Add reftable test

gix-discover/tests/discover/is_git/mod.rs

@@ -130,3 +130,11 @@ fn split_worktree_using_configuration() -> crate::Result {
     }
     Ok(())
 }
+
+#[test]
+fn reftable() -> crate::Result {
+    let repo = gix_testtools::scripted_fixture_read_only("make_reftable_repo.sh")?.join("reftable-clone");
+    let kind = gix_discover::is_git(&repo)?;
+    assert_eq!(kind, gix_discover::repository::Kind::WorkTree { linked_git_dir: None });
+    Ok(())
+}

gix-discover/tests/fixtures/make_reftable_repo.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -eu -o pipefail
+
+git init -q
+
+git checkout -b main
+touch this
+git add this
+git commit -q -m c1
+echo hello >> this
+git commit -q -am c2
+
+git clone --ref-format=reftable . reftable-clone