json-schema-empty-strings/src/lib/json-schema-empty-strings.ts

Generate empty strings for all JSON-Schema string fields.

// Created in 2021-09-25 by Maximillian Dornseif
// Copyright Dr. Maximillian Dornseif 2021

import { JSONSchema7 } from 'json-schema'
import traverse from 'json-schema-traverse'

/** Returns an Object containing `""` for all strings in the Schema.
 */
export function jsonEmptyStrings(schema: JSONSchema7): unknown {
  const ret: Record<string, Record<string, any> | {}> = {}
  traverse(schema, {}, (sch, jsonPtr, _root, parentJsonPtr, _parentKeyword, _parentSchema, indexProperty) => {
    if (jsonPtr.startsWith('/properties/')) {
      // um Nesting korrekt abzubilden müssten wir jsonPtr auseindander pflücken
      if (sch.type === 'object' && indexProperty) {
        ret[indexProperty] = {}
      }

      let destination = ret
      if (parentJsonPtr) {
        for (const subSch of parentJsonPtr.replace(/\/properties/g, '').split('/')) {
          if (subSch === '') {
            continue
          }
          destination[subSch] = destination?.[subSch] || {}
          destination = destination[subSch]
        }
      }
      if (sch.type === 'string' && indexProperty !== undefined) {
        destination[indexProperty] = ''
      }
    }
  })
  return ret
}