Issue with ZodSchema when using template literal types (e.g., p${string})

[MineYuanlu]

I am trying to define a Zod schema for a type based on a template literal (e.g., p${string}) and use it in a generateJsonSchema function, but I am running into a TypeScript type error.

Here is the example code I am working with:

import zodToJsonSchema from 'zod-to-json-schema';

type pStr = `p${string}`;

function generateJsonSchema<T>(t: z.ZodSchema<T>) { return zodToJsonSchema(t) }

generateJsonSchema<pStr>(z.string().refine((v): v is pStr => v.startsWith('p').describe('project ID')));

This results in the following TypeScript error:

Type 'ZodEffects<ZodString, `p${string}`, string>' is not assignable to type 'ZodType<`p${string}`, ZodTypeDef, `p${string}`>'.
  Property '_input' is incompatible.
    Type 'string' is not assignable to type '`p${string}`'. ts(2345)

Issue:

I am trying to define a refined Zod schema for a type like pStr (which is a template literal type p${string}). However, TypeScript complains about the incompatibility between string and the template literal type when trying to pass the schema to the generateJsonSchema function.

I would like to know:

• Is there a way to work around this issue while still using template literal types in Zod schemas?
• Is there a way to generate a JSON schema for a refined type like pStr?

The goal is to provide a type (like pStr) and have Zod output the corresponding JSON schema, either manually or automatically, without running into this TypeScript compatibility error.

Environment:

• Zod version: 3.24.1
• TypeScript version: 5.0.0