Error handling

Source lib

Basic

Error handling using try-catch syntax is pretty weird, because it adds an extra block nesting usually makes you to use let instead of const keyword and spend more lines of code, than it needed

There is a simple util to avoid such cons:

const [result, error] = cope(() => JSON.parse(UNRELIABLE_JSON_STRING))

It's a lot simpler, than:

let result: SomeData | undefined
try { 
  result = JSON.parse(UNRELIABLE_JSON_STRING) 
} 
catch (e) { /* ... */ } 

The util inspired by error handling in Golang, and also makes code to be more obvious in complex error handling

const [response, fetchError] = await cope(() => api.loadData())
if (fetchError)
  alert('server cant be reached or request is broken')

const [data, parsingError] = await cope(() => response.json())
if (parsingError)
  alert('failed to parse received data')

Default value

You can use native destructuring default syntax

const [result = 'default value', syncParseErr] = cope(/* ... */)
result // is always defined

Force execution

You can use this util just to ignore fails of execution:

// Some preparing execution
cope(() => window.querySelector('#dynamic-element').scrollTo(123, 0))
// Some guaranteed executions