honojs-middleware/packages/zod-validator/src/index.ts

87 lines
2.6 KiB
TypeScript

import type { Context, Env, Input, MiddlewareHandler, TypedResponse, ValidationTargets } from 'hono'
import { validator } from 'hono/validator'
import { ZodObject } from 'zod'
import type { ZodError, ZodSchema, z } from 'zod'
export type Hook<
T,
E extends Env,
P extends string,
Target extends keyof ValidationTargets = keyof ValidationTargets,
O = {}
> = (
result: ({ success: true; data: T } | { success: false; error: ZodError; data: T }) & {
target: Target
},
c: Context<E, P>
) => Response | void | TypedResponse<O> | Promise<Response | void | TypedResponse<O>>
type HasUndefined<T> = undefined extends T ? true : false
export const zValidator = <
T extends ZodSchema,
Target extends keyof ValidationTargets,
E extends Env,
P extends string,
In = z.input<T>,
Out = z.output<T>,
I extends Input = {
in: HasUndefined<In> extends true
? {
[K in Target]?: In extends ValidationTargets[K]
? In
: { [K2 in keyof In]?: ValidationTargets[K][K2] }
}
: {
[K in Target]: In extends ValidationTargets[K]
? In
: { [K2 in keyof In]: ValidationTargets[K][K2] }
}
out: { [K in Target]: Out }
},
V extends I = I
>(
target: Target,
schema: T,
hook?: Hook<z.infer<T>, E, P, Target>
): MiddlewareHandler<E, P, V> =>
// @ts-expect-error not typed well
validator(target, async (value, c) => {
let validatorValue = value
// in case where our `target` === `header`, Hono parses all of the headers into lowercase.
// this might not match the Zod schema, so we want to make sure that we account for that when parsing the schema.
if (target === 'header' && schema instanceof ZodObject) {
// create an object that maps lowercase schema keys to lowercase
const schemaKeys = Object.keys(schema.shape)
const caseInsensitiveKeymap = Object.fromEntries(
schemaKeys.map((key) => [key.toLowerCase(), key])
)
validatorValue = Object.fromEntries(
Object.entries(value).map(([key, value]) => [caseInsensitiveKeymap[key] || key, value])
)
}
const result = await schema.safeParseAsync(validatorValue)
if (hook) {
const hookResult = await hook({ data: validatorValue, ...result, target }, c)
if (hookResult) {
if (hookResult instanceof Response) {
return hookResult
}
if ('response' in hookResult) {
return hookResult.response
}
}
}
if (!result.success) {
return c.json(result, 400)
}
return result.data as z.infer<T>
})