Option to run V8 test suite

[rvagg]

Requested by @bnoordhuis @ nodejs/node#2999 (comment)

Sounds like a good idea to me. Do we have enough in deps/v8 to run the tests in-tree without additional tools or do things get complicated when you need to do this?

[bnoordhuis]

Yes and no. The source tree in deps/v8 contains the test runner but there are build dependencies that must be checked out with gclient sync from depot_tools (making depot_tools a dependency as well.)

[rvagg]

a mention of depot_tools makes my eyes glaze over .. sounds like it's going to be complicated and very slow

[bnoordhuis]

Complicated maybe, but it doesn't have to be slow. gclient sync is basically git fetch plus some post-checkout actions. To keep checkout times down, keep a pristine source tree around, sync it, then cp -a it somewhere and build and test that.

[jbergstroem]

I don't think we can use v8 from deps/v8; gclient expects a proper git tree. Running this on all slaves sounds like a bit of a stretch, but even getting one vm testing (debian 8, freebsd or smartos vm's has most cpu to spare) would be pretty great.

Edit: I guess we'd have to check out the tag and then reapply our floating patches to properly test it.

[mhdawson]

+1 on the idea for me. I think @jasnell had done some initial work looking at doing this.

[jasnell]

There's a bit of work involved but I had this working in joyent/node master. I can update and get it running again. It'll just take a couple weeks given current workload

[pmq20]

If we were to land fixes about v8 this definitely is a must.

[rvagg]

right, particularly as we move into LTS-land where we're supporting old V8

[joransiu]

Pinged @jasnell yesterday, and he pointed us to his old PR nodejs/node-v0.x-archive#14185 on this topic. We're looking into reviving and flushing out some of his changes there.

/cc @exinfinitum

[exinfinitum]

@jasnell I found a way to run v8 tests in node. This was originally developed for zLinux version of node, to run tests on v8z (a port of v8 to IBM s390(x) CPUs), but should also work for v8. Checkout https://github.com/exinfinitum/node/tree/al-merge (branch "al-merge") and run the following commands:

make v8 DESTCPU=(ARCH)
make test-v8 DESTCPU=(ARCH)

where (ARCH) is your CPU architecture, e.g. x64, ia32. DESTCPU MUST be specified for this to work properly.

Can also do tests on debug build by using "make test-v8 DESTCPU=(ARCH) BUILDTYPE=Debug".

[mhdawson]

If its not too much work could you create a PR that applies to master so we could try it out there. I think it would also trim down what needs to be reviewed to the minimal set. James is on holiday this week so probably worth doing this instead of waiting to hear from him.