@ai-sdk/provider-utils/src/to-json-schema/zod3-to-json-schema/parsers/map.ts

import type { ZodMapDef } from 'zod/v3';
import { parseDef } from '../parse-def';
import type { JsonSchema7Type } from '../parse-types';
import type { Refs } from '../refs';
import { parseAnyDef } from './any';
import { parseRecordDef, type JsonSchema7RecordType } from './record';

export type JsonSchema7MapType = {
  type: 'array';
  maxItems: 125;
  items: {
    type: 'array';
    items: [JsonSchema7Type, JsonSchema7Type];
    minItems: 2;
    maxItems: 2;
  };
};

export function parseMapDef(
  def: ZodMapDef,
  refs: Refs,
): JsonSchema7MapType | JsonSchema7RecordType {
  if (refs.mapStrategy === 'record') {
    return parseRecordDef(def, refs);
  }

  const keys =
    parseDef(def.keyType._def, {
      ...refs,
      currentPath: [...refs.currentPath, 'items', 'items', '0'],
    }) || parseAnyDef();
  const values =
    parseDef(def.valueType._def, {
      ...refs,
      currentPath: [...refs.currentPath, 'items', 'items', '1'],
    }) || parseAnyDef();
  return {
    type: 'array',
    maxItems: 125,
    items: {
      type: 'array',
      items: [keys, values],
      minItems: 2,
      maxItems: 2,
    },
  };
}