feat: allow x-zod-schema extension property in openapi docs to override generated schema

[h-sigma]

What it does

Allows the user to override the zod schema generated for an openapi schema via an extension property:

NullableDateTime:
      description: Date and time in ISO 8601 format, or null.
      type: [string, "null"]
      format: date-time
      x-zod-schema: z.coerce.date().nullable()

This should generate:

const NullableDateTime = z.coerce.date().nullable();

Enable It Via

The new CLI option: --x-zod-schema.

Reasoning

Tweaking the generated client via only handlebars is... quite limiting. In cases where there is a conflict between the spec author/developer and the openapi-zod-client plugin in terms of what should be generated, or when the generator turns out to be inflexible, this extension can provide a much cheaper alternative to forking the project.

Take my example above: I wanted coercion on my date types because js Date class is what I like to use in my form components. That's not possible out of the box with the plugin. In fact, I dropped my attempt at modifying the library to add an option for coercions halfway through and wrote this instead.

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Name	Status	Preview	Comments	Updated (UTC)
openapi-zod-client	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Nov 30, 2023 6:34am

[astahmer]

hey, adding an escape hatch seems like a good idea, can you add a test and a changeset ?

[h-sigma]

definitely. but it'll have to be after today's work day or tomorrow.
@astahmer
I notice there is code to emit types, e.g. in the template

export const {{@key}}{{#if (lookup ../emittedType @key)}}: z.ZodType<{{@key}}>{{/if}} = {{{this}}};

apparently to aid with circular type dependencies.
Will the code in openApiToTypescript.ts be needed to be changed in order to accommodate this feature?

[astahmer]

Will the code in openApiToTypescript.ts be needed to be changed in order to accommodate this feature?

hm I don't think so since you only want to override the zod schemas ? or maybe you'd also like to make a x-ts-schema in case the zod schema differs too much from the generated TS type ?

[astahmer]

I'm not sure, is it ready to be merged ?

[ecamellini]

Hi all, are there updates on this PR? I have the same need on some projects I'm working on 😇

[astahmer]

feel free to take over the PR and update it so it can be merged