The result of zod.preprocess v3.22.2 is ignored and falls back to the original value inside a further refine

[azhiv]

This code is on sandbox. We noticed this behaviour in v3.22.2.

const schema = zod
  .object({
    inactiveObject: zod
      .object({
        isInactive: zod.boolean(),
      })
      .refine(
        ({ isInactive }) => isInactive === false, // <-- This refine fails leading to the preprocess below to be ignored
        { message: 'object is inactive' }
      ),
    arr: zod.preprocess((val) => [val], zod.array(zod.object({}))), // <-- The result of this code is ignored, `arr` remains `val` in the refine below
  })
  .refine(({ arr }) => arr.some((elem) => elem !== null)); // arr.some is not a function

schema.safeParse({
  inactiveObject: {
    isInactive: true,
  },
  arr: {},
});

I debugged the code and it turns out the bug occurs here:

if (effect.type === "preprocess") {
  const processed = effect.transform(ctx.data, checkCtx);
  if (ctx.common.issues.length) {
      return {
          status: "dirty",
          value: ctx.data
      };
  }
...

-- the result of transform is ignored. This condition was absent in v.3.21.4 which worked fine for the usecase above.

[JacobWeisenburger]

Perhaps using transform and pipe will work for you instead?

const schema = z.object( {
    inactiveObject: z.object( { isInactive: z.boolean() } ).refine(
        ( { isInactive } ) => isInactive === false,
        'object is inactive'
    ),
    arr: z.any().transform( x => [ x ] ).pipe( z.object( {} ).array() ),
} ).refine( ( { arr } ) => arr.some( x => x !== null ) )

const result = schema.safeParse( {
    inactiveObject: {
        isInactive: true,
    },
    arr: {},
} )
!result.success && console.log( result.error.issues )
// [
//     {
//         code: "custom",
//         message: "object is inactive",
//         path: [ "inactiveObject" ]
//     }
// ]

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[andreyfel]

The issue seems to be fixed with v3.23.0 by #2912