add _format_cert_table() helper for CLI cert listings

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/test_cli.py

@@ -150,6 +150,63 @@ def test_regen_crl_calls_gen_and_copy(monkeypatch, capsys):
     assert "CRL" in capsys.readouterr().out
 
 
+# ---------------------------------------------------------------------------
+# _format_cert_table
+# ---------------------------------------------------------------------------
+
+def test_format_cert_table_empty_list():
+    import openvpncertupdate
+    assert openvpncertupdate._format_cert_table([]) == "(no certificates)"
+
+
+def test_format_cert_table_header_and_columns(monkeypatch):
+    import openvpncertupdate
+    certs = [
+        openvpncertupdate.CertInfo(cn="alice", expires=None, days_left=24),
+        openvpncertupdate.CertInfo(cn="bob",   expires=None, days_left=-5),
+    ]
+    monkeypatch.setattr(
+        "openvpncertupdate.get_email",
+        MagicMock(side_effect=lambda pki, cn: {"alice": "alice@example.com"}.get(cn, "")),
+    )
+    table = openvpncertupdate._format_cert_table(certs)
+    lines = table.splitlines()
+    assert lines[0].split() == ["CN", "EXPIRES", "EMAIL"]
+    assert len(lines) == 3
+
+
+def test_format_cert_table_shows_email_and_none_placeholder(monkeypatch):
+    import openvpncertupdate
+    certs = [
+        openvpncertupdate.CertInfo(cn="alice", expires=None, days_left=24),
+        openvpncertupdate.CertInfo(cn="bob",   expires=None, days_left=-5),
+    ]
+    monkeypatch.setattr(
+        "openvpncertupdate.get_email",
+        MagicMock(side_effect=lambda pki, cn: {"alice": "alice@example.com"}.get(cn, "")),
+    )
+    table = openvpncertupdate._format_cert_table(certs)
+    lines = table.splitlines()
+    assert "alice@example.com" in lines[1]
+    assert "(none)" in lines[2]
+
+
+def test_format_cert_table_columns_are_aligned(monkeypatch):
+    import openvpncertupdate
+    certs = [
+        openvpncertupdate.CertInfo(cn="a",            expires=None, days_left=24),
+        openvpncertupdate.CertInfo(cn="a-much-longer", expires=None, days_left=5),
+    ]
+    monkeypatch.setattr("openvpncertupdate.get_email", MagicMock(return_value=""))
+    table = openvpncertupdate._format_cert_table(certs)
+    lines = table.splitlines()
+    # The EMAIL column must start at the same character offset on every row.
+    email_col = len(lines[0]) - len("EMAIL")
+    for line in lines[1:]:
+        assert line.rstrip().endswith("(none)")
+        assert line.index("(none)") == email_col
+
+
 # ---------------------------------------------------------------------------
 # main() argument dispatch
 # ---------------------------------------------------------------------------