Zod to MongoDB schema

Converts Zod schemas to MongoDB validation schemas. Inspired by zod-to-json-schema, but became a separate package as the overlap between what MongoDB uses and Draft 7 was deemed to little.

Usage

import { z } from 'zod'
import zodToMongoSchema from 'zod-to-mongodb-schema'
import { ObjectId } from 'wherever' // bson, mongodb, mongoose...

// should also check for typeof value, as isValid also accepts for example numbers
const zodObjectId = z.custom<ObjectId | string>(value => ObjectId.isValid(value))

const userSchema = z.object({
  _id: zodObjectId,
  name: z.string().min(3),
  dateOfBirth: z.date(),
})

const mongoUserSchema = zodToMongoSchema(userSchema, { zodObjectId })

with mongoUserSchema being

// TODO: insert result

Options

Name	Required	Type	Description
zodObjectId	Yes	ZodAnyType	The zod schema you use to validate object ids (for example `z.custom<ObjectId
onUnsupported	No (default: 'warn')	'error' or 'warn' or 'no-op'	How to handle unsupported validations (see below).

Supported validators

For each supported validator, all modifiers which can be implemented in MongoDB are supported (for example z.string().email() is supported by using the RegEx used by zod itself).

Not that unsupported validators can be used in your schema, they will result in {}. If you'd like to receive errors when you're using unsupported validators, see the options above.

Zod	Supported	Remarks
string()	✅	-
number()	✅	Uses bsonType: 'long' for .int().
object()	✅	Sets additionalProperties: false unless .passthrough() is specified.
bigint()	❌	The MongoDB driver doesn't support (de-)serializing BigInt.
boolean()	✅	-
date()	✅	min and max not supported by MongoDB.
undefined()	❌	Flagged as deprecated.
void()	❌	See above.
null()	✅	-
array()	✅	-
union()	WIP	-
discriminatedUnion()	WIP	-
intersection()	WIP	-
tuple()	WIP	-
record()	WIP	-
literal()	WIP	-
enum()	✅	Credit @exsjabe!
nativeEnum()	WIP	-
map()	❌	See bigint().
set()	❌	See bigint().
lazy()	WIP	-
promise()	❌	-
nan()	WIP	Might be possible by using bsonType: 'double' with enum: [ NaN ] but I have no idea how to serialize NaN.
never()	WIP	-
preprocess()	WIP	No-op.
refine()	WIP	No-op.
transform()	WIP	No-op.
function()	WIP	No validation besides it being a function.
symbol()	❌	See undefined().