discriminated union with dataType json causing SchemaError

[konstantinblaesi]

Error trace

SchemaError: [addresses.additional.name] No default value specified for field (can be undefined, but must be explicit)
    at Defaults_traverseAndReplace (/projects/sveltekit-superforms/src/lib/errors.ts:290:11)
    at Errors_traverseAndReplace (/projects/sveltekit-superforms/src/lib/errors.ts:237:4)
    at Data_traverse (/projects/sveltekit-superforms/src/lib/errors.ts:221:3)
    at Module.replaceInvalidDefaults (/projects/sveltekit-superforms/src/lib/errors.ts:303:10)
    at Module.superValidate (/projects/sveltekit-superforms/src/lib/superValidate.ts:139:5)
    at /projects/sveltekit-superforms/src/tests/demo.test.ts:55:13
    at runTest (file:///projects/sveltekit-superforms/node_modules/.pnpm/@[email protected]/node_modules/@vitest/runner/dist/index.js:781:11)
    at runSuite (file:///projects/sveltekit-superforms/node_modules/.pnpm/@[email protected]/node_modules/@vitest/runner/dist/index.js:909:15)
    at runSuite (file:///projects/sveltekit-superforms/node_modules/.pnpm/@[email protected]/node_modules/@vitest/runner/dist/index.js:909:15)
    at runFiles (file:///projects/sveltekit-superforms/node_modules/.pnpm/@[email protected]/node_modules/@vitest/runner/dist/index.js:958:5) {
  path: 'addresses.additional.name'
}

From the repro: The testcase bad produces this error trace, testcase good works
Basically the feature is to provide one of three possible address types, something like

addresses.additional.type = { 'type1', 'type2', 'none' }

where the 'none' type has no additional fields

Repro

Code

import { zod } from "$lib/adapters/zod.js";
import { superValidate } from "$lib/superValidate.js";
import { describe, test } from 'vitest';
import { z } from "zod";


describe("Demo", () => {
    test("Bad", async () => {
        const schema = zod(
            z.object({
                addresses: z.object({
                    additional: z.discriminatedUnion('type', [
                        z.object({
                            type: z.literal('poBox'),
                            name: z.string().min(1, 'err min len').max(10, 'err max len')
                        }),
                        z.object({
                            type: z.literal('none'),
                        }),
                    ]).default({ type: 'none' })
                })
            })
        )

        const formInput = new FormData()
        formInput.set(
            '__superform_json',
            JSON.stringify([
                {
                    addresses: 1
                },
                {
                    additional: 2
                },
                {
                    type: 3,
                    name: 4
                },
                'poBox',
                ''
            ])
        )
        try {
            await superValidate(formInput, schema)
        } catch (err) {
            console.error(err)
            //
            throw err
        }
    })

    test("Good", async () => {
        const schema = zod(
            z.object({
                addresses: z.object({
                    additional: z.discriminatedUnion('type', [
                        z.object({
                            type: z.literal('poBox'),
                            name: z.string().min(1, 'err min len').max(10, 'err max len')
                        }),
                        z.object({
                            type: z.literal('none'),
                        }),
                    ]).default({ type: 'poBox', name: '' })
                })
            })
        )

        const formInput = new FormData()
        formInput.set(
            '__superform_json',
            JSON.stringify([
                {
                    addresses: 1
                },
                {
                    additional: 2
                },
                {
                    type: 3,
                    name: 4
                },
                'poBox',
                ''
            ])
        )
        try {
            await superValidate(formInput, schema)
        } catch (err) {
            console.error(err)
            throw err
        }
    })
})

Should this kind of schema work ? Should this be modeled differently?

[ciscoheat]

You can't stringify __superform_json directly, you need to use devalue. Try that and see if it works. Otherwise you should try to add a default value to the schema, as suggested by the error.