JavaScript-Problems-and-Solution/async&await.html at master · evitajain15/JavaScript-Problems-and-Solution · GitHub

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<!DOCTYPE html>
<html>
<head>
	<title>Promises</title>
	<style>

	</style>
	</head>
<body>

	<script>
		class HttpError extends Error{
			constructor(response){
				super(`${response.status} for ${response.url}`);
				this.name = 'HttpError';
				this.response = response;
			}
		}

		async function loadJson(url){
			let response = await fetch(url);
			if (response.status == 200){
				return response.json();
			} else{
				throw new HttpError(response);
			}
		}

		async function demoGithubUser(){
			let user;

			while(true){
				let name = prompt("Enter a name?", "iliakan");

				try{
					user = await loadJson(`https://api.github.com/users/${name}`);
					break;
				}
				catch(err){
					if(err instanceof HttpError && err.response.status == 404){
						alert("No such user, please reenter.");
					} else{
						throw err;
					}
				}
			}

			alert(`Full name: ${user.name}.`);
			return user;
		}

		demoGithubUser();
	</script>
</body>
</html>