fix(installer): guard the cp and chmod that install helper scripts

With `set -e` off, the installer copied its zfs-replicate, zfs-pre-snapshot, and hypr-live-update-guard scripts into place with bare cp/chmod. A missing or partial source failed silently, leaving a systemd service with a dead ExecStart or a pacman hook pointing at a script that never landed.

The two zfs scripts now install through install_executable, which guards the copy, warns on failure, and skips the chmod when the copy did not land. The two live-update-guard chmods (the guard binary and its hook) are guarded inline with error_warn.

1 files changed, 66 insertions, 0 deletions

diff --git a/tests/installer-steps/test_install_executable.py b/tests/installer-steps/test_install_executable.py
new file mode 100644
index 0000000..6a2ecfd
--- /dev/null
+++ b/tests/installer-steps/test_install_executable.py
@@ -0,0 +1,66 @@
+"""Test the guarded executable install helper.
+
+With `set -e` off, the installer's bare `cp script /usr/local/bin/...` followed
+by `chmod +x` failed silently when the source was missing or partial, leaving a
+systemd service with a dead ExecStart or a pacman hook pointing at a script that
+was never installed. install_executable guards the copy and the chmod, warns on
+failure, and skips the chmod when the copy did not land.
+
+Method: sed-extract install_executable from the real `archsetup` and run it
+against real temp files (no fakes needed) with a fake error_warn recorder.
+
+Run from repo root:
+    python3 -m unittest tests.installer-steps.test_install_executable
+"""
+
+import os
+import subprocess
+import tempfile
+import textwrap
+import unittest
+
+REPO_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+ARCHSETUP = os.path.join(REPO_ROOT, "archsetup")
+
+
+def run(src, dest):
+    script = textwrap.dedent(f"""\
+        logfile=/dev/null
+        error_warn() {{ echo "WARN: $1"; return 1; }}
+        source <(sed -n '/^install_executable() {{/,/^}}/p' "{ARCHSETUP}")
+        install_executable "{src}" "{dest}"
+        echo "RC=$?"
+    """)
+    return subprocess.run(
+        ["bash", "-c", script], capture_output=True, text=True, timeout=10,
+    )
+
+
+class InstallExecutable(unittest.TestCase):
+    def test_copies_and_makes_executable(self):
+        with tempfile.TemporaryDirectory() as d:
+            src = os.path.join(d, "myscript")
+            dest = os.path.join(d, "bin", "myscript")
+            os.mkdir(os.path.join(d, "bin"))
+            with open(src, "w") as f:
+                f.write("#!/bin/sh\necho hi\n")
+            r = run(src, dest)
+            self.assertIn("RC=0", r.stdout)
+            self.assertTrue(os.path.exists(dest))
+            self.assertTrue(os.access(dest, os.X_OK), "dest must be executable")
+            self.assertNotIn("WARN", r.stdout)
+
+    def test_missing_source_warns_and_skips_chmod(self):
+        with tempfile.TemporaryDirectory() as d:
+            src = os.path.join(d, "does-not-exist")
+            dest = os.path.join(d, "bin", "myscript")
+            os.mkdir(os.path.join(d, "bin"))
+            r = run(src, dest)
+            self.assertIn("WARN: copying", r.stdout,
+                          "a failed copy must warn, not silently continue")
+            self.assertNotIn("RC=0", r.stdout, "helper returns non-zero on copy failure")
+            self.assertFalse(os.path.exists(dest))
+
+
+if __name__ == "__main__":
+    unittest.main()