assertInput

Assert input is a small library to easily verify different types of user inputs. It will work on an object of data and return a rejected promise with a suiting error messages if any data is not validated. If all data is validated, it will returned a cleaned object with any superfluous fields removed.

Examples

When data isn't validated

const assertInput = require('./index');
 
const data = {
    name: 'xyz',
    age: 150
};
 
assertInput({
    name: assertInput.minMaxStringLength(4, 50),
    age: assertInput.minMax(5, 99),
}, data)
.then(insertIntoDatabase)
.catch(throwError);

Function throwError will be called with

[ "name must be a string longer than 4 characters.",
  "age must be at most 99." ]

When all data is validated

const assertInput = require('./index');
 
const data = {
    name: 'Foo Bar',
    age: 42,
    someOtherField: 'some other data'
};
 
assertInput({
    name: assertInput.minMaxStringLength(4, 50),
    age: assertInput.minMax(5, 99),
}, data)
.then(insertIntoDatabase)
.catch(throwError)

Function insertIntoDatabase will be called with

{
    "name": "Foo Bar",
    "age": 42
}

Validators

Numbers

• isNumber
• minNumber(min)
• maxNumber(max)
• minMaxNumber(min, max)

Strings

• isString
• minStringLength(min)
• maxStringLength(max)
• minMaxStringLength(min, max)

More validators coming soon

Custom validators

You can create your own validators and use them in combinations with the already existing ones.

const assertInput = require('./index');
 
// Create the validator
let hexColorValidator = {
    validate: (data) => /^#?([a-f0-9]{6}|[a-f0-9]{3})$/.test(data),
    failText: `must be a hex color.`
};
// Combine it with isString to first verify that the data is a string
hexColorValidator = [assertInput.isString, hexColorValidator];
 
assertInput({
    color: hexColorValidator,
}, data)
.then(insertIntoDatabase)
.catch(throwError);