@saeris/graphql-scalars/dist-src/url.js

A collection of scalar types using Joi for validation

import { GraphQLScalarType, GraphQLError, Kind } from "graphql";
import { string as yupString } from "yup";
import { parse } from "uri-js";

const validate = value => yupString().strict(true).typeError(`Value is not string: ${value}`).test(`uri`, `Value is not a valid URL: ${value}`, val => !!parse(val).scheme).validateSync(value);

export const URLScalar = `scalar URL`;
export const URL = new GraphQLScalarType({
  name: `URL`,
  description: `A field whose value conforms to the standard URL format as specified in RFC3986: https://www.ietf.org/rfc/rfc3986.txt.`,

  serialize(value) {
    return validate(value);
  },

  parseValue(value) {
    return validate(value);
  },

  parseLiteral(ast) {
    if (ast.kind !== Kind.STRING) {
      throw new GraphQLError(`Can only validate strings as URLs but got a: ${ast.kind}`);
    }

    return validate(ast.value);
  }

});