How can I create a javascript library (distributed as module on npm) with different implementations depending on whether the environment it gets run in (transpiled to??) has proxy support or not?
As I understand it babel doesn't (at least easily) support transpilling proxies so this isn't easily fixable just via transpilation.
You have a few options:
An example is this (which I think should be good enough) or this.
Proxy variable existsUnless you declared a variable named Proxy, I think this should be good enough.
console.log(typeof Proxy !== 'undefined')This will output a Boolean value whether Proxy is available.
Example usage of the above:
if(typeof Proxy !== 'undefined') {
// run code that uses Proxies
console.log('I can use Proxies here!')
}
else {
// run code that doesn't use Proxies
console.log('Oops! I can\'t use Proxies here!')
} NOTE: You have to use typeof to check whether the Proxy variable exists or not, as it will just return undefined instead of throwing an error.