Zod Helper

zod-v3.ts

import {
  z,
  ZodArray,
  ZodBoolean,
  ZodDefault,
  ZodEffects,
  ZodEnum,
  ZodLiteral,
  ZodNumber,
  ZodObject,
  ZodOptional,
  ZodRawShape,
  ZodRecord,
  ZodString,
  ZodUnion,
} from 'zod';

// Helper type to extract initial values type from a Zod schema
type InitialValues<T extends ZodRawShape> = {
  [K in keyof T]: T[K] extends ZodDefault<any>
  ? ReturnType<T[K]['_def']['defaultValue']>
  : T[K] extends ZodOptional<any>
  ? undefined
  : T[K] extends ZodBoolean
  ? boolean
  : T[K] extends ZodString
  ? string
  : T[K] extends ZodNumber
  ? number
  : T[K] extends ZodArray<any>
  ? Array<z.infer<T[K]['element']>>
  : T[K] extends ZodObject<any>
  ? InitialValues<T[K]['shape']>
  : T[K] extends ZodRecord<any>
  ? Record<string, any>
  : T[K] extends ZodEnum<any>
  ? T[K]['_def']['values'][number]
  : T[K] extends ZodUnion<any>
  ? z.infer<T[K]>
  : T[K] extends ZodLiteral<any>
  ? T[K]['_def']['value']
  : null;
};

function unwrapEffects(schema: any): any {
  while (schema instanceof ZodEffects) {
    schema = schema._def.schema;
  }
  return schema;
}

export const extractInitialValues = <T extends ZodRawShape>(
  schema: ZodObject<T> | ZodEffects<ZodObject<T>>
): InitialValues<T> => {
  const unwrapped = unwrapEffects(schema) as ZodObject<T>;
  const shape = unwrapped.shape;
  const initialValues: Record<string, any> = {};

  for (const [key, value] of Object.entries(shape)) {
    const field = unwrapEffects(value);

    if (field instanceof ZodDefault) {
      initialValues[key] = field._def.defaultValue();
    } else if (field instanceof ZodOptional) {
      initialValues[key] = undefined;
    } else if (field instanceof ZodBoolean) {
      initialValues[key] = false;
    } else if (field instanceof ZodString) {
      initialValues[key] = '';
    } else if (field instanceof ZodNumber) {
      initialValues[key] = 0;
    } else if (field instanceof ZodArray) {
      initialValues[key] = [];
    } else if (field instanceof ZodObject) {
      initialValues[key] = extractInitialValues(field);
    } else if (field instanceof ZodRecord) {
      initialValues[key] = {};
    } else if (field instanceof ZodEnum) {
      initialValues[key] = field._def.values[0]; // Pick first enum value as default
    } else if (field instanceof ZodLiteral) {
      initialValues[key] = field._def.value;
    } else if (field instanceof ZodUnion) {
      initialValues[key] = null; // Unions are tricky; default to null
    } else {
      initialValues[key] = null;
    }
  }

  return initialValues as InitialValues<T>;
};

export function createZodField(
  fieldName: string,
  props?: {
    min?: number;
    max?: number;
    customMessage?: string;
    type?: 'string' | 'number';
  },
) {
  const displayName = fieldName
    .replace(/_/g, ' ')
    .replace(/\b\w/g, l => l.toUpperCase());
  const requiredMsg = props?.customMessage || `${displayName} is required`;
  const min = props?.min ?? 1;
  const type = props?.type ?? 'string';
  const params = {
    required_error: requiredMsg,
    invalid_type_error: requiredMsg,
  };

  let result = (type === 'string' ? z.string(params) : z.number(params)).min(
    min,
    min > 1
      ? `${displayName} must be at least ${min}${type === 'string' ? ' characters' : ''
      }`
      : requiredMsg,
  );

  if (props?.max) {
    result = result.max(
      props.max,
      `${displayName} must be at most ${min}${type === 'string' ? ' characters' : ''
      }`,
    );
  }

  return result;
}

zod.ts

import {
  z,
  ZodArray,
  ZodBoolean,
  ZodDefault,
  ZodEnum,
  ZodLiteral,
  ZodNumber,
  ZodObject,
  ZodOptional,
  ZodRawShape,
  ZodRecord,
  ZodString,
  ZodUnion,
} from 'zod';

// Helper type to extract initial values type from a Zod schema
type InitialValues<T extends ZodRawShape> = {
  [K in keyof T]: T[K] extends ZodDefault<any>
    ? ReturnType<T[K]['_def']['defaultValue']>
    : T[K] extends ZodOptional<any>
      ? undefined
      : T[K] extends ZodBoolean
        ? boolean
        : T[K] extends ZodString
          ? string
          : T[K] extends ZodNumber
            ? number
            : T[K] extends ZodArray<any>
              ? Array<z.infer<T[K]['element']>>
              : T[K] extends ZodObject<any>
                ? InitialValues<T[K]['shape']>
                : T[K] extends ZodRecord<any>
                  ? Record<string, any>
                  : T[K] extends ZodEnum<any>
                    ? T[K]['def']['entries'][number]
                    : T[K] extends ZodUnion<any>
                      ? z.infer<T[K]>
                      : T[K] extends ZodLiteral<any>
                        ? T[K]['def']['values'][number]
                        : null;
};

export const extractInitialValues = <T extends ZodRawShape>(
  schema: ZodObject<T>,
): InitialValues<T> => {
  const shape = schema.shape;
  const initialValues: Record<string, any> = {};

  for (const [key, value] of Object.entries(shape)) {
    const field = value;
    if (field instanceof ZodDefault) {
      // @ts-ignore
      initialValues[key] = field.def.defaultValue();
    } else if (field instanceof ZodOptional) {
      initialValues[key] = undefined;
    } else if (field instanceof ZodBoolean) {
      initialValues[key] = false;
    } else if (field instanceof ZodString) {
      initialValues[key] = '';
    } else if (field instanceof ZodNumber) {
      initialValues[key] = 0;
    } else if (field instanceof ZodArray) {
      initialValues[key] = [];
    } else if (field instanceof ZodObject) {
      initialValues[key] = extractInitialValues(field);
    } else if (field instanceof ZodRecord) {
      initialValues[key] = {};
    } else if (field instanceof ZodEnum) {
      initialValues[key] = field.def.entries[0];
    } else if (field instanceof ZodLiteral) {
      initialValues[key] = field.def.values[0];
    } else if (field instanceof ZodUnion) {
      initialValues[key] = null; // Unions are tricky; default to null
    } else {
      initialValues[key] = null;
    }
  }

  return initialValues as InitialValues<T>;
};

export function createZodField(
  fieldName: string,
  props?: {
    min?: number;
    max?: number;
    customMessage?: string;
    type?: 'string' | 'number';
  },
) {
  const displayName = fieldName
    .replace(/_/g, ' ')
    .replace(/\b\w/g, l => l.toUpperCase());
  const requiredMsg = props?.customMessage || `${displayName} is required`;
  const min = props?.min ?? 1;
  const type = props?.type ?? 'string';
  const params = {
    required_error: requiredMsg,
    invalid_type_error: requiredMsg,
  };

  let result = (type === 'string' ? z.string(params) : z.number(params)).min(
    min,
    min > 1
      ? `${displayName} must be at least ${min}${type === 'string' ? ' characters' : ''
      }`
      : requiredMsg,
  );

  if (props?.max) {
    result = result.max(
      props.max,
      `${displayName} must be at most ${min}${type === 'string' ? ' characters' : ''
      }`,
    );
  }

  return result;
}