Firefox add-on devtools logs don't show object keys/values - firefox

Question

I'm currently developing a Firefox add-on and I noticed some logging issues in the add-on devtools (for the background script) page. Whenever I'm trying to console.log some object, I don't see any keys or values of this object in the console. There's also no way to "expand" the object like I can in the "regular" (not for an add-on) Firefox browser console.
So, if I e.g. open the add-on devtools and type console.log({ test: "test" }), I only do get "Object { }" as an output:
If I try to log an error I do get a similar result (I can e.g. still log err.message):
try {
throw new Error("");
} catch (err) {
console.log(err);
}
Since I'm currently developing the add-on locally, I'm using web-ext to launch and watch the add-on. web-ext run is essentially launching Firefox without any profile which I thought may explain the difference compared to a regular Firefox browser console.
However, even if I load the add-on in my normal Firefox profile (load temporary add-on), I do see the same behavior for any add-on devtools console.
Is there any setting in the Firefox (add-on) console (or in my preferences) that I can use to log the whole object like it does in the normal Firefox console, e.g. if I open devtools for a regular webpage:

Answer 1

It's hard to tell what's going on without seeing the relevant code for your Firefox add-on, but I have a hunch that this is happening because of reference changes in your script.
In Javascript, an object is actually a reference to a location in memory. So when you run console.log(obj), and that object is modified before you access the console, then it may show up as empty (i.e. because the value being referenced has changed).
I would make sure that the object that you are trying to log is not modified after you log it. If there are any other objects based on the one that you are trying to log, changes to them may also cause your initial object to change as well.
You can try JSON encoding to get around this for logging purposes:
console.log(JSON.parse(JSON.stringify(obj)));
If that's not the issue, then perhaps there's some weird async behavior going on. In that case, you can try logging the object at several other points in your code to see exactly where this behavior starts.