Using JavaScript's Error Object for Stack Tracing

When writing a function in JavaScript that has a conditional with a failure condition, one can utilize the Error object which has the advantage of collecting a stack trace whenever a failure condition is met.

The message property of this global object allows for creation of a custom error message in a simple manner:

let t = true, f = false

function assert(condition, message) {
    if (!condition) {
        throw new Error(message || "Assertion failed")
    }
}

assert(f)

In VSCode (with Quokka):

Assertion failed 
  at assert quokka.js:5:9
  at quokka.js:9:1

In PlayCode:

Error: Assertion failed
[email protected]://preview-empty_javascript.playcode.io/ line 18 > injectedScript:46:11
@https://preview-empty_javascript.playcode.io/ line 18 > injectedScript:50:7
[email protected]://preview-empty_javascript.playcode.io/ line 6 > injectedScript:18:5449

Getting a stack trace for custom logic is really useful when doing testing and debugging.

#TIL #TheMoreYouKnow

11 Dec 2022

Using JavaScript's Error Object for Stack Tracing

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