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

A collection of scalar types using Joi for validation

import { GraphQLScalarType, GraphQLError, Kind } from "graphql";
import { string as yupString } from "yup";
export const regularExpressionFactory = ({
  name,
  regex
}) => {
  const validate = value => yupString().strict(true).typeError(`Value is not string: ${value}`).matches(new RegExp(regex), `Value does not match the regular expression ${regex}: ${value}`).validateSync(value);

  return {
    scalar: `scalar ${name}`,
    resolver: new GraphQLScalarType({
      name,
      description: `A field whose value matches the provided regular expression ${regex}.`,

      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 regular expressions but got a: ${ast.kind}`);
        }

        return validate(ast.value);
      }

    })
  };
};