Final improvements to make tests pass on GitHub CI

[cthoyt]

This is the last PR that finally makes the unit tests work. This PR also adds several other notes to help future contributors understand the workflow, and get it running locally.

Details on an issue we solved during this PR related to SOURCE_DATE_EPOCH

The expected-draft/paper.tex which outputs the current year. This gets there because of the following code:

1. inara/data/templates/default.latex

   Line 155 in c430b5b

   \fancyfoot[L]{\parbox[t]{0.98\headwidth}{\footnotesize{\sffamily $self-citation$}.}}

2. self-citations is added in

   inara/data/filters/self-citation.lua

   Line 33 in c430b5b

   ['date-parts'] = {{meta.published_parts.year}}

3. which gets set in

   inara/data/filters/draft.lua

   Line 8 in c430b5b

   meta.published_parts = os.date('*t')

4. which comes from

   inara/data/filters/time.lua

   Line 28 in c430b5b

   local epoch = os.getenv 'SOURCE_DATE_EPOCH'

5. which in theory, is modulated by setting the SOURCE_DATE_EPOCH in

   inara/Makefile

   Lines 97 to 100 in c430b5b

   	INARA_TEST_CMD = docker run --rm \
   	--user $(shell id -u):$(shell id -g) \
   	--env SOURCE_DATE_EPOCH=1234567890 \
   	-v $${PWD}:/data $(IMAGE)

I think it's probably a fair compromise to remind ourselves once per year to update this rather than hacking more conditionals in there (at least on this pass)

[tarleb]

Can we set SOURCE_DATE_EPOCH somewhere? That should make Inara use the given time instead of the current year.

[cthoyt]

Thanks for the idea. In theory, it's set here:

inara/Makefile

Lines 97 to 100 in c430b5b

	INARA_TEST_CMD = docker run --rm \
	--user $(shell id -u):$(shell id -g) \
	--env SOURCE_DATE_EPOCH=1234567890 \
	-v $${PWD}:/data $(IMAGE)

which should get propagated through, but I'm not sure it's working correctly

[cthoyt]

@tarleb is the solution to change draft.lua to also look up the source date epoch? it doesn't seem like it reaches anywhere to check that as is

function Meta (meta)
  if meta.draft and meta.draft ~= '' then
    local epoch = os.getenv 'SOURCE_DATE_EPOCH'
      and os.time { year = 1970, month = 1, day = 1, hour = 0, min = 0,
                  sec = tonumber(os.getenv 'SOURCE_DATE_EPOCH') }
      or os.time()
    meta.article.doi = '10.xxxxxx/draft'
    meta.article.issue = '¿ISSUE?'
    meta.article.volume = '¿VOL?'
    meta.published = 'unpublished'
    meta.published_parts = os.date('*t', epoch)
    return meta
  end
end

though when I do this, the published date becomes something from 2009, is that sounding correct?

[tarleb]

👍 that looks like the right thing to do.

[cthoyt]

@tarleb okay, all done

[tarleb]

Awesome, thanks!!