Postman之JSON Schema 校验（验证响应结构）

一、使用TV4进行JSON模式验证

在测试中除了断言响应值的是否相等，还需要断言响应数据的结构及字段属性是否发生了变化，如果响应数据的结构及字段属性发现了变化，就需要对应的调整客户端的代码，因此，需要对 JSON 的 Schema 进行校验。比如说，要检验HttpBin请求的头信息结构及字段属性是否正确，代码如下。

首先，将响应结果复制，并粘贴至https://www.jsonschema.net/将内容转为json schema语言。

然后，将转换后的Json schema复制并粘贴至script当中。

var schema = {
  "definitions": {},
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "http://example.com/root.json",
  "type": "object",
  "title": "The Root Schema",
  "required": [
    "args",
    "headers",
    "origin",
    "url"
  ],
  "properties": {
    "args": {
      "$id": "#/properties/args",
      "type": "object",
      "title": "The Args Schema"
    },
    "headers": {
      "$id": "#/properties/headers",
      "type": "object",
      "title": "The Headers Schema",
      "required": [
        "Accept",
        "Accept-Encoding",
        "Cache-Control",
        "Host",
        "Postman-Token",
        "User-Agent",
        "X-Amzn-Trace-Id"
      ],
      "properties": {
        "Accept": {
          "$id": "#/properties/headers/properties/Accept",
          "type": "string",
          "title": "The Accept Schema",
          "default": "",
          "examples": [
            "*/*"
          ],
          "pattern": "^(.*)$"
        },
        "Accept-Encoding": {
          "$id": "#/properties/headers/properties/Accept-Encoding",
          "type": "string",
          "title": "The Accept-encoding Schema",
          "default": "",
          "examples": [
            "gzip, deflate, br"
          ],
          "pattern": "^(.*)$"
        },
        "Cache-Control": {
          "$id": "#/properties/headers/properties/Cache-Control",
          "type": "string",
          "title": "The Cache-control Schema",
          "default": "",
          "examples": [
            "no-cache"
          ],
          "pattern": "^(.*)$"
        },
        "Host": {
          "$id": "#/properties/headers/properties/Host",
          "type": "string",
          "title": "The Host Schema",
          "default": "",
          "examples": [
            "www.httpbin.org"
          ],
          "pattern": "^(.*)$"
        },
        "Postman-Token": {
          "$id": "#/properties/headers/properties/Postman-Token",
          "type": "string",
          "title": "The Postman-token Schema",
          "default": "",
          "examples": [
            "1ac1b5ae-5f8f-478b-8d6c-c955c7d7fb25"
          ],
          "pattern": "^(.*)$"
        },
        "User-Agent": {
          "$id": "#/properties/headers/properties/User-Agent",
          "type": "string",
          "title": "The User-agent Schema",
          "default": "",
          "examples": [
            "PostmanRuntime/7.22.0"
          ],
          "pattern": "^(.*)$"
        },
        "X-Amzn-Trace-Id": {
          "$id": "#/properties/headers/properties/X-Amzn-Trace-Id",
          "type": "string",
          "title": "The X-amzn-trace-id Schema",
          "default": "",
          "examples": [
            "Root=1-5e5b5ee9-c787ddce57b2f6a67c39506e"
          ],
          "pattern": "^(.*)$"
        }
      }
    },
    "origin": {
      "$id": "#/properties/origin",
      "type": "string",
      "title": "The Origin Schema",
      "default": "",
      "examples": [
        "61.157.7.177"
      ],
      "pattern": "^(.*)$"
    },
    "url": {
      "$id": "#/properties/url",
      "type": "string",
      "title": "The Url Schema",
      "default": "",
      "examples": [
        "http://www.httpbin.org/get"
      ],
      "pattern": "^(.*)$"
    }
  }
}




pm.test('Schema is valid', function() {
  var jsonData = pm.response.json();
  pm.expect(tv4.validate(jsonData, schema)).to.be.true;
});

这样，只要字段出现了类型的变化或者缺失，测试马上就知道了。

二、使用AJV进行JSON模式验证

使用方法和使用TV4进行JSON模式验证一样。

var Ajv = require('ajv'),
 ajv = new Ajv({logger: console}),
 schema = {
     "properties": {
         "alpha": {
             "type": "boolean"
         }
     }
 };

pm.test('Schema is valid', function() {
 pm.expect(ajv.validate(schema, {alpha: true})).to.be.true;
 pm.expect(ajv.validate(schema, {alpha: 123})).to.be.false;
});