Validators

validators is...

• a minimalistic data validation checker
• fairly efficient (for js).

Usage

Pass in a list of requirements to the createStringValidator or createNumberValidator function:

const passwordValidator = createStringValidator({
  mustContain: ["symbols", "uppercase", "lowercase", "digits"],
  validChars: ["symbols", "alphanumeric"],
  min: 8,
  max: 45,
})

createStringValidator requirements can have the following properties:

• mustContain: Will return error if any of the required character types are not found.
  • "symbols": `!@#$%^&*()_-+=[{]}\|><.,?/"';:~``
  • "uppercase": all uppercase letters
  • "lowercase": all lowercase letters
  • "letters": all letters o
  • "digits": all digits [0-9]
  • "alphanumeric": all digits and letters
  • "spaces": the character
  • * any other character you want represented with a string
    • "f29c" would be valid if it contains the characters f, 2, 9, and c
• validChars: Will return error if any characters other than the ones specified are found.
  • The list of characters if the same as the ones for mustContain
• min: the minimum length of the string
• max: the maximum length of the string
• regexp: a regular expression to test the value

createNumberValidator requirements can have the following properties:

• min: minimum value
• max: maximum value

createOneOfValidator requirements can have the following properties:

• options: array of valid values

Then, you simply pass a string to validate. It will return an array of errors (empty array if no errors).

const passwordValidator = createStringValidator({
  mustContain: ["symbols", "uppercase", "lowercase", "digits"],
  validChars: ["symbols", "alphanumeric"],
  min: 8,
  max: 45,
})

passwordValidator("Password#1805") // => [], empty array, there were no errors

passwordValidator("password#1805") // => [Error: Must contain "uppercase"] one of the requirements was "uppercase"

createNumberValidator works the same way:

const ageValidator = createNumberValidator({
  min: 18,
  max: 80,
})

// Number validators also except strings which can be converted to numbers
passwordValidator("19") // => [], empty array, there were no errors.

passwordValidator(3) // => [Error: Must be greater than or equal to 3.]

createOneOfValidator verifies the value is in the list given in options:

const fruitValidator = createOneOfValidator({options: ["apples", "oranges", "bananas"]})

fruitValidator("oranges") // => [], empty array, there were no errors.
fruitValidator("peanuts") // => [Error: "Must be apples, oranges, or bananas."]

Preset Validators

validators also comes with some preset validators. Please open an issue/pr if there are more that you need.

export const nameValidator = createStringValidator({
  min: 1,
  max: 40,
  validChars: ["letters", "., "],
})
export const ageValidator = createNumberValidator({
  min: 0,
  max: 120,
})
export const usernameValidator = createStringValidator({
  min: 3,
  max: 40,
  validChars: ["letters", "digits", "_-"]
})
export const phoneValidator = createStringValidator({
  min: 10,
  max: 10,
  validChars: ["digits"],
})
export const passwordValidator = createStringValidator({
  mustContain: ["digits", "lowercase", "uppercase", "symbols"],
  min: 8,
  max: 100,
})
export const emailValidator = createStringValidator({
  regexp: "^(([^<>()[\\]\\\\.,;:\\s@\"]+(\\.[^<>()[\\]\\\\.,;:\\s@\"]+)*)|(\".+\"))@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}])|(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,}))$",
})
export const einValidator = createStringValidator({
  regexp: "^[1-9]\\d?-\\d{7}$",
})

// sets the maximum dob as the current time, in case the subject were just born.
export const dobValidator = () => {
  const min = new Date(1900, 1, 0)
  return date => {
    if (!(date instanceof Date)) {
      try {
        date = new Date(date)
      } catch (e) {
        return [new Error(`Could not convert ${date} into a date`)]
      }
    }
    if (date < min) {
      return [new Error("Date of birth cannot be before January 1, 1900")]
    }
    if (date > new Date) {
      return [new Error("Date of birth cannot be in the future.")]
    }
    return []
  }
}

Installation

Yarn: yarn add validators

Npm: npm i validators

Dependencies

None