test(package-deps): snapshot template-added library requirements

test/blackbox-tests/test-cases/package-materialization/dune

@@ -3,5 +3,6 @@
   installed-package
   no-transitive-through-targets
   ocamlfind
+  template-dependencies
   virtual-without-default)
  (deps %{bin:ocamlfind}))

test/blackbox-tests/test-cases/package-materialization/template-dependencies.t

@@ -0,0 +1,108 @@
+A META file template may add a library requirement that is absent from Dune's
+internal library graph. The scoped layout must not emit that requirement
+without also handling its dependency.
+
+  $ make_dune_project 3.24
+  $ cat >>dune-project <<EOF
+  > (package (name template-root))
+  > (package (name template-middle))
+  > (package (name template-extra))
+  > (package (name template-explicit))
+  > EOF
+
+  $ mkdir root middle extra unrelated explicit
+  $ cat >root/dune <<'EOF'
+  > (library
+  >  (name root)
+  >  (public_name template-root)
+  >  (libraries template-middle.selected))
+  > EOF
+  $ echo 'let value = ()' >root/root.ml
+
+  $ cat >middle/dune <<'EOF'
+  > (library
+  >  (name selected)
+  >  (public_name template-middle.selected))
+  > EOF
+  $ echo 'let value = ()' >middle/selected.ml
+
+  $ cat >extra/dune <<'EOF'
+  > (library
+  >  (name selected)
+  >  (public_name template-extra.selected))
+  > EOF
+  $ echo 'let value = ()' >extra/selected.ml
+
+  $ cat >unrelated/dune <<'EOF'
+  > (library
+  >  (name unrelated)
+  >  (public_name template-extra.unrelated))
+  > EOF
+  $ echo 'let value = ()' >unrelated/unrelated.ml
+
+  $ cat >explicit/dune <<'EOF'
+  > (library
+  >  (name explicit)
+  >  (public_name template-explicit))
+  > EOF
+  $ echo 'let value = ()' >explicit/explicit.ml
+
+  $ cat >META.template-explicit.template <<'EOF'
+  > requires += "template-extra.selected"
+  > # DUNE_GEN
+  > EOF
+
+  $ cat >META.template-middle.template <<'EOF'
+  > package "selected" (
+  >  directory = "selected"
+  >  requires = "template-extra.selected"
+  > )
+  > EOF
+
+Ordinary installation continues to accept and install the custom template.
+
+  $ dune build @install
+
+A scoped package dependency currently omits even the ordinary Dune library
+closure. After that closure is added, the template-only edge must not be left
+dangling.
+
+  $ cat >dune <<'EOF'
+  > (rule
+  >  (target recursive)
+  >  (deps (package template-root))
+  >  (action
+  >   (with-stdout-to %{target}
+  >    (run %{bin:ocamlfind} query -recursive template-root))))
+  > (rule
+  >  (target explicit-result)
+  >  (deps (package template-explicit))
+  >  (action
+  >   (with-stdout-to %{target}
+  >    (run %{bin:ocamlfind} query -recursive template-explicit))))
+  > EOF
+
+  $ dune build recursive
+  File "dune", lines 1-6, characters 0-154:
+  1 | (rule
+  2 |  (target recursive)
+  3 |  (deps (package template-root))
+  4 |  (action
+  5 |   (with-stdout-to %{target}
+  6 |    (run %{bin:ocamlfind} query -recursive template-root))))
+  ocamlfind: Package `template-middle.selected' not found - required by `template-root'
+  [1]
+
+The same problem occurs when the dependency-changing template belongs to the
+explicitly requested package.
+
+  $ dune build explicit-result
+  File "dune", lines 7-12, characters 0-168:
+   7 | (rule
+   8 |  (target explicit-result)
+   9 |  (deps (package template-explicit))
+  10 |  (action
+  11 |   (with-stdout-to %{target}
+  12 |    (run %{bin:ocamlfind} query -recursive template-explicit))))
+  ocamlfind: Package `template-extra.selected' not found - required by `template-explicit'
+  [1]