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

A collection of scalar types using Joi for validation

import { GraphQLScalarType, GraphQLError, Kind } from "graphql";
import { string as yupString } from "yup";

const validate = value => yupString().strict(true).typeError(`Value is not string: ${value}`).matches(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3}|[A-Fa-f0-9]{8})$/i, `Value is not a valid HexColorCode: ${value}`).validateSync(value);

export const HexColorCodeScalar = `scalar HexColorCode`;
export const HexColorCode = new GraphQLScalarType({
  name: `HexColorCode`,
  description: `A field whose value is a hex color code: https://en.wikipedia.org/wiki/Web_colors.`,

  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 hex color codes but got a: ${ast.kind}`);
    }

    return validate(ast.value);
  }

});