[tbot] [Discussion] Calling tbot from within the source directory

Thu Nov 29 09:01:34 UTC 2018

Hi Stefano, Claudius,

On Thu, 2018-11-29 at 09:32 +0100, Stefano Babic wrote:
> Hi Claudius,
> 
> On 29/11/18 08:15, Claudius Heine wrote:
> > Hi Harald,
> > 
> > Quoting Harald Seiler (2018-11-28 17:40:09)
> > > Hi Claudius,
> > > 
> > > On Wed, 2018-11-28 at 15:40 +0100, Harald Seiler wrote:
> > > > Hello Claudius,
> > > > 
> > > > On Wed, 2018-11-28 at 15:22 +0100, Claudius Heine wrote:
> > > > > Hi,
> > > > 
> > > > [...]
> > > > > 
> > > > > That is a bit tiresome. A `-C` parameter like git(1) has, would solve
> > > > > it, but I think accessing the source code via the cwd in the testcases
> > > > > as a fallback would be nice.
> > > > > 
> > > > > I might just be my different understanding of things. I like to be in
> > > > > the directory of the stuff that should be tested, not where the
> > > > > testcases are located. It also makes sense for me if multiple source
> > > > > directories need to be "tested" on the same hw.
> > > > > 
> > > > > What do you think about this?
> > > > 
> > > > Hmm, I never thought about running tbot from outside the "tbot-config"
> > > > directory.  If you feel like this is needed for your workflow to be
> > > > ergonomic, adding a -C parameter is definitely a good idea.  In terms
> > > > of implementation, I'd suggest simply changing the working directory
> > > > very early on in main if the -C parameter is present.
> > > 
> > > I pushed a commit[1] implementing -C onto the development branch.  Please
> > > try it out and tell me if it works as you need it to.  (Completions
> > > should work as well! :)
> > 
> > Thx a lot for the fast response. I wasn't expecting to have some code
> > that fast.
> > 
> > My only issue with this the `-C` solution is that it would be nice to be
> > able to use the current working directory to refer to the code you want
> > to test in the testcases.
> 
> I am quite missing the point. Do you want to know in your test case
> where the testcase file is stored ? Why ?
> 
> I think it is nice that testcase are simply stored and tbot recursive
> scans for testcase and we do not need to know where they are, simple we
> can use "import <testcase>".

I am not sure what you are trying to say here.  tbot does nothing special
with the `sys.path` in python, import can only find modules that are either
in the default path or in the testcase's directory.  You can not cross-reference
testcases from somewhere else in tbot's search path.
    In fact, tbot's search path only exists for discovering testcases that
should be callable from the commandline.

In other words:  A testcase file *has to* load properly when you do

	python3 /path/to/testcases.py

> > Otherwise you will have to put the path to the
> > code inside the testcase and that makes sharing most testcases pretty
> > much impossible.
> > 
> > Or do you have another solution, that I am not aware of for this?
> > 
> > Setting environment variables for that is also a bit stupid and using an
> > additional parameter is also overkill. Imagine that:
> > 
> >     tbot -C /path/to/tbot-privat -l labs/my-lab.py -b boards/my-board \
> >       -S "$(pwd)" my_test_case
> > 
> 
> But if you need the current directory, can we add it as attribute for
> the lab ? When tbot starts, set this attribute and you can access it in
> your test case.

This is already possible by defining a lab that is a `LocalLabHost`[1]
and defining the workdir[2] for it.

[1]: https://rahix.de/tbot/module-linux.html#tbot.machine.linux.lab.LocalLabHost
[2]: https://rahix.de/tbot/module-linux.html#tbot.machine.linux.lab.LocalLabHost.workdir

> > With `-S` as taking the path the the sources. Not as bad as the first
> > example, but still a bit overcomplicated IMO.
> > 
> > Otherwise if `-C` would work as a `change tbot configuration directory`,
> 
> I supposed this is not the case - does tbot change directory ? I thought
> -C adds the new directory to the search path.

-C changes the working directory of tbot, similar to how it works in tar or git

> > then you could use the current working directory in your testcases, so
> > you would not need an additional parameter or environment variable to
> > point the the source-tree if you want to avoid having the path to it
> > inside the testcases.
> > 
> > I hope I made myself understandable, but I basically I would like to
> > kill multiple birds with one stone:
> > 
> >  1. Make calling tbot from outside the tbot configuration directory
> >  easier.
> >  2. Make it possible to use cwd inside testcases to point to the
> >  source-tree -> make it easier to reuse/share testcases because they
> >  would not need to contain the path to the source tree anymore.
> 
> I can just imagine that you need, but if you could draft a simple real
> testcase here, it is easier to understand the reasons.

I think I can see what Claudius is on about here.  The thing is, you
shouldn't use `cwd` in your testcases, because it doesn't honor the specified
lab.  Instead you should use `lh.workdir`, which is a proper tbot path
and it's value should be defined in the lab-config.

> >  3. Do this without need of any tbot configuration files or environment
> >  variables or additional parameters.
> > 
> > But of course this would change how tbot is used. Instead of always
> > having the cwd inside the tbot configuration directory you would call
> > tbot from the source-tree. IMO it makes more sense to call tbot from the
> > source-tree than from the tbot configuration, since the primary work
> > should be done while in the source-tree. But to discuss that I started
> > this thread.
> 
> Regards,
> Stefano
> 
> > 
> > Cheers,
> > Claudius
> > 
> > 
> > > 
> > > [1]: https://github.com/Rahix/tbot/commit/a2afa7c641f87c9cf4de6616a6136ca16a4650d3
> > 
> 

-- 
Harald

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-62  Fax: +49-8142-66989-80   Email: hws at denx.de