Changing `lvtext` in non-default configs does not work

[muzimuzhi]

If lvtext is only changed in a non-default config (for example, lvtext = ".tex"), then the new lvtext is never used when checking with config.

Use this repository as an example,

1. add lvtext = ".tex" to config-plain.lua and an empty test.tex to ./testfiles-plain
2. run either l3build check -q or l3build check -cconfig-plain -q and see test.tex is not checked, and the *.lvt tests in ./testfiles-plain are still being checked.

$ l3build check -q -cconfig-plain
Running checks on
  plain-pdftex (1/1)
(guessed encoding #3: ASCII = utf8)(guessed encoding #5: ASCII = utf8)(guessed encoding #6: ASCII = utf8)

The cause is, the values of lvtext and other ...ext variables are stored in and in latter uses retrieved from table test_types, which is only set once in l3build-variables.lua, and not updated after a non-default config is loaded by l3build.lua (see line 227 in l3build.lua snippet below, dofile(config)).

l3build/l3build-variables.lua

Lines 222 to 236 in f757458

	test_types = test_types or { }
	test_types.log = test_types.log or {
	test = lvtext,
	generated = logext,
	reference = tlgext,
	expectation = lveext,
	compare = compare_tlg,
	rewrite = rewrite_log,
	}
	test_types.pdf = test_types.pdf or {
	test = pvtext,
	generated = pdfext,
	reference = tpfext,
	rewrite = rewrite_pdf,
	}

l3build/l3build.lua

Lines 225 to 229 in f757458

	if fileexists(config) then
	local savedtestfiledir = testfiledir
	dofile(config)
	-- Sanity check for non-default config
	check_engines(configname .. ".lua")

[muzimuzhi]

If lvtext is only changed in a non-default config (for example, lvtext = ".tex"), then the new lvtext is never used when checking with config.

Just in case, is this valid usage?

I switched to this kind of setting in muzimuzhi/latex-zutil@5290480. The lvtext = ".tex" set for a specific config was inherited from https://github.com/lvjr/tabularray, and I decided to use the default .lvt extension in new set(s) of tests and keep old settings for inherited set of tests.

[josephwright]

Ah, that's a bit tricky - it used to work before we split the different types of test; I wonder if we should make it work again or change the docs here?