muonsoft / validation

import (

	"errors"

	"net/url"

)

var (

	ErrUnexpectedSchema = errors.New("unexpected schema")

)

// URL is used to validate that value is a valid URL string. By default (if no schemas are passed),

// the function checks only for the http:// and https:// schemas. Use the schemas argument

// to configure the list of expected schemas. If an empty string is passed as a schema, then

// URL value may be treated as relative (without schema, e.g. "//example.com").

//

// If value is not a valid URL the function will return one of the errors:

//	• parsing error from url.Parse method if value cannot be parsed as an URL;

//	• ErrUnexpectedSchema if schema is not matching one of the listed schemas;

//	• ErrInvalid if value is not matching the regular expression.

func URL(value string, schemas ...string) error {

	if len(schemas) == 0 {

		schemas = []string{"http", "https"}

	}

	u, err := url.Parse(value)

	if err != nil {

		return err

	}

	err = validateSchema(u, schemas)

	if err != nil {

		return err

	}

	if !urlRegex.MatchString(value) {

		return ErrInvalid

	}

	return nil

}