1 files changed, 110 insertions, 0 deletions
diff --git a/tests/installer-steps/test_install_cpu_microcode.py b/tests/installer-steps/test_install_cpu_microcode.py
new file mode 100644
index 0000000..20f1820
--- /dev/null
+++ b/tests/installer-steps/test_install_cpu_microcode.py
@@ -0,0 +1,110 @@
+"""Test install_cpu_microcode — vendor-detected microcode package install.
+
+archsetup never installed intel-ucode/amd-ucode (found on velox 2026-04-10:
+CPU running old microcode, hand-fixed). The step reads vendor_id from
+/proc/cpuinfo and installs the matching package. It must run before
+configure_grub in boot_ux: grub-mkconfig detects /boot/<vendor>-ucode.img for
+its initrd lines, and mkinitcpio's microcode hook embeds it, so the package
+has to exist before either generates.
+
+Method: sed-extract install_cpu_microcode from the real `archsetup`, point it
+at a fixture cpuinfo, fake pacman_install / display / error_warn.
+
+Run from repo root:
+    python3 -m unittest tests.installer-steps.test_install_cpu_microcode
+"""
+
+import os
+import re
+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")
+
+INTEL = "vendor_id\t: GenuineIntel\n"
+AMD = "vendor_id\t: AuthenticAMD\n"
+
+
+def run(cpuinfo_body, missing=False):
+    with tempfile.TemporaryDirectory() as d:
+        cpuinfo = os.path.join(d, "cpuinfo")
+        if not missing:
+            with open(cpuinfo, "w") as f:
+                f.write(cpuinfo_body)
+        script = textwrap.dedent(f"""\
+            logfile=/dev/null
+            action=""
+            display() {{ :; }}
+            pacman_install() {{ echo "INSTALL: $1"; }}
+            error_warn() {{ echo "WARN: $1"; return 1; }}
+            source <(sed -n '/^install_cpu_microcode() {{/,/^}}/p' "{ARCHSETUP}")
+            install_cpu_microcode "{cpuinfo}"
+            echo "RC=$?"
+            exit 0
+        """)
+        return subprocess.run(
+            ["bash", "-c", script], capture_output=True, text=True, timeout=10,
+        )
+
+
+def rc_of(r):
+    m = re.search(r"^RC=(\d+)$", r.stdout, re.M)
+    assert m, "no RC line in output: %r / %r" % (r.stdout, r.stderr)
+    return int(m.group(1))
+
+
+class InstallCpuMicrocode(unittest.TestCase):
+    # ------------------------------------------------------------ normal ----
+    def test_intel_vendor_installs_intel_ucode(self):
+        r = run(f"processor\t: 0\n{INTEL}model name\t: whatever\n")
+        self.assertIn("INSTALL: intel-ucode", r.stdout)
+        self.assertNotIn("amd-ucode", r.stdout)
+        self.assertEqual(rc_of(r), 0)
+
+    def test_amd_vendor_installs_amd_ucode(self):
+        r = run(f"processor\t: 0\n{AMD}")
+        self.assertIn("INSTALL: amd-ucode", r.stdout)
+        self.assertNotIn("intel-ucode", r.stdout)
+        self.assertEqual(rc_of(r), 0)
+
+    # ---------------------------------------------------------- boundary ----
+    def test_multicore_cpuinfo_installs_exactly_once(self):
+        # /proc/cpuinfo repeats vendor_id per logical CPU.
+        body = "".join(f"processor\t: {i}\n{AMD}\n" for i in range(16))
+        r = run(body)
+        self.assertEqual(r.stdout.count("INSTALL:"), 1,
+                         "one package install, not one per core")
+
+    def test_space_separated_vendor_line_parses(self):
+        # Some kernels/arches pad with spaces rather than a tab.
+        r = run("vendor_id       : GenuineIntel\n")
+        self.assertIn("INSTALL: intel-ucode", r.stdout)
+
+    def test_vendor_id_substring_elsewhere_does_not_confuse(self):
+        # A flags line or model name mentioning a vendor string must not win
+        # over the real vendor_id line.
+        body = "model name\t: AuthenticAMD emulator\n" + INTEL
+        r = run(body)
+        self.assertIn("INSTALL: intel-ucode", r.stdout)
+        self.assertNotIn("amd-ucode", r.stdout)
+
+    # ------------------------------------------------------------- error ----
+    def test_unknown_vendor_warns_and_installs_nothing(self):
+        r = run("vendor_id\t: CentaurHauls\n")
+        self.assertNotIn("INSTALL:", r.stdout)
+        self.assertIn("WARN:", r.stdout)
+        self.assertEqual(rc_of(r), 1)
+
+    def test_missing_cpuinfo_warns_and_installs_nothing(self):
+        r = run("", missing=True)
+        self.assertNotIn("INSTALL:", r.stdout)
+        self.assertIn("WARN:", r.stdout)
+        self.assertEqual(rc_of(r), 1)
+        self.assertEqual(r.returncode, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()