test: cover disk_in_use and network_available failure paths

These two boundary functions backed the pre-flight guards from #215 but had no unit coverage of their own. The VM harness exercised them instead. I added 7 bats tests that mock the system commands they query, so the real branching logic runs.

test_disk.bats covers disk_in_use across mountpoint, active swap, imported-zpool member, and idle — that's the gate that refuses to wipe an already-mounted disk. test_archangel.bats covers network_available for DNS failure, TCP-connect failure, and success, the check that fails the install before pacstrap. The /proc/mdstat-positive branch and the live probes stay in the VM harness, since neither drives cleanly without writing to /proc or hitting the network. Suite 238 to 245, lint clean.

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/unit/test_archangel.bats b/tests/unit/test_archangel.bats
index c38dcb8..645b6e6 100644
--- a/tests/unit/test_archangel.bats
+++ b/tests/unit/test_archangel.bats
@@ -372,3 +372,32 @@ setup() {
     run validate_install_targets
     [ "$status" -eq 0 ]
 }
+
+#############################
+# network_available
+#############################
+# The two probes it composes — DNS via getent and a TCP-443 open via
+# timeout+bash /dev/tcp — are the system boundary; mocking them drives the
+# fail-fast wiring without a live network. The real probe runs in the VM
+# harness. These pin the "network failure before pacstrap" error path that
+# validate_install_targets surfaces.
+
+@test "network_available returns 1 when DNS resolution fails" {
+    getent() { return 1; }
+    run network_available
+    [ "$status" -eq 1 ]
+}
+
+@test "network_available returns 1 when DNS resolves but the TCP connect fails" {
+    getent() { return 0; }
+    timeout() { return 1; }
+    run network_available
+    [ "$status" -eq 1 ]
+}
+
+@test "network_available returns 0 when DNS resolves and the TCP connect opens" {
+    getent() { return 0; }
+    timeout() { return 0; }
+    run network_available
+    [ "$status" -eq 0 ]
+}