From aa8f3f66fc4b034f6033dda1bd05977949d82f07 Mon Sep 17 00:00:00 2001
From: Ali Caglayan <alizter@gmail.com>
Date: Sat, 17 Oct 2026 22:25:09 +0200
Subject: [PATCH] test(sandbox): cover directory copy actions across sandbox
 modes

Exercise a directory copy action with a generated directory dependency,
without Melange or package management. Record the current behavior in
symlink, copy, and hardlink sandbox modes before changing input traversal.

Signed-off-by: Ali Caglayan <alizter@gmail.com>
---
 .../test-cases/sandbox/copy-dir-deps.t        | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 test/blackbox-tests/test-cases/sandbox/copy-dir-deps.t

diff --git a/test/blackbox-tests/test-cases/sandbox/copy-dir-deps.t b/test/blackbox-tests/test-cases/sandbox/copy-dir-deps.t
new file mode 100644
index 00000000000..65494e18976
--- /dev/null
+++ b/test/blackbox-tests/test-cases/sandbox/copy-dir-deps.t
@@ -0,0 +1,44 @@
+A copy action on a directory dependency should produce regular files in every
+sandbox mode. This case has no overlapping dependencies.
+
+  $ make_dune_project 3.25
+  $ cat > dune <<'EOF'
+  > (rule
+  >  (target (dir tree))
+  >  (action (system "mkdir tree && echo contents > tree/file")))
+  > (rule
+  >  (target (dir copied))
+  >  (deps tree (sandbox always))
+  >  (action (no-infer (copy tree copied))))
+  > EOF
+
+First check that the directory dependency contains a regular file.
+
+  $ dune build tree/file
+  $ dune_cmd stat kind _build/default/tree/file
+  regular file
+
+Symlink mode: the copy action follows the directory link and copies its files.
+
+  $ dune build copied --sandbox symlink
+  $ cat _build/default/copied/file
+  contents
+  $ dune_cmd stat kind _build/default/copied/file
+  regular file
+
+Copy mode also produces a regular file with the expected contents.
+
+  $ dune build copied --sandbox copy
+  $ cat _build/default/copied/file
+  contents
+  $ dune_cmd stat kind _build/default/copied/file
+  regular file
+
+Hardlink mode currently fails while populating the directory dependency,
+before the copy action runs.
+
+  $ dune build copied --sandbox hardlink 2>&1 | censor
+  Error:
+  link(_build/.sandbox/$DIGEST/default/tree): Operation not permitted
+  -> required by _build/default/copied
+  [1]