@jokio/graphql/src/modules/scalars/datetime/dateTime/index.ts

High level, pre-configured, GraphQL Server

// @flow
/**
 * Copyright (c) 2017, Dirk-Jan Rutten
 * All rights reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

import { GraphQLScalarType } from 'graphql'
import { GraphQLScalarTypeConfig } from 'graphql' // eslint-disable-line
import { Kind } from 'graphql/language'
import {
	validateDateTime,
	validateUnixTimestamp,
	validateJSDate,
	serializeDateTime,
	serializeDateTimeString,
	serializeUnixTimestamp,
	parseDateTime
} from '../utils'

/**
 * An RFC 3339 compliant date-time scalar.
 *
 * Input:
 *    This scalar takes an RFC 3339 date-time string as input and
 *    parses it to a javascript Date.
 *
 * Output:
 *    This scalar serializes javascript Dates,
 *    RFC 3339 date-time strings and unix timestamps
 *    to RFC 3339 UTC date-time strings.
 */
const config: GraphQLScalarTypeConfig<Date, string> = {
	name: 'DateTime',
	description: 'A date-time string at UTC, such as 2007-12-03T10:15:30Z, ' +
	'compliant with the `date-time` format outlined in section 5.6 of ' +
	'the RFC 3339 profile of the ISO 8601 standard for representation ' +
	'of dates and times using the Gregorian calendar.',
	serialize(value) {
		if (value instanceof Date) {
			if (validateJSDate(value)) {
				return serializeDateTime(value)
			}
			throw new TypeError('DateTime cannot represent an invalid Date instance')
		} else if (typeof value === 'string' || value instanceof String) {
			if (validateDateTime(value)) {
				return serializeDateTimeString(value)
			}
			throw new TypeError(
				`DateTime cannot represent an invalid date-time-string ${value}.`
			)
		} else if (typeof value === 'number' || value instanceof Number) {
			if (validateUnixTimestamp(value)) {
				return serializeUnixTimestamp(value)
			}
			throw new TypeError(
				'DateTime cannot represent an invalid Unix timestamp ' + value
			)
		} else {
			throw new TypeError(
				'DateTime cannot be serialized from a non string, ' +
				'non numeric or non Date type ' + JSON.stringify(value)
			)
		}
	},
	parseValue(value) {
		if (!(typeof value === 'string' || value instanceof String)) {
			throw new TypeError(
				`DateTime cannot represent non string type ${JSON.stringify(value)}`
			)
		}

		if (validateDateTime(value)) {
			return parseDateTime(value)
		}
		throw new TypeError(
			`DateTime cannot represent an invalid date-time-string ${value}.`
		)
	},
	parseLiteral(ast) {
		if (ast.kind === Kind.STRING) {
			if (validateDateTime(ast.value)) {
				return parseDateTime(ast.value)
			}
		}
		return null
	}
}

export default new GraphQLScalarType(config)