GitHub - googlemaps/js-typescript-guards: TypeScript guards for the Google Maps JavaScript API. (original) (raw)

Google Maps TypeScript Guards

Description

This package provides TypeScript guards for the Google Maps JavaScript API.

A type guard (or type predicate) is an expression that performs a runtime check that guarantees the type in some scope. Type guards are used to narrow the type of a variable or parameter.

Documentation

For the complete API check the reference documentation.

Install

Available via npm as the package @googlemaps/typescript-guards.

npm i @googlemaps/typescript-guards

Example

The following example narrows a union type google.maps.LatLng | google.maps.LatLngLiteral to google.maps.LatLngLiteral using the isLatLngLiteral guard.

import { isLatLngLiteral } from "@googlemaps/typescript-guards";

const latLng: google.maps.LatLng | google.maps.LatLngLiteral = ...;

if (isLatLngLiteral(latLng)) { lat = latLng.lat; lng = latLng.lng; } else { lat = latLng.lat(); lng = latLng.lng(); }