@prairielearn/zod

Useful Zod schemas.

Usage

Express request validation

Use parseRequest to validate any combination of Express path parameters, query parameters, and request body. Request schemas that do not depend on request-time values should be defined at module scope so their Zod instances are reused.

import { z } from 'zod';

import { IdSchema, parseRequest } from '@prairielearn/zod';

const PostRequestSchemas = {
  params: z.object({ course_id: IdSchema }),
  body: z.discriminatedUnion('__action', [
    z.object({
      __action: z.literal('rename'),
      name: z.string().min(1),
    }),
    z.object({ __action: z.literal('delete') }),
  ]),
};

const { params, body } = parseRequest(req, PostRequestSchemas);

Validation failures throw a 400 HttpStatusError with a source-specific message. An unrecognized discriminator in a top-level z.discriminatedUnion('__action', ...) body schema is reported as unknown __action: <value>; other body failures are reported as Invalid request body.

Use parseRequestParams, parseRequestQuery, or parseRequestBody when validating a single request data source.

BooleanFromCheckboxSchema

import { BooleanFromCheckboxSchema } from '@prairielearn/zod';

BooleanFromCheckboxSchema.parse(''); // false
BooleanFromCheckboxSchema.parse('true'); // true
BooleanFromCheckboxSchema.parse('1'); // true
BooleanFromCheckboxSchema.parse('on'); // true

DatetimeLocalStringSchema

import { DatetimeLocalStringSchema } from '@prairielearn/zod';

DatetimeLocalStringSchema.parse('2024-01-15T14:30'); // '2024-01-15T14:30:00'
DatetimeLocalStringSchema.parse('2024-01-15T14:30:45'); // '2024-01-15T14:30:45'

UniqueUidsFromStringSchema

import { UniqueUidsFromStringSchema } from '@prairielearn/zod';

const schema = UniqueUidsFromStringSchema();
schema.parse('[email protected], [email protected]'); // ['[email protected]', '[email protected]']
schema.parse('[email protected] [email protected]'); // ['[email protected]'] (deduplicated)