Should we make content console messages print to stdout when browser.dom.window.dump.enabled is true?

Brian Grinstead bgrinstead at
Fri Aug 3 14:40:05 UTC 2018

Huh - must have missed that during error console removal. I don’t think the pref name fits close enough with this proposed behavior to reuse it, so I’ll file a bug to remove it.


> On Aug 2, 2018, at 7:25 PM, Mike Hommey <mh at> wrote:
>> On Fri, Aug 03, 2018 at 12:15:50PM +1000, Mark Hammond wrote:
>>> On 3/08/2018 5:16 am, Brian Grinstead wrote:
>>> In Bug 1439686 we started printing chrome console messages to stdout. At that time we restricted it to chrome callers to avoid extra noise in stdout during local builds - especially since filtering out content messages is a much-requested feature for the Browser Console (Bug 1260877).
>>> Interestingly, a page can already get text out to stdout if browser.dom.window.dump.enabled is true using `window.dump`. But the output isn't great when dealing with objects, and it requires the page to change its code.
>>> We got a request to enable this for console.log in Bug 1480544 - I'm curious if people have opinions on if/how this should be exposed. Should the output be controlled based on the browser.dom.window.dump.enabled pref? Should we have a second pref controlling itf? Something else?
>> This is tricky. I use dump() more than I'd care to admit - it works well in
>> content code because you almost never see dump() used in real sites (does
>> Chrome even support it?), so there's not a huge amount of "spam" in the
>> terminal. Having dump() output from *both* chrome and content can be very
>> helpful.
>> If we also wrote console.log() from content to the terminal, I fear we would
>> then end up in a situation where content spams the terminal, with the only
>> mitigation being to flip browser.dom.window.dump.enabled to false - but that
>> means we also lose dump() output, throwing the baby out with the bathwater.
>> So my vote would be:
>> * Leave dump alone - it's basically a firefox-specific easter-egg and no one
>> seems to mind that content *could* spam the terminal because it almost never
>> does. (I know this wasn't proposed, but it's worth clarifying imo)
>> * A new pref that would allow content console.* output to be written to this
>> terminal. I'd be fine with this defaulting to true wherever
>> browser.dom.window.dump.enabled does.
>> Having "dump" in the name of this pref wouldn't be a good option, because
>> IMO, it should *not* affect the behaviour of dump()
> There's javascript.options.showInConsole, too, but I'm not sure it does
> anything these days, despite being defined in all.js, firefox.js and
> other places, it seems it was made a no-op by the error console removal
> in bug 1278368.
> Mike
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