #

{ 
  "data": { "someFunction": null }, 
  "errors": [ 
    { 
      "message": "Email was already confirmed, please try signing in", 
      "locations": [ { "line": 9, "column": 2 } ], 
      "path": [ "someFunction" ], 
      "extensions": { "code": "USER_ERROR" } 
    } 
  ] 
}

你编写的测试断言 #

expect(json_response[:errors]).to contain_exactly( 
  hash_including( 
    message: "Email was already confirmed, please try signing in.", 
    extensions: { code: 'USER_ERROR' } 
  ) 
)

测试失败提示 #

expected collection contained: [hash_including(:message=>"Email was already confirmed, please try signing in.", :extensions=>{:code=>"USER_ERROR"})]
actual collection contained: [{:extensions=>{:code=>"USER_ERROR"}, :locations=>[{:column=>9, :line=>2}], :message=>"Email was already confirmed, please try signing in", :path=>["someFunction"]}]
the missing elements were: [hash_including(:message=>"Email was already confirmed, please try signing in.", :extensions=>{:code=>"USER_ERROR"})]
the extra elements were: [{:extensions=>{:code=>"USER_ERROR"}, :locations=>[{:column=>9, :line=>2}], :message=>"Email was already confirmed, please try signing in", :path=>["someFunction"]}]

错误根源 #

你仔细对比断言里的message和实际响应的message，会发现只差了一个末尾的句号！

• 断言中的message："Email was already confirmed, please try signing in."（最后有个.）
• 实际响应的message："Email was already confirmed, please try signing in"（最后没有.）

字符串匹配是完全精确的，哪怕只差一个标点符号都会导致hash_including判断不匹配，进而让整个断言失败。

修复方案 #

只需要把断言里message末尾的句号去掉，和实际响应保持一致即可：

expect(json_response[:errors]).to contain_exactly( 
  hash_including( 
    message: "Email was already confirmed, please try signing in", 
    extensions: { code: 'USER_ERROR' } 
  ) 
)

另外补充个小技巧：因为你的错误数组里只有一个元素，也可以用include来简化断言，效果完全相同，写法更简洁：

expect(json_response[:errors]).to include( 
  hash_including( 
    message: "Email was already confirmed, please try signing in", 
    extensions: { code: 'USER_ERROR' } 
  ) 
)

内容的提问来源于stack exchange，提问作者aarona