test: expand diagnose test coverage — parsers, dmesg, lldp, and analyze

Add 47 new tests covering parse_ethtool_driver, parse_nic_stats,
parse_ethtool_dom (SFP DOM), parse_ip_link, parse_dmesg, parse_lldpctl,
and the analyze() health-analysis method with all issue/warning/info
code paths (NO_CARRIER, HALF_DUPLEX, SPEED_MISMATCH, SFP thresholds,
CRC errors, carrier flapping, LLDP mismatch/missing).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_diagnose.py

@@ -3,7 +3,7 @@ import sys
 import os
 sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
 
-from diagnose import DiagnosticsRunner
+from diagnose import DiagnosticsRunner  # noqa: E402
 
 
 # ── build_ssh_command ────────────────────────────────────────────────────────
@@ -215,3 +215,265 @@ class TestParseEthtool:
 
     def test_empty_returns_empty(self):
         assert DiagnosticsRunner.parse_ethtool('') == {}
+
+
+# ── parse_ethtool_driver ──────────────────────────────────────────────────────
+
+class TestParseEthtoolDriver:
+    def test_driver_name(self):
+        text = "driver: igb\nversion: 5.6.0-k\nfirmware-version: 1.67\nbus-info: 0000:03:00.0\n"
+        result = DiagnosticsRunner.parse_ethtool_driver(text)
+        assert result['driver'] == 'igb'
+
+    def test_version(self):
+        text = "driver: igb\nversion: 5.6.0-k\n"
+        result = DiagnosticsRunner.parse_ethtool_driver(text)
+        assert result['version'] == '5.6.0-k'
+
+    def test_firmware_version(self):
+        text = "firmware-version: 1.67, 0x80000d38\n"
+        result = DiagnosticsRunner.parse_ethtool_driver(text)
+        assert result['firmware_version'] == '1.67, 0x80000d38'
+
+    def test_bus_info(self):
+        text = "bus-info: 0000:03:00.0\n"
+        result = DiagnosticsRunner.parse_ethtool_driver(text)
+        assert result['bus_info'] == '0000:03:00.0'
+
+    def test_empty_returns_empty(self):
+        assert DiagnosticsRunner.parse_ethtool_driver('') == {}
+
+
+# ── parse_nic_stats ───────────────────────────────────────────────────────────
+
+class TestParseNicStats:
+    def test_parses_integer_values(self):
+        text = "rx_packets: 1234\ntx_packets: 5678\n"
+        result = DiagnosticsRunner.parse_nic_stats(text)
+        assert result['rx_packets'] == 1234
+        assert result['tx_packets'] == 5678
+
+    def test_non_numeric_skipped(self):
+        text = "rx_packets: 100\nbad_stat: N/A\n"
+        result = DiagnosticsRunner.parse_nic_stats(text)
+        assert 'bad_stat' not in result
+        assert result['rx_packets'] == 100
+
+    def test_empty_returns_empty(self):
+        assert DiagnosticsRunner.parse_nic_stats('') == {}
+
+
+# ── parse_ethtool_dom ─────────────────────────────────────────────────────────
+
+class TestParseEthtoolDom:
+    def test_unsupported_returns_empty(self):
+        assert DiagnosticsRunner.parse_ethtool_dom('Cannot get module EEPROM information') == {}
+
+    def test_empty_returns_empty(self):
+        assert DiagnosticsRunner.parse_ethtool_dom('') == {}
+
+    def test_vendor_name(self):
+        text = "Vendor name               : CISCO-FINISAR\n"
+        result = DiagnosticsRunner.parse_ethtool_dom(text)
+        assert result['vendor'] == 'CISCO-FINISAR'
+
+    def test_wavelength(self):
+        text = "Laser wavelength          : 1310 nm\n"
+        result = DiagnosticsRunner.parse_ethtool_dom(text)
+        assert result['wavelength_nm'] == 1310
+
+    def test_tx_power_dbm(self):
+        text = "Laser output power        : 0.3000 mW / -5.23 dBm\n"
+        result = DiagnosticsRunner.parse_ethtool_dom(text)
+        assert abs(result['tx_power_dbm'] - (-5.23)) < 0.01
+
+    def test_rx_power_dbm(self):
+        text = "Receiver signal average optical power : 0.1000 mW / -10.00 dBm\n"
+        result = DiagnosticsRunner.parse_ethtool_dom(text)
+        assert abs(result['rx_power_dbm'] - (-10.00)) < 0.01
+
+
+# ── parse_ip_link ─────────────────────────────────────────────────────────────
+
+class TestParseIpLink:
+    IP_LINK_SAMPLE = """\
+2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
+    link/ether aa:bb:cc:dd:ee:ff brd ff:ff:ff:ff:ff:ff
+    RX:  bytes  packets errors dropped  missed   mcast
+      123456789  1000000      0       5       0       0
+    TX:  bytes  packets errors dropped carrier collsns
+       98765432   900000      0       0       0       0
+"""
+
+    def test_mtu_parsed(self):
+        result = DiagnosticsRunner.parse_ip_link(self.IP_LINK_SAMPLE)
+        assert result['mtu'] == 1500
+
+    def test_state_parsed(self):
+        result = DiagnosticsRunner.parse_ip_link(self.IP_LINK_SAMPLE)
+        assert result['state'] == 'up'
+
+    def test_rx_bytes(self):
+        result = DiagnosticsRunner.parse_ip_link(self.IP_LINK_SAMPLE)
+        assert result['ip_rx_bytes'] == 123456789
+
+    def test_tx_bytes(self):
+        result = DiagnosticsRunner.parse_ip_link(self.IP_LINK_SAMPLE)
+        assert result['ip_tx_bytes'] == 98765432
+
+    def test_rx_dropped(self):
+        result = DiagnosticsRunner.parse_ip_link(self.IP_LINK_SAMPLE)
+        assert result['ip_rx_dropped'] == 5
+
+    def test_empty_returns_empty(self):
+        assert DiagnosticsRunner.parse_ip_link('') == {}
+
+
+# ── parse_dmesg ───────────────────────────────────────────────────────────────
+
+class TestParseDmesg:
+    def test_error_severity(self):
+        text = "[  1.234567] eth0: Link failure detected\n"
+        events = DiagnosticsRunner.parse_dmesg(text)
+        assert len(events) == 1
+        assert events[0]['severity'] == 'error'
+
+    def test_warn_severity(self):
+        text = "[  2.000000] eth0: dropped packet\n"
+        events = DiagnosticsRunner.parse_dmesg(text)
+        assert events[0]['severity'] == 'warn'
+
+    def test_info_severity(self):
+        text = "[  3.000000] eth0: NIC Link is Up\n"
+        events = DiagnosticsRunner.parse_dmesg(text)
+        assert events[0]['severity'] == 'info'
+
+    def test_timestamp_extracted(self):
+        text = "[  5.678900] eth0: reset\n"
+        events = DiagnosticsRunner.parse_dmesg(text)
+        assert events[0]['timestamp'] == '5.678900'
+
+    def test_no_timestamp(self):
+        text = "eth0: some timeout event\n"
+        events = DiagnosticsRunner.parse_dmesg(text)
+        assert events[0]['timestamp'] == ''
+        assert events[0]['severity'] == 'error'
+
+    def test_empty_returns_empty_list(self):
+        assert DiagnosticsRunner.parse_dmesg('') == []
+
+
+# ── parse_lldpctl ─────────────────────────────────────────────────────────────
+
+class TestParseLldpctl:
+    def test_unavailable_when_not_running(self):
+        result = DiagnosticsRunner.parse_lldpctl('lldpd not running')
+        assert result == {'available': False}
+
+    def test_unavailable_on_empty(self):
+        result = DiagnosticsRunner.parse_lldpctl('')
+        assert result == {'available': False}
+
+    def test_neighbor_system_parsed(self):
+        text = "  SysName: core-sw-01\n  PortID: Gi1/0/5\n  ChassisID: aa:bb:cc:dd:ee:ff\n"
+        result = DiagnosticsRunner.parse_lldpctl(text)
+        assert result['available'] is True
+        assert result['neighbor_system'] == 'core-sw-01'
+
+    def test_neighbor_port_parsed(self):
+        text = "  SysName: core-sw-01\n  PortID: Gi1/0/5\n"
+        result = DiagnosticsRunner.parse_lldpctl(text)
+        assert result['neighbor_port'] == 'Gi1/0/5'
+
+    def test_chassis_id_parsed(self):
+        text = "  ChassisID: aa:bb:cc:dd:ee:ff\n"
+        result = DiagnosticsRunner.parse_lldpctl(text)
+        assert result['neighbor_chassis_id'] == 'aa:bb:cc:dd:ee:ff'
+
+
+# ── analyze ───────────────────────────────────────────────────────────────────
+
+class TestAnalyze:
+    def _sections(self, **overrides):
+        base = {
+            'carrier': '1',
+            'operstate': 'up',
+            'ethtool': {'link_detected': True, 'duplex': 'full', 'speed_mbps': 1000},
+            'sysfs_stats': {'rx_crc_errors': 0},
+            'ethtool_dom': {},
+            'dmesg': [],
+            'lldpctl': {'available': False},
+            'carrier_changes': 0,
+        }
+        base.update(overrides)
+        return base
+
+    def test_no_carrier_is_issue(self):
+        result = DiagnosticsRunner.analyze(self._sections(carrier='0'), {})
+        codes = [i['code'] for i in result['issues']]
+        assert 'NO_CARRIER' in codes
+
+    def test_half_duplex_is_issue(self):
+        sections = self._sections(ethtool={'duplex': 'half', 'link_detected': True, 'speed_mbps': 1000})
+        result = DiagnosticsRunner.analyze(sections, {})
+        codes = [i['code'] for i in result['issues']]
+        assert 'HALF_DUPLEX' in codes
+
+    def test_speed_mismatch_is_warning(self):
+        result = DiagnosticsRunner.analyze(
+            self._sections(ethtool={'duplex': 'full', 'link_detected': True, 'speed_mbps': 100}),
+            {'speed_mbps': 1000}
+        )
+        codes = [w['code'] for w in result['warnings']]
+        assert 'SPEED_MISMATCH' in codes
+
+    def test_sfp_rx_critical_low(self):
+        sections = self._sections(ethtool_dom={'rx_power_dbm': -30.0})
+        result = DiagnosticsRunner.analyze(sections, {})
+        codes = [i['code'] for i in result['issues']]
+        assert 'SFP_RX_CRITICAL' in codes
+
+    def test_sfp_rx_low_is_warning(self):
+        sections = self._sections(ethtool_dom={'rx_power_dbm': -20.0})
+        result = DiagnosticsRunner.analyze(sections, {})
+        codes = [w['code'] for w in result['warnings']]
+        assert 'SFP_RX_LOW' in codes
+
+    def test_high_crc_is_issue(self):
+        sections = self._sections(sysfs_stats={'rx_crc_errors': 200})
+        result = DiagnosticsRunner.analyze(sections, {})
+        codes = [i['code'] for i in result['issues']]
+        assert 'CRC_ERRORS_HIGH' in codes
+
+    def test_low_crc_is_warning(self):
+        sections = self._sections(sysfs_stats={'rx_crc_errors': 50})
+        result = DiagnosticsRunner.analyze(sections, {})
+        codes = [w['code'] for w in result['warnings']]
+        assert 'CRC_ERRORS_LOW' in codes
+
+    def test_carrier_flapping_issue(self):
+        result = DiagnosticsRunner.analyze(self._sections(carrier_changes=150), {})
+        codes = [i['code'] for i in result['issues']]
+        assert 'CARRIER_FLAPPING' in codes
+
+    def test_carrier_flaps_warning(self):
+        result = DiagnosticsRunner.analyze(self._sections(carrier_changes=25), {})
+        codes = [w['code'] for w in result['warnings']]
+        assert 'CARRIER_FLAPS' in codes
+
+    def test_lldp_missing_is_info(self):
+        result = DiagnosticsRunner.analyze(self._sections(lldpctl={'available': False}), {})
+        codes = [i['code'] for i in result['info']]
+        assert 'LLDP_MISSING' in codes
+
+    def test_lldp_mismatch_is_warning(self):
+        sections = self._sections(lldpctl={'available': True, 'neighbor_system': 'wrong-switch'})
+        switch_data = {'speed_mbps': 1000, 'lldp': {'system_name': 'core-sw-01'}}
+        result = DiagnosticsRunner.analyze(sections, switch_data)
+        codes = [w['code'] for w in result['warnings']]
+        assert 'LLDP_MISMATCH' in codes
+
+    def test_healthy_link_no_issues(self):
+        result = DiagnosticsRunner.analyze(self._sections(), {})
+        assert result['issues'] == []
+        assert result['warnings'] == []