co-validate v0.1.0

A library for validating objects.

• It has no dependencies (just dev dependencies).
• Validates also deeply nested objects and arrays.
• configurable validation messages
• configurable validation options
• Writen in TypeScript (Types are included)

Installation

npm install co-validate --save

Usage

In the following example, you can see a basic example for a login data validation. Create a Schema instance with the object description.

JavaScript (Validate)

const coValidate = require('co-validate');

const objectDescription =  {
  username: {
    type: 'string', // username needs to be a string
    min: 4, // username can't be shorter than 4 characters
    max: 64, // username can't be longer than 64 characters
    required: true // username need to be set
  },
  password: {
    regExp: /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/, // this regExp will be used for testing
    required: true // password need to be set
  }
};
const schema = new coValidate.Schema(objectDescription);

const objectToValidate1 = {
  username: 'myUsername',
  password: 'mySecretPassword1'
}
schema.validate(objectToValidate1);
if (schema.validationErrorMessages.length > 0) {
  // will not get called
} else {
  // will get called
  // everything is fine
}

const objectToValidate2 = {
  username: 'myUsername',
  password: 'mySecretPassword'
}
schema.validate(objectToValidate2);
if (schema.validationErrorMessages.length > 0) {
  // will get called
  // [
  // {
  //    fullPath: ['password']
  //    message: 'something went wrong' // this is the fallback message
  // }
  // ]
} else {
  // will not get called
}

TypeScript (Validate)

import { Schema } from 'co-validate';

const objectDescription : ISchemaConfigEntry =  {
  username: {
    type: 'string', // username needs to be a string
    min: 4, // username can't be shorter than 4 characters
    max: 64, // username can't be longer than 64 characters
    required: true // username need to be set
  },
  password: {
    regExp: /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/, // this regExp will be used for testing
    required: true // password need to be set
  }
};
const schema = new Schema(objectDescription);

const objectToValidate1 = {
  username: 'myUsername',
  password: 'mySecretPassword1'
}
schema.validate(objectToValidate1);
if (schema.validationErrorMessages.length > 0) {
  // will not get called
} else {
  // will get called
  // everything is fine
}

const objectToValidate2 = {
  username: 'myUsername',
  password: 'mySecretPassword'
}
schema.validate(objectToValidate2);
if (schema.validationErrorMessages.length > 0) {
  // will get called
  // [
  // {
  //    fullPath: ['password']
  //    message: 'something went wrong' // this is the fallback message
  // }
  // ]
} else {
  // will not get called
}

JavaScript (Validate & Parse)

const coValidate = require('co-validate');

const objectDescription =  {
  username: {
    type: 'string', // username needs to be a string
    min: 4, // username can't be shorter than 4 characters
    max: 64, // username can't be longer than 64 characters
    required: true // username need to be set
  },
  password: {
    regExp: /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/, // this regExp will be used for testing
    required: true // password need to be set
  }
};
const schema = new coValidate.Schema(objectDescription);

const objectToValidate1 = {
  username: 'myUsername',
  password: 'mySecretPassword1',
  notneeded: 'should not be here' // a property which shouldn't be there
}
schema.validate(objectToValidate1).parse();
if (schema.validationErrorMessages.length > 0) {
  // will not get called
} else {
  // will get called
  // everything is fine
  // from now on use schema.parsedVariable, because it only contains the specified properties and removes everything else.
  // schema.parsedVariable = {
  //  username: 'myUsername',
  //  password: 'mySecretPassword1'
  // }
}
...

TypeScript (Validate & Parse)

import { Schema } from 'co-validate';

const objectDescription : ISchemaConfigEntry =  { // using the ISchemaConfigEntry interface will help you to define the Schema
  username: {
    type: 'string', // username needs to be a string
    min: 4, // username can't be shorter than 4 characters
    max: 64, // username can't be longer than 64 characters
    required: true // username need to be set
  },
  password: {
    regExp: /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/, // this regExp will be used for testing
    required: true // password need to be set
  }
};
const schema = new Schema(objectDescription);

const objectToValidate1 = {
  username: 'myUsername',
  password: 'mySecretPassword1',
  notneeded: 'should not be here' // a property which shouldn't be there
}
schema.validate(objectToValidate1).parse();
if (schema.validationErrorMessages.length > 0) {
  // will not get called
} else {
  // will get called
  // everything is fine
  // from now on use schema.parsedVariable, because it only contains the specified properties and removes everything else.
  // schema.parsedVariable = {
  //  username: 'myUsername',
  //  password: 'mySecretPassword1'
  // }
}

Schema Properties

Validation Messsages

All the API properties can be objects with messages.

...
'type' : {
  value: 'string',
  message: 'value needs to be a string'
}
...

Multi Language Validation Messsages

It's possible to define different error messages for different purposes. This behaviour could be used for different validation message languages, but it could be also used for different messages in dev and prod enviroment etc.

...
const objectDescription =  {
  username: {
    type : {
      value: 'string', // username needs to be a string
      message: {
        de: 'german error message',
        en: 'english error message'
      }
    },
    min: 4, // username can't be shorter than 4 characters
    max: 64, // username can't be longer than 64 characters
    required: true // username need to be set
  },
  password: {
    regExp: /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[0-9a-zA-Z]{8,}$/ // this regExp will be used for testing
    required: true // password need to be set
  }
};
// would from now on return german error messages
const options = {
  countryCode: 'de'
}
const schema = new Schema(objectDescription, options);
...

Validation Messages

All validation messages will get stored in an Array of Objects. An validation message will get stored in an object. This object has 2 properties 'fullPath' and 'message'. In the fullPath property you will get the fullPath to the value in form of an string array. The message property is for storing the conresponding error message.

const objectToValidate = {
  users: [
    {
      id: 1,
      role: 'admin'
    },
    {
      id: 2,
      role: true // Entry in validationErrorMessages would show that this is the problem
    },
    {
      id: 3,
      role: 'admin'
    },
  ]
};

const validationErrorMessages = [
{
  fullPath: ['users' 1, 'role'],
  message: 'role should be a string'
};
]