如何使用JSON Schema实现跨对象属性名的匹配校验

JSON Schema 完全支持这类跨字段属性名匹配校验，VS Code 内置的JSON校验引擎默认兼容所需规则，无需额外插件，对你现有Schema做少量修改即可实现需求。

具体修改步骤 #

1. 指定Schema版本
   在你的Schema根节点添加$schema字段，声明使用2019-09及以上版本规范，避免校验器默认用旧版解析导致规则失效：

   "$schema": "https://json-schema.org/draft/2020-12/schema",
   

2. 抽离统一的角色标签规则
   在根节点添加$defs字段定义角色标签的通用格式规则，同时修正你原有Schema里的规则位置错误：你之前把minItems、uniqueItems这类约束数组本身的规则写在了items（数组元素约束）里，这部分规则不会生效，需要挪到数组定义的同级位置。
   先添加通用标签定义：

   "$defs": {
     "characterTag": {
       "type": "string",
       "title": "Character tag",
       "description": "Short identifier for a character",
       "pattern": "^[a-z0-9_]+$"
     }
   }
   

   再修改characters字段的配置，给属性名增加格式约束：

   "characters": {
     "title": "Character collection",
     "description": "A collection of the available characters.",
     "type": "object",
     "propertyNames": { "$ref": "#/$defs/characterTag" },
     "additionalProperties":{
       "title": "Character entry",
       "type": "object",
       "properties": {
         "name": {
           "title": "Character name",
           "description": "Display name of the character.",
           "type": "string"
         },
         "hex_colour": {
           "title": "Character colour",
           "description": "Hex colour code in 0x000000 format.",
           "type": "string"
         },
         "image_url": {
           "title": "Character image",
           "description": "Public URL to the character's avatar.",
           "type": "string"
         }
       },
       "required": ["name"],
       "additionalProperties": false
     }
   }
   

3. 给quotes对象增加属性名约束
   修改reactions数组项内quotes字段的规则，通过propertyNames+$data引用，强制要求quotes下的所有属性名必须是characters对象中已经定义过的角色标签，同时修正数组规则的位置：

   "quotes": {
     "title": "Quotes collection",
     "description": "Character mapped quote list for the reaction.",
     "type": "object",
     "propertyNames": {
       "$data": "/characters/propertyNames"
     },
     "additionalProperties":{
       "title":"Character quote list",
       "type": "array",
       "minItems": 1,
       "uniqueItems": true,
       "items": {
         "title": "Quote",
         "description": "Reply content sent when the keyword is triggered.",
         "type": "string"
       }
     }
   }
   

   顺便把同层级的keywords字段的规则位置也修正：

   "keywords": {
     "title": "Keyword list",
     "description": "List of trigger keywords for this reaction.",
     "type": "array",
     "minItems": 1,
     "uniqueItems": true,
     "items": {
       "title": "Keyword",
       "type": "string"
     }
   }
   

校验效果 #

修改完成后，只要你在quotes里填写了未在characters中定义的角色标签，VS Code会直接标红提示属性名非法；Python端如果用jsonschema 4.0+版本做运行时校验，默认支持该规则，不需要额外配置。

内容的提问来源于stack exchange，提问作者stebo