如何在Postman中实现JSON Schema的严格校验？

我在Postman中进行JSON Schema校验，代码如下：

schema = {
    "items": {
        "required": [
            "id",
            "payment_id",
            "bank_info_id",
            "account_number",
            "account_owner",
            "entity_sub_systems",
            "is_main",
            "public_id"
        ]
    }
}

pm.test("JSON schema check", function () {
    pm.response.to.have.jsonSchema(schema);
});

该校验可检测必填键缺失或键名错误（如响应中用"isMain"替代"is_main"时会失败），但无法检测响应JSON中存在Schema未定义的额外键。例如：

schema = {
    "items": {
        "required": [
            "id",
            "payment_id",
            "bank_info_id",
            "is_main",
            "public_id"
        ]
    }
}

响应体：

{
    "id":"65161",
    "payment_id":"65161",
    "bank_info_id":"65161",
    "is_main":true,
    "public_id":"65161",
    "something":"65161"
}

此时校验不会失败。我尝试了Postman文档提到的Tiny validator（tv4），但Postman 10版本后不再支持，且该方法同样无法检测额外键：

var jsonData = JSON.parse(responseBody);

pm.test('Checking Response Against Schema Validation', function() {
    var result=tv4.validateMultiple(jsonData, schema);
    console.log(result);
    pm.expect(result.valid).to.be.true;
});

请问如何实现响应JSON严格遵循指定JSON Schema键的校验？

要实现严格校验，禁止响应中出现Schema未定义的额外键，只需在JSON Schema中添加additionalProperties: false配置，同时建议明确指定每个字段的类型，让校验逻辑更严谨。

1. 针对数组类型的响应（对应代码中的items结构） #

如果响应是数组，每个数组元素为对象，需在items内部配置additionalProperties: false，可补充字段类型定义：

schema = {
    "type": "array",
    "items": {
        "type": "object",
        "required": [
            "id",
            "payment_id",
            "bank_info_id",
            "account_number",
            "account_owner",
            "entity_sub_systems",
            "is_main",
            "public_id"
        ],
        "additionalProperties": false, // 禁止额外字段
        "properties": { // 明确字段类型，增强校验精度
            "id": {"type": "string"},
            "payment_id": {"type": "string"},
            "bank_info_id": {"type": "string"},
            "account_number": {"type": "string"},
            "account_owner": {"type": "string"},
            "entity_sub_systems": {"type": "array"}, // 根据实际业务类型调整
            "is_main": {"type": "boolean"},
            "public_id": {"type": "string"}
        }
    }
}

pm.test("JSON schema check (strict mode)", function () {
    pm.response.to.have.jsonSchema(schema);
});

2. 针对单个对象类型的响应 #

如果响应是单个对象（而非数组），直接在对象层级添加additionalProperties: false：

schema = {
    "type": "object",
    "required": [
        "id",
        "payment_id",
        "bank_info_id",
        "is_main",
        "public_id"
    ],
    "additionalProperties": false,
    "properties": {
        "id": {"type": "string"},
        "payment_id": {"type": "string"},
        "bank_info_id": {"type": "string"},
        "is_main": {"type": "boolean"},
        "public_id": {"type": "string"}
    }
}

pm.test("JSON schema check (strict mode)", function () {
    pm.response.to.have.jsonSchema(schema);
});

原理说明 #

• additionalProperties: false是JSON Schema的标准关键字，用于限制对象只能包含Schema中properties定义的字段，或required列表中指定的字段（未定义properties时）。
• Postman内置的JSON Schema校验器完全支持该关键字，无需依赖第三方工具，适配Postman 10及以上版本。

内容的提问来源于stack exchange，提问作者Igor Martakov