valid-value

Extendable validation utility library for typescript and javascript

Getting Started

# Install the package 
npm install --save valid-value
 
# Or use yarn 
Yarn add valid-value
 

Contributing

# Fork and clone the repository 
git clone https://github.com/<GITHUB_USERNAME>/valid-value.git
 
# Move into the directory 
cd valid-value
 
# Add the main repository as your upstream remote 
git remote add upstream https://github.com/ShaunLloyd/valid-value.git

Before contributing, please:

• Make sure there is a github issue requesting your fix / addition. This can be from you or someone else.

• Make sure your new code is tested

• Make sure your branch is up to date with the current master branch

Documentation

isValueValid(value: string, validators: ValidatorOrKeyArray) => boolean

Params:

• value - string: The string value for validation
• validators - Array: An array of strings keys for the included validators and custom validator functions

Returns: boolean

Basic Example:

This package comes with some built in validators. To use them, add the names of those validators to the validator array. Check our full list of built in validators here

import { isValueValid } from 'valid-value';
 
const isValid = isValueValid('test-string', ['required']);
 
console.log(isValid) // => returns true

Custom Validator Example:

Adding custom validation rules is easy. Add a function that takes in a string value and returns a boolean.

import { isValueValid } from 'valid-value';
 
const isValid = isValueValid('test-4-string', [
  value => !/\d/.test(value), // string must not contain numbers
]);
 
console.log(isValid) // => returns false

Built In Validators

There are a list of built in validators to use

Validator Key	Description
'required'	String length must be greater than zero
'noWhiteSpace'	String must not include any whitespace characters including space, tab, and newline

Validator Helpers

There is also a collection of helper functions to create validators that can be used

minimumLength(min: number)

Params:

• min - number: the minimum length of value

Returns: (value: string): boolean => value.length >= min

minimumLength is a function that takes in a number and returns a validator function that checks the string value length is greater than or equal to the given number.

Example:

import { isValueValid } from 'valid-value';
import { minimumLength } from 'valid-value/helpers';
 
const isValid = isValueValid('test string', [
  // returns a validator to check for
  // a minimum length of 5
  minimumLength(5)
]);

---

maximumLength(max: number)

Params:

• max - number: the maximum length of value

Returns: (value: string): boolean => value.length <= max

maximumLength is a function that takes in a number and returns a validator function that checks the string value length is less than or equal to the given number.

Example:

import { isValueValid } from 'valid-value';
import { maximumLength } from 'valid-value/helpers';
 
const isValid = isValueValid('test string', [
  // returns a validator to check for
  // a maximum length of 15
  maximumLength(15)
]);

---

lengthInRange(min: number, max: number)

Params:

• min - number: the minimum length of value
• max - number: the maximum length of value

Returns: (value: string): boolean => value.length >= min && value.length <= max

lengthInRange is a function that takes in a minimum and maximum length and returns a validator function that checks the string value length is with in range of the minimum and maximum values inclusive.

Example:

import { isValueValid } from 'valid-value';
import { lengthInRange } from 'valid-value/helpers';
 
const isValid = isValueValid('test string', [
  // returns a validator to check for a length
  // between 5 and 15 inclusive
  lengthInRange(5, 15)
]);

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