zenstack-validator

zenstack-validator

ZenStack plugin and decorators for class-validator: Auto-generate DTOs with validation logic directly from your ZModel schema.

Installation

npm install zenstack-validator class-validator class-transformer
# or
pnpm add zenstack-validator class-validator class-transformer
# or
yarn add zenstack-validator class-validator class-transformer

Peer dependencies: This package expects class-validator, class-transformer, and @zenstackhq/sdk to be installed in your project.

ZenStack Plugin (Generate DTOs)

The plugin generates a TypeScript file containing DTO classes—complete with class-validator and class-transformer decorators—based on your ZenStack schema.

1. Register the plugin

Add the plugin to your schema.zmodel:

plugin validator {
  provider = 'zenstack-validator/plugin'
  output = './src/dto'
}

• output (optional): The directory where the dtos.ts file will be generated.
• Default: To zenstack's default generation directory if omitted.

2. Run ZenStack Generate

npx zenstack generate

This will create src/dto/dtos.ts containing your typed DTO classes.

3. Use the generated DTOs

// Import from your generated location
import { UserDTO } from "./src/dto/dtos";

// Example in a NestJS Controller
@Post()
async createUser(@Body() body: UserDTO) {
  console.log(body.email); // Fully typed and validated!
}

Example: Schema → Generated Code

**Input: schema.zmodel**

model User {
   id        String   @id @default(cuid())
   email     String   @email
   name      String?  @trim @lower
   age       Int      @gt(0, "Must be positive") @lte(120)
   createdAt DateTime @default(now())
}

**Output: dtos.ts**

import { IsEmail, IsOptional, IsInt, IsDate, Max } from "class-validator";
import { Type } from "class-transformer";
import { Trim, LowerCase, Gt } from "zenstack-validator";

export class UserDTO {
   @IsEmail()
   email!: string;

   @IsOptional()
   @Trim()
   @LowerCase()
   name?: string;

   @IsInt()
   @Gt(0, { message: "Must be positive" })
   @Max(120)
   age!: number;

   @IsDate()
   @Type(() => Date)
   createdAt!: Date;
}

Custom Decorators API

This package includes custom decorators that cover gaps in the standard class-validator library (like strict inequalities) or provide transformation utilities.

Decorator	Arguments	Description
@Gt	(min: number, options?)	Validates that the value is strictly greater than min.
@Lt	(max: number, options?)	Validates that the value is strictly less than max.
@Trim	()	Trims leading/trailing whitespace (via class-transformer).
@LowerCase	()	Converts string to lowercase (via class-transformer).
@UpperCase	()	Converts string to uppercase (via class-transformer).

Note: Standard validators like @email, @length, @min, @max, and @regex map directly to built-in class-validator decorators.

Package Exports

• Runtime Decorators (Default export): Used by your application at runtime.

import { Gt, Lt, Trim, LowerCase } from "zenstack-validator";

• Generator Plugin: Used by the ZenStack CLI during generation.

// In schema.zmodel
// provider = 'zenstack-validator/plugin'

License

MIT