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

Mark Hammond skippy.hammond at
Fri Aug 3 02:15:50 UTC 2018

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()



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