Build JavaScript files during python package build

[stefangehn]

Make package builds via setuptools automatically trigger building of
merged & minified JS assets.

This fixes installing isso from source when using pip install as long
as both the python and node requirements are met. It also ensures that
setup.py commands like build or bdist_wheel create archives that
contain generated JS code.

[ix5]

That feels a bit too magic to me? Maybe just warn if the minified js files are not found.

[stefangehn]

I wouldn't know what part should warn about these files missing.

Since this step is required for building a working redistributable package (may it be a wheel or just a tarball) this looks like a good place to me. It also makes it obvious that you will need npm if you use pip install on the github URL instead of failing more or less silently in the browser because the required files are missing.

The idea for this was actually taken from the readthedocs sphinx theme:
https://github.com/readthedocs/sphinx_rtd_theme/blob/master/setup.py#L16

[ix5]

Again, just my personal preference. I can see that your approach would solve a lot of annoying newbie issues.

The primary reason for people to install from source is because the isso package in pypi has historically been outdated or even broken (werkzeug==1.0) for long stretches of time.

People installing directly via pip install git+https://github.com/posativ/isso would need to have node+npm installed already, which might be non-obvious. I'd also wager that these people don't really want to install all this js ecosystem stuff just to get an updated package.

My favourite way to resolve this whole issue would be to keep minified versions of the js assets in this repo, but sadly that might break the make-based change detection.

---

(I guess your approach wouldn't affect FTBFS issues since you'd invoke the make commands in the "prepare" stage anyway, and not use python to generate the minified js assets?)

[ix5]

I've created #703 to clarify more issues that might pop up when installing from source.
But I'm growing more and more partial to your approach, considering e.g. the experience of users in #656.

[jelmer]

check_call() ?

[stefangehn]

Indeed. Although subprocess.run(..., check=True) does the same I find subprocess.check_call() to be a bit more obvious and in fact know it from Python 2.7 already.

[stefangehn]

Rebased and applied the check_call() suggestion.

Sorry for the long delay, work and health kept me busy lately.

[jelmer]

Please resolve the conflict?

[ix5]

Note that packages created by python3 setup.py sdist and installed via pip will attempt to run the NpmBuildCommand.
A way to specify that the command is only to be run when installing from source is needed.

[stefangehn]

Feel free to revert, I don't need it myself and I don't intend to dive any further into the sorry state of python packaging

[jelmer]

Let's revert.