API 契约测试引擎（专业版）

输入

check_contract(actual, expected)；is_contract_valid(problems)
expected 叶子值为类型字符串，嵌套结构用 dict 递归。

输出

问题元组列表 (kind,path,expected,actual)；契约是否通过 bool

硬性规则

1. 三类问题：missing/type_mismatch/extra，路径以 $.字段 定位。
2. boolean 与 integer 分别判定，不混为数字。
3. 仅 missing/type_mismatch 阻断；extra 不阻断。

示例

check_contract({{"id":1}},{{"id":"integer","name":"string"}}) → 含 missing $.name
is_contract_valid([("extra","$.remark",None,None)]) → True

Python 引擎（可独立运行）

# -*- coding: utf-8 -*-
def _typeof(v):
    if isinstance(v, bool): return "boolean"
    if isinstance(v, int): return "integer"
    if isinstance(v, float): return "number"
    if isinstance(v, str): return "string"
    if isinstance(v, list): return "array"
    if isinstance(v, dict): return "object"
    if v is None: return "null"
    return "unknown"

def check_contract(actual, expected):
    """递归比对响应与契约。expected 值为类型字符串；嵌套 dict 递归。
    返回问题列表：missing(缺字段)/type_mismatch(类型不符)/extra(多余字段,不阻断)。"""
    problems = []
    def walk(a, e, path="$"):
        if isinstance(e, dict):
            if not isinstance(a, dict):
                problems.append(("type_mismatch", path, "object", _typeof(a))); return
            for k, t in e.items():
                kp = f"{path}.{k}"
                if k not in a:
                    problems.append(("missing", kp, t, None)); continue
                if isinstance(t, dict):
                    walk(a[k], t, kp)
                elif _typeof(a[k]) != t:
                    problems.append(("type_mismatch", kp, t, _typeof(a[k])))
            for k in a:
                if k not in e:
                    problems.append(("extra", f"{path}.{k}", None, None))
        elif _typeof(a) != e:
            problems.append(("type_mismatch", path, e, _typeof(a)))
    walk(actual, expected)
    return problems

def is_contract_valid(problems):
    """missing/type_mismatch 阻断；extra(向后兼容新增字段)不阻断。"""
    return not any(p[0] in ("missing", "type_mismatch") for p in problems)