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

A collection of scalar types using Joi for validation

import { GraphQLScalarType, GraphQLError, Kind } from "graphql";
import { number as yupNumber } from "yup";

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}`).negative(`Value is not a negative number: ${value}`).validateSync(value);
  const parsed = parseFloat(value);
  yupNumber().strict(true).lessThan(0, `Value is not less than 0: ${parsed}`).validateSync(parsed);
  return parsed;
};

export const NegativeFloatScalar = `scalar NegativeFloat`;
export const NegativeFloat = new GraphQLScalarType({
  name: `NegativeFloat`,
  description: `Floats that will have a value less than 0.`,

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

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

  parseLiteral(ast) {
    if (ast.kind !== Kind.FLOAT) {
      throw new GraphQLError(`Can only validate floating point numbers as negative floating point numbers but got a: ${ast.kind}`);
    }

    return validate(ast.value);
  }

});