commonbaseapp/zodex

The missing zod (de/)serialization library

Zodex

Type-safe (de)serialization library for zod. It both serializes and simplifies types into a JSON format, in the following ways:

• optional, nullable and default types are inlined into any given types itself

{ "type": "string", "defaultValue": "hi" }

• number checks are also inlined into the type itself

{ "type": "number", "min": 23, "max": 42 }

Installation

pnpm add zodex
# or
yarn add zodex
# or
npm install zodex

Usage

import { z } from "zod";
import { zerialize } from "zodex";

const someZodType = z.discriminatedUnion("id", [
  z.object({ id: z.literal("a"), count: z.number().optional() }),
  z.object({ id: z.literal("b") }),
]);
const shape = zerialize(someZodType);

Now typeof shape will be

type Shape = {
  type: "discriminatedUnion";
  discriminator: "id";
  options: [
    {
      type: "object";
      properties: {
        id: { type: "literal"; value: "a" };
        count: { type: "number"; isOptional: true };
      };
    },
    { type: "object"; properties: { id: { type: "literal"; value: "b" } } }
  ];
};

which is exactly equal to its runtime value (shown in YAML for brevity, you probably shouldn't use YAML):

type: "discriminatedUnion"
discriminator: "id"
options:
  - type: "object"
    properties:
      id:
        type: "literal"
        value: "a"
      count:
        type: "number"
        isOptional: true
  - type: "object"
    properties:
      id:
        type: "literal"
        value: "b"

Options

Both zerialize and dezerialize accept an options object with the same properties.

Since Zod does not allow the specification of the names of effects (refinements, transforms, and preprocesses), we allow you to supply as options maps of names to effects so that these can be part of serialization and deserialization. If none of these options are supplied, the effects will be omitted.

Properties:

• superRefinements - Map of name to .superRefine() functions
• transforms - Map of name to .transform() functions
• preprocesses - Map of name to z.preprocess() functions

Use of JSON References

JSON references are used to represent local references. If you wish to use JSON references for remote (non-cyclic) references, you may do so, but you will need to use a library like json-refs (with resolveRefs) to first resolve such references and then supply the object to dezerialize.

Zodex will serialize local references, including handling recursive ones. As with JSON Schema, the $defs property may be a reasonable top-level property to use as storage for local references, but it receives no special treatment by this library (any property could be targeted by one's references).

Note that if you wish to use additional properties with an item containing a reference, e.g., isOptional, you will first need to wrap the JSON reference within a single-item union such as in the following:

{
  "type": "union",
  "options": [
    {
      "$ref": "#/properties/id"
    }
  ]
}

Note that due to technical limitations with Zod, we are unable to allow a JSON reference in place of an object properties object. You can either resolve this first with another library (if it is a non-cyclic reference), or target the whole object or individual properties.

Roadmap

• custom error messages are not included

Caveats

• brand is not supportable and omitted
• lazy and pipeline types are unwrapped
• catch with a function can have its then-value serialized but it cannot then be deserialized back into using the original function
• Due to technical limitations, we cannot support the regular refine(), custom() and instanceof methods (and they will be ignored), but these are really just implementations of superRefine() which is supported