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

A collection of scalar types using Joi for validation

import { GraphQLScalarType, GraphQLError, Kind } from "graphql";
import { number as yupNumber } from "yup";
export const rangeFactory = ({
  name,
  start,
  end,
  float = false
}) => {
  const validate = value => {
    yupNumber().typeError(`Value is not a number: ${value}`).notOneOf([Infinity, -Infinity], `Value is not a finite number: ${value}`).required(`Value is not a number: ${value}`).min(0, `Value is not a positive number: ${value}`).validateSync(value);

    if (!float) {
      yupNumber().integer(`Value is not an integer: ${value}`).test(`unsafeInt`, `Value is not a number: ${value}`, val => Number.isSafeInteger(val)).validateSync(value);
    }

    const parsed = float ? parseFloat(value) : parseInt(value, 10);
    yupNumber().strict(true).min(start, `Value is less than limit: ${start}: ${parsed}`).max(end, `Value is greater than limit: ${end}: ${parsed}`).validateSync(parsed);
    return parsed;
  };

  return {
    scalar: `scalar ${name}`,
    resolver: new GraphQLScalarType({
      name,
      description: `A${float ? ` Float` : `n Integer`} with a value between ${start} and ${end} (inclusive).`,

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

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

      parseLiteral(ast) {
        if (ast.kind !== (float ? Kind.FLOAT : Kind.INT)) {
          throw new GraphQLError(`Can only validate ${float ? `Floats` : `Integers`} but got a: ${ast.kind}`);
        }

        return validate(ast.value);
      }

    })
  };
};