Error Unstack

A nice display of the error stack in your CLI

Installation • Usage • Documentation • License • Contact • Support

Description

Error chains with cause look cool on paper, but unpacking them in the console is a nightmare. errorUnstack takes your nested errors and transforms them into a formatted, readable, and structured display. File positions, clear messages, attached data, colors... everything you need to debug without the headache.

Installation

npm i @cafeine-software/errorunstack

Usage

Minimalist

import { displayErrorStack } from '@cafeine-software/errorunstack';

function bar() {
    throw new Error("Bar function failed");
}

function foo() {
    try {
        bar()
    }
    catch (err) {
        throw new Error("Bar call failed", { cause: err });
    }
}

try {
    foo();
}
catch (err) {
    displayErrorStack(err, "Error in main execution");
}

Custom data

You can add custom data for debug purpose by filling the data argument of the Error object.

import { displayErrorStack } from '@cafeine-software/errorunstack';

function bar() {throw new Error("Bar function failed");}

function foo(level) {

    try { bar();}
    catch (err) {
        const error = new Error("Bar call failed", { cause: err });
        error.data = {
            level: level,
            timestamp: [43,56,"toto","titi"],
            object: {nested: {value: 123}}
        }
        throw error;
    }

}

try {foo(42);}
catch (error) {
    displayErrorStack(error, "Error in main execution");
}

Special key : method

You can specify a method key in you custom data object, it will display beside code coordinate (line:col) the method name

function bar() {

    const error = new Error("Bar function failed");
    error.data = {
        method: "bar"
    }
    throw error;
}

function foo(level) {

    try { bar(); }
    catch (err) {
        const error = new Error("Bar call failed", { cause: err });
        error.data = {
            level: level,
            timestamp: [43, 56, "toto", "titi"],
            object: { nested: { value: 123 } },
            method: "foo"
        }
        throw error;
    }

}

try { foo(42); }
catch (error) {
    displayErrorStack(error, "Error in main execution");
}

Documentation

The package export two methods extractErrorChain and displayErrorStack

extractErrorChain(error)

Extract the error chain from an Error object

Parameters

Parameter	Type	Default	Description
error	Error	-	The error (contaning causes stack)

Returns

Array<ErrorEntry> - An array containing object describing each error

displayErrorStack

Display a formatted error stack in the console

Parameters

Parameter	Type	Default	Description
error	Error	-	The error (contaning causes stack)
title	String	An error occurred	Title to display above the error stack

Returns

Void

Types

ErrorEntry

Parameter	Type	Default	Description
message	String	-	The error message
file	String	-	The file where the error occurred
line	Number	-	The line where the error occurred
col	Number	-	The col where the error occurred
data	Object	-	Custom data added to the error

License

Contact

Developed by Quentin Lamamy.

• Email: contact@quentin-lamamy.fr
• GitHub: github.com/quentin-lamamy
• Cafeine Github: github.com/Cafeine-Software

Support