improve generator tests

[lubegasimon]

This PR is intended to fix #651.

Todo:

• Currently (in this PR), to generate the output files, one has to run the test command three times. The first one for generating link.dune.inc.gen and promoting it to link.dune.inc, the second for generating <html&latex&man>.dune.inc.gen, and promoting them to <html&latex&man>.dune.inc, and the third for generating and promoting output files (latex, html, and man-pages). In that sense, it makes more sense to wrap the series of test command under one command

[Julow]

Looks good !

Latex tests are very noisy because of a debug print that should be removed:

diff --git a/src/latex/generator.ml b/src/latex/generator.ml
index 3abb962e..9626b055 100644
--- a/src/latex/generator.ml
+++ b/src/latex/generator.ml
@@ -62,7 +62,6 @@ module Link = struct
   let filename url =
     let dir = dir url in
     let file = file url in
-    Format.eprintf "dir=%a file=%s\n%!" Fpath.pp dir file;
     if file = "" then Fpath.add_ext "tex" dir
     else Fpath.(add_ext "tex" (dir / file))
 end

[Julow]

• test/generators/cases/ocamlary.mli is a copy of src/ocamlary/ocamlary.mli, I suggest making it a symlink instead (ln -sf ../../../ocamlary/ocamlary.mli test/generators/cases/ocamlary.mli)

• Bugs_pre_410 shouldn't run on OCaml < 4.10, that's what is causing the CI failures.
  It needs (enabled_if (>= %{ocaml_version} 4.10.0)) on the corresponding "alias runtest, action diff" rule (the other rules doesn't need to change).
  It's fine if this is hard-coded into Gen_backend, we might need more of these in the future:

  val case_enabled_if : Fpath.t -> sexp option

• A rebase is needed but might be annoying to do. I suggest squashing some of the commits together to avoid fixing the same conflict 14 times.

[lubegasimon]

Ready for another review

[jonludlam]

The v2 PR #697 looks much nicer, so closing this one!