715242 - Add build-time syntax checking for JS files in the Fennec build

Status: RESOLVED WORKSFORME

(Firefox Build System :: General, defect)

Description

[Kartikaya Gupta (email:[e-mail])]

Often I make a change to browser.js only to find out I had a typo somewhere when I run it. We should add some sort of JS-lint syntax checker into the build to catch dumb syntax errors faster.

Comment 1

[Doug Turner (:dougt)]

any idea what we can do here Kats/Kyle?

Comment 2

[Kartikaya Gupta (email:[e-mail])]

I looked briefly at JSlint and their ilk but it seems they don't like the "let" keyword we use all over the place. Since that's mozilla-specific it makes sense to use SpiderMonkey to check syntax instead of some other tool. Unfortunately the latest version of SpiderMonkey (that I built from trunk) no longer has the -C option (as seen at https://developer.mozilla.org/En/SpiderMonkey/Introduction_to_the_JavaScript_shell) to compile a JS file without running it. Maybe we could use an older version of SpiderMonkey that still has the option?

Comment 3

[(not currently active) Ted Mielczarek]

Or we could just add the option back in a more useful way, or something.

The downside is that the JS shell you'd build as part of an Android build is for ARM...

Comment 4

[Kartikaya Gupta (email:[e-mail])]

True. Does rhino support mozilla-isms? That could run on any/most platforms, and presumably could do syntax checking.

Comment 5

[Blake Kaplan (:mrbkap) (inactive)]

For what it's worth, in bug 715498, I just brought back support for 'js -c' for "compile only".

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Great, thanks! I looked at rhino and it doesn't appear to support "let" or have options for syntax checking only. js -c seems to work well, we just need to hook it into the build system.

Comment 7

[Kartikaya Gupta (email:[e-mail])]

Seems like |mach eslint| can be (ab)used to do this so I'm going to close out this bug.