Avoid reassigning exceptions in catch clauses

Docs > Code Analysis > Static Analysis Rules > Avoid reassigning exceptions in catch clauses

This page is not yet available in Spanish. We are working on its translation.
If you have any questions or feedback about our current translation project, feel free to reach out to us!

Metadata

ID: typescript-best-practices/no-ex-assign

Language: TypeScript

Severity: Error

Category: Best Practices

Description

Catching an exception and assigning a different value to the error parameter will overwrite the reference to the original error data, which will be lost since there is no arguments object in a catch clause.

Non-Compliant Code Examples

try { } catch (e) { e = 10; }
try { } catch (ex) { ex = 10; }
try { } catch (ex) { [ex] = []; }
try { } catch (ex) { ({x: ex = 0} = {}); }
try { } catch ({message}) { message = 10; }

Compliant Code Examples

try { } catch (e) { three = 2 + 1; }
try { } catch ({e}) { this.something = 2; }
function foo() { try { } catch (e) { return false; } }