Object with Generic Properties makes the properties optional #3334

agarwalvaibhav0211 · 2024-03-18T14:08:24Z

In the following code, if I use generic parameters to create some validators, as in ValidatorFactory, this makes all the non static properties optional. Is this a limitation on Typescript or Zod?

import { AnyZodObject, ZodType, z } from "zod";

type allowedStandardStringEnum=Record<string, string>
type EnumValues<Enum extends allowedStandardStringEnum> = Enum[keyof Enum]

function stringEnumValidator<Enum extends allowedStandardStringEnum>(enumParam:Enum):ZodType<EnumValues<Enum>>{
	return z.nativeEnum(enumParam);
}

function ValidatorFactory<StateEnum extends allowedStandardStringEnum, ZodDataObject extends AnyZodObject>(
	states:StateEnum,
	validator:ZodDataObject,
){
	return z.object({
    staticProp: z.string(),
		currentState    : stringEnumValidator(states),
		dataForFunction : z.unknown(),
		stateData       : validator,
	})
}

type FactoryReturn<StateEnum extends allowedStandardStringEnum, ZodDataObject extends AnyZodObject>=z.infer<ReturnType<typeof ValidatorFactory<StateEnum,ZodDataObject>>>


function execution<StateEnum extends allowedStandardStringEnum, ZodDataObject extends AnyZodObject>(instance:FactoryReturn<StateEnum, ZodDataObject>){
  let staticProp=instance.staticProp                // Correct
  let currentState=instance.currentState            // Incorrect
  let dataForFunction=instance.dataForFunction      // Incorrect
  let stateData=instance.stateData                  // Incorrect
}

I believe it may also be similar to #2077

Also believing that it may be caused by #3330, I can verify that "strict":true has been set in tsconfig.json

Thanks in Advance for any help

The text was updated successfully, but these errors were encountered:

YogaLin · 2024-03-20T11:30:18Z

Same here, but then I found out compilerOptions.strictNullChecks was set to false by another tsconfig.json file I extend. Setting "strict": true, "strictNullChecks": true solve my problem. @agarwalvaibhav0211 I hope this helpful.

agarwalvaibhav0211 · 2024-03-21T05:57:53Z

@YogaLin, While debugging further, I came across something weird, that it's actually the reverse for me. Setting "strict":true causes the data to be optional while setting "strict":false makes it required as expected. I've created 2 live codes you can check below (you can check line 55 on src/index.ts and line 11 of tsconfig.json in both sandboxes). Do you know if there is something wrong with what I'm doing??

strict:true

strict:false

Charly-xepelin · 2024-11-04T16:29:15Z

Having similar issue, the following schema (without any generic):

const sample = z.object({
    name: z.string(),
});

export type SampleInfer = z.infer<typeof sample>;

Produces the type with name as optional:

Actual:

type SampleInfer {
  name?: string;
}

expected:

type SampleInfer {
  name: string;
}

tsconfig.json:

{
  "$schema": "https://json.schemastore.org/tsconfig",

  "compilerOptions": {
    "composite": false,
    "esModuleInterop": true,
    "isolatedModules": true,
    "moduleResolution": "node",
    "noImplicitAny": true,
    "noImplicitThis": false,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "resolveJsonModule": true,
    "strict": true,
    "baseUrl": "./",
    "paths": {
      "@root/*": ["src/*"],
      "@features/*": ["src/features/*"],
      "@shared/*": ["src/shared/*"]
    },

    "allowSyntheticDefaultImports": true,
    "rootDir": ".",
    "declaration": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "forceConsistentCasingInFileNames": false,
    "incremental": true,
    "module": "commonjs",
    "noFallthroughCasesInSwitch": false,
    "outDir": "./dist",
    "removeComments": true,
    "skipLibCheck": true,
    "sourceMap": true,
    "strictBindCallApply": false,
    "strictNullChecks": false,
    "target": "es2022"
  },
  "exclude": ["node_modules", "./dist"]
}

Charly-xepelin · 2024-11-04T16:30:43Z

Changing to "strictNullChecks": true solves the issue.

Sweet-KK · 2025-05-19T03:29:08Z

strictNullChecks
This has led to another extreme where everything has become mandatory. Even if I add "optional", what is expected to be optional is still mandatory, and vice versa.

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Object with Generic Properties makes the properties optional #3334

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