@p4ck493/ts-type-guard NPM

ts-type-guard

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💡 Idea

The idea is to make a decorator for the method that will check the input and output data of the method with the possibility of writing your own check methods or using ready ones from another package.

📝 Table of contents

ts-type-guard

💿 Installation

npm install @p4ck493/ts-type-guard

// If you don`t want to write your own checks, download this package
npm install @p4ck493/ts-is

🙌 Usage

Import

import {TypeGuard} from "@p4ck493/ts-type-guard";

Example

import {TypeGuard} from '@p4ck493/ts-type-guard';
import {is} from '@p4ck493/ts-is';

class Class {
    #variable;
    
    @TypeGuard([is.string, is.not.null.or.undefined, is.number, null])
    exampleWithArguments(argument1, argumnt2, argument3, argument4?) {
        return arguments;
    }
    
    @TypeGuard({
        arguments: [is.string],
        result: [is.boolean]
    })
    exampleWithResultAndArguments(argument) {
        try {
            this.#variable = JSON.parse(argument);
            return true;
        } catch(e) {
            return false;
        }
    }

    // If you need to skip some argument from the validation, also an alternative to NULL is an empty array []
    @TypeGuard([is.number, null, is.string])
    exampleWithSkupArgumentCheck(one: number, two: any, three: string) {
        // ...
    }

    // If you write only one method, it will be used to check each argument
    @TypeGuard([is.number])
    exampleWithOneCheckersForEachArgument(one: number, two: number, three: number) {

    }

    // Alternative for prev. example
    @TypeGuard({
        arguments: [is.not.null.or.undefined],
    })
    exampleAlternativeOfUsing(one: number, two: number, three: number) {

    }

    // If you need to turn off the error message
    @TypeGuard({
        errorType: ErrorTypeEnum.NONE, // VARIANTS: THROW, NONE
        arguments: [is.not.null.or.undefined],
    })
    exampleOfTurningOffErrorMessage(one: number, two: number, three: number) {

    }
}

const cl: Class = new Class();
cl.exampleWithResultAndArguments({bad: 'value'}) // Bad
cl.exampleWithResultAndArguments('') // Good