Prisma Enum Validator Generator

This package will generate enum validation methods from your schema.prisma file.

1. Installation
2. Usage
3. Configuration
   1. Using With Javascript

Installation

npm i -D prisma-enum-validator-generator

Add the following to your schema.prisma

generator erd {
  provider = "prisma-enum-validator-generator"
}

Run the generator

npx prisma generate

The following enum:

enum Colors {
  RED
  BLUE
  GREEN
}

will result in the following code:

/**
 * A function to validate if a string is of type {@link Colors}.
 * @param {string | null | undefined} value The value to test.
 * @returns {boolean} `true` if {@link value} is of type {@link Colors}. Otherwise `false`.
 */
export function isColors(value: string | null | undefined): value is Colors {
	if (!value) return false;
	return Object.values(Colors).includes(value as Colors);
}

Usage

To use the validation functions you simply import the one you need from the generated file. The functions are type guards, which means that their return value is boolean but they also modify the type of the the argument that you pass.

import { isColors } from '../prisma/enum-validators';

function someFunction(str: string | null) {
	if (isColors(str)) {
		// str: Colors
	}

	// str: string | null
}

Configuration

The generator provides the following configurations:

generator erd {
  provider = "prisma-enum-validator-generator"
  output = string //Specifies where the validators file will be generated. Defaults to 'enum-validators.ts'.
  isTs = boolean //Specifies whether the output is targeted for typescript or javascript. Defaults to true.
}

Using with Javascript

The generator also supports outputting to javascript format. By setting isTs to false, all typescript exclusive syntax will be removed, allowing you to use the validation functions in your javascript project.

Typescript output:

/**
 * A function to validate if a string is of type {@link Colors}.
 * @param {string | null | undefined} value The value to test.
 * @returns {boolean} `true` if {@link value} is of type {@link Colors}. Otherwise `false`.
 */
export function isColors(value: string | null | undefined): value is Colors {
	if (!value) return false;
	return Object.values(Colors).includes(value as Colors);
}

Javascript output:

/**
 * A function to validate if a string is of type {@link Colors}.
 * @param {string | null | undefined} value The value to test.
 * @returns {boolean} `true` if {@link value} is of type {@link Colors}. Otherwise `false`.
 */
export function isColors(value) {
	if (!value) return false;
	return Object.values(Colors).includes(value);
}

** Note that setting isTs to false, will change any output filename extension to .js