How to throw "expressive" / console friendly exceptions in JavaScript?

Question

JavaScript noob here... I'm exploring various options for throwing exceptions.

Throwing a string / primitive value

This seems to be bad practice for several reasons (catching, stacktrace, ...)

Using Error

throw new Error("bad times")

This seems to be a common approach, but I'm not a big fan because I can't easily add extra information. I can't for example do

throw new Error("bad times", { reason: strangeObject })

I could JSON.stringify the extra information, but I like when I can expand / collapse the object in the console.

From what I can tell I won't get any farther with custom exceptions / Error-subclasses.

Throwing { msg: "bad times", reason: strangeObject }

This allows me to expand / collapse strangeObject nicely in the console. For exceptions throughout my application to be consistent, I'd need to repeat the msg: part everywhere, which I'm not a fan of.

I ended up going for the last approach, just to find out that the ESLinter complains about this approach:

Expected an error object to be thrown no-throw-literal

So, my question is basically: Can I use Error (or custom Error subclasses) in a console-friendly way, i.e. support expand/collapse?

Answer 1

I've settled for a custom exception and a window.onerror handler:

class MyAppError extends Error {
  constructor(msg, details) {
    super(msg)
    this.details = details
  }
}

window.onerror = function(message, source, lineno, colno, error) {
    if (error instanceof MyAppError) {
        console.error(message, error.details)
        return true
    }
    return false
}

function throwSomething() {
    throw new MyAppError("I made a mess", {
        someDetail: "a value",
        otherStuff: "another value"
    });
}

console.log("Hello World");
throwSomething();

(JSFiddle)

Result looks like this in Firefox and Chrome, which I'm quite happy with.