Zod .transform() not being called when output="array"

[sp88011]

Description

I noticed that when the output mode is array, then none of the .transform() methods on the schema will be called.

Code example

Here's a relevant example I expect many people to run into (working with dates):

const openAIModel = openai("gpt-4o-mini");

const { object } = await generateObject({
    model: openAIModel,
    output: "array",
    schema: z.object( { date: z.string().transform((x)=>new Date(x)) } ),
    prompt: "Get the date from the text",
  });

While Typescript thinks that object.date is of type Date, in reality it is always of type string. The transformation doesn't happen.

AI provider

10.2.4

Additional context

I tried applying any other transformation, like adding a completely new property but those transformations also don't happen. I believe the entire transform() method is just ignored.