JSON Schema 생성기 - JSON 데이터에서 스키마 생성 온라인

// JSON to JSON Schema generator
function jsonToSchema(json, options = {}) {
  const { draft = '2020-12', includeRequired = true, detectFormats = true } = options;
  const schemaUri = {
    'draft-04': 'http://json-schema.org/draft-04/schema#',
    'draft-07': 'http://json-schema.org/draft-07/schema#',
    '2020-12': 'https://json-schema.org/draft/2020-12/schema',
  }[draft];

  function inferSchema(value) {
    if (value === null) return { type: 'null' };
    if (typeof value === 'boolean') return { type: 'boolean' };
    if (typeof value === 'number') {
      return { type: Number.isInteger(value) ? 'integer' : 'number' };
    }
    if (typeof value === 'string') {
      const schema = { type: 'string' };
      if (detectFormats) {
        if (/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}/.test(value)) schema.format = 'date-time';
        else if (/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(value)) schema.format = 'email';
        else if (/^https?:\/\//.test(value)) schema.format = 'uri';
      }
      return schema;
    }
    if (Array.isArray(value)) {
      if (value.length === 0) return { type: 'array', items: {} };
      const itemSchemas = value.map(inferSchema);
      const unique = dedup(itemSchemas);
      return { type: 'array', items: unique.length === 1 ? unique[0] : { oneOf: unique } };
    }
    if (typeof value === 'object') {
      const properties = {};
      const required = [];
      for (const [key, val] of Object.entries(value)) {
        properties[key] = inferSchema(val);
        if (includeRequired && val !== null) required.push(key);
      }
      const schema = { type: 'object', properties };
      if (required.length > 0) schema.required = required;
      return schema;
    }
    return {};
  }

  function dedup(schemas) {
    const seen = new Map();
    for (const s of schemas) {
      const key = JSON.stringify(s);
      if (!seen.has(key)) seen.set(key, s);
    }
    return [...seen.values()];
  }

  const parsed = JSON.parse(json);
  return { $schema: schemaUri, ...inferSchema(parsed) };
}

// Usage
const json = '{"name":"Alice","age":30,"email":"alice@example.com"}';
console.log(JSON.stringify(jsonToSchema(json), null, 2));