SyntaxError: A 'const' initializer in an ambient context must be a string or numeric literal or literal enum reference

[Christian-Harnisch-DB]

Bug description

I'm trying to generate Zod schemas from a types.d.ts file. However, no output file is written and the error message "SyntaxError: A 'const' initializer in an ambient context must be a string or numeric literal or literal enum reference" is logged. This seems to be related to the input file being a d.ts file, but my experience with TypeScript is rather limited so I don't know what the actual issue is.

Input

This file from prometheus-query-js. The (Powershell) CLI command is npx ts-to-zod .\node_modules\prometheus-query\dist\types.d.ts .\build\types.zod.ts. Adding --skipValidation to the CLI command just suppresses the line "√ Validating generated types".

Expected output

A file with Zod schemas

Actual output

√ Validating generated types
    SyntaxError: A 'const' initializer in an ambient context must be a string or numeric literal or literal enum reference. (5:43)
      3 | import { ResponseType } from "./../node_modules/prometheus-query/dist/types.d";
      4 |
    > 5 | export declare const responseTypeSchema = z.nativeEnum(ResponseType);
        |                                           ^
      6 |
      7 | export declare const serieSelectorSchema = z.union([z.string(), z.array(z.string())]);
      8 |

Versions

• Typescript: v5.6.2
• Zod: v3.23.8
• ts-to-zod: v3.14.1

[tvillaren]

Hello,

I've never used the lib with a d.ts type declaration file but:

• it seems the declare keyword causes the error you encounter (was able to reproduce with only one type declaration)
• even it ts-to-zod could handle it (which should not be too hard to add), the file you mention contains class declarations which are not supported yet by the lib (see https://github.com/fabien0102/ts-to-zod/issues/268): we only support the interface part of classes, not the z.instanceof equivalent.