Handling Async Errors
Like many modern languages, JavaScript allows you to throw exceptions and catch them in a try/catch block. If uncaught, most environments will give you a helpful stack trace. For example, this code will throw an exception because ’{’ is invalid JSON:
| EventModel/stackTrace.js | |
| | function JSONToObject(jsonStr) { |
| | return JSON.parse(jsonStr); |
| | } |
| | var obj = JSONToObject('{'); |
| <= | SyntaxError: Unexpected end of input |
| | at Object.parse (native) |
| | at JSONToObject (/AsyncJS/stackTrace.js:2:15) |
| | at Object.<anonymous> (/AsyncJS/stackTrace.js:4:11) |
The stack trace tells us not only where the error was thrown from but also where the original mistake was made: line 4. Unfortunately, tracking down the causes of async errors isn’t ...
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