fix: improve parser robustness for real-world tech output by lbruton · Pull Request #5 · lbruton/TRMCompare

lbruton · 2026-04-06T19:04:18Z

Summary

Abbreviated command support — PROMPT_RE matches sh as well as show; new alias map resolves sh cdp nei, int stat, mac ad, etc.
New parsers — parseInterfaceStatus() for show interfaces status and parseLldpNeighbors() for show lldp neighbors, both backward-compatible with existing enrichment consumers
CDP multi-line fix — handles long device IDs that wrap to the next line
Better error messaging — missing MAC table now lists which commands were detected instead of a generic error
Noise reduction — skips VLAN "All" CPU entries, smarter fallback avoids 1500+ false errors in multi-command mode

Closes TRMC-12

Test plan

Production before file: detects hostname, 17 interfaces (with descriptions + VLANs from show interfaces status), 1 CDP neighbor, 15 VLANs — 0 false MAC errors
Production after file: 253 MAC entries, 2 errors (down from 23), CDP + LLDP + interface descriptions + VLANs all parsed
Existing sample data (before-ie3000.txt, after-ie3300.txt) parses identically — backward compatible
Visual smoke test in browser with production data

🤖 Generated with Claude Code

First production test revealed the parser couldn't handle typical field tech terminal captures. Three categories of fixes: 1. Abbreviated commands — PROMPT_RE now matches `sh` as well as `show`, and a new COMMAND_ALIASES map resolves `sh cdp nei`, `int stat`, `mac ad`, etc. to their canonical forms. 2. New parsers — `parseInterfaceStatus()` handles `show interfaces status` (different columns than `show interfaces description`), and `parseLldpNeighbors()` handles `show lldp neighbors`. Both populate existing enrichment fields for backward compatibility. 3. CDP multi-line — `parseCdpNeighbors()` now handles long device IDs that wrap to the next line (common in production). Also: skip VLAN "All" CPU entries, smarter fallback in multi-command mode (no more 1500+ false errors), and informative missing-MAC-table messages that list which commands were actually detected. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

codacy-production · 2026-04-06T19:05:04Z

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 57 complexity · 0 duplication

Metric Results

Complexity ✅ 57 (≤ 500 complexity)

Duplication ✅ 0 (≤ 4 duplication)

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gemini-code-assist

Code Review

This pull request significantly enhances the Cisco command parsing logic by introducing support for command abbreviations, 'show interfaces status', and 'show lldp neighbors'. It also improves the CDP neighbor parser to handle multi-line output for long hostnames and adds a detailed error reporting mechanism for missing MAC address-table data. Review feedback highlights an opportunity to prevent silent data loss for unrecognized commands in the splitter and suggests refactoring duplicated regex patterns into module-level constants to improve maintainability.

gemini-code-assist · 2026-04-06T19:06:51Z

js/parser.js

+    const canonical = resolveCommand(showArgs);
+    if (!canonical) continue;


The resolveCommand function returns null if the command is not found, but the caller does not handle the case where a command is missing from the recognized list but still present in the input. This could lead to silent data loss for commands that are not in the RECOGNIZED_COMMANDS list but are still valid show commands.

gemini-code-assist · 2026-04-06T19:06:51Z

js/parser.js

+  if (!text) return result;
+
+  const lines = text.split('\n');
+  const PORT_PATTERN = /(?:Gig(?:abitEthernet)?|Fas(?:tEthernet)?|Ten(?:GigabitEthernet)?|Eth(?:ernet)?|Twe(?:ntyFiveGigE)?|Po(?:rt-channel)?|Gi|Te|Fa)\s*[\d/]+/i;


The PORT_PATTERN regex is duplicated across multiple functions (parseCdpNeighbors and parseLldpNeighbors). It should be defined as a constant at the module level to improve maintainability and ensure consistency.

Copilot

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Improves the terminal-output parser to better handle real-world Cisco CLI pastes (abbreviated commands, multi-line CDP entries, and new interface/LLDP parsers) while reducing noise and improving UI error messaging.

Changes:

Added abbreviated sh ... prompt support and a command-alias resolver for multi-command splitting.
Introduced parseInterfaceStatus() and parseLldpNeighbors() and wired them into parseTerminalOutput() with backward-compat fallbacks.
Improved MAC parsing noise reduction and UI messaging when MAC-table data is missing.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 9 comments.

File	Description
samples/production-before.txt	Adds a large real-world capture used to validate parsing robustness (but currently contains sensitive data).
samples/production-after.txt	Adds a real-world capture focused on MAC/interface/VLAN/CDP/LLDP outputs for parser validation.
js/parser.js	Extends command splitting, adds new parsers (interfaces status + LLDP), improves CDP wrap handling, and reduces MAC parsing noise/fallback errors.
js/app.js	Improves missing-MAC-table UI errors by listing detected commands/hostname.

Comments suppressed due to low confidence (1)

js/parser.js:1

commandsFound is currently derived from the presence of parsed data objects, but some of those objects are now synthesized for backward compatibility (e.g., interfaceDesc derived from interfaces status, cdpNeighbors derived from lldp neighbors). This can cause the UI to report commands as “detected” even when they weren’t present in the paste; track “seen commands” separately from “derived compatibility data” (e.g., sawInterfacesDescription, sawInterfacesStatus, sawCdp, sawLldp) and build commandsFound from the saw-flags only.

// Cisco MAC address table parser

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Copilot · 2026-04-06T19:12:16Z

samples/production-before.txt

+enable secret 9 $9$Ul64Po8JxM16t0$w6E3BBfxG60Ju2uyQ7l.FCFUFhOpBuScSJmC8vznkMQ
+!
+username svc_prime privilege 15 secret 9 $9$YvhRekuD07VDGU$6YyzIyKySN6ltDorL8VbnLQN96Ft7qZStCW5Ug0E2zg


The repository is committing production configuration secrets/credentials (enable secret, user secrets, SNMP community strings, TACACS keys, etc.). Even if some are hashed/obfuscated, they are still sensitive and should not be stored in-source; please remove this sample or heavily sanitize it (redact secrets/communities/keys/usernames, consider replacing hostnames/IPs too) and add guidance for generating sanitized fixtures if needed.

Copilot · 2026-04-06T19:12:17Z

samples/production-before.txt

+!
+snmp-server group DNACGROUPAuthPriv v3 priv read DNAC-ACCESS write DNAC-ACCESS 
+snmp-server view DNAC-ACCESS iso included
+snmp-server community aOR!75Nm7b RO 11


The repository is committing production configuration secrets/credentials (enable secret, user secrets, SNMP community strings, TACACS keys, etc.). Even if some are hashed/obfuscated, they are still sensitive and should not be stored in-source; please remove this sample or heavily sanitize it (redact secrets/communities/keys/usernames, consider replacing hostnames/IPs too) and add guidance for generating sanitized fixtures if needed.

Copilot · 2026-04-06T19:12:17Z

samples/production-before.txt

+tacacs server tacacs-tulpaipn06
+ address ipv4 172.25.84.55
+ key 7 144F3E5D464E2C79092022052A50570137
+ timeout 5
+ single-connection
+tacacs server tacacs-edcpaipn06
+ address ipv4 172.30.84.55
+ key 7 135D3B4441460278062C39033D61431022
+ timeout 5
+ single-connection
+tacacs server tacacs-drrpaipn05
+ address ipv4 172.20.204.54
+ key 7 135D3B4441460278062C39033D61431022


The repository is committing production configuration secrets/credentials (enable secret, user secrets, SNMP community strings, TACACS keys, etc.). Even if some are hashed/obfuscated, they are still sensitive and should not be stored in-source; please remove this sample or heavily sanitize it (redact secrets/communities/keys/usernames, consider replacing hostnames/IPs too) and add guidance for generating sanitized fixtures if needed.

Suggested change

tacacs server tacacs-tulpaipn06

address ipv4 172.25.84.55

key 7 144F3E5D464E2C79092022052A50570137

timeout 5

single-connection

tacacs server tacacs-edcpaipn06

address ipv4 172.30.84.55

key 7 135D3B4441460278062C39033D61431022

timeout 5

single-connection

tacacs server tacacs-drrpaipn05

address ipv4 172.20.204.54

key 7 135D3B4441460278062C39033D61431022

tacacs server tacacs-server-01

address ipv4 192.0.2.10

key 7 REDACTED_SANITIZED_SAMPLE

timeout 5

single-connection

tacacs server tacacs-server-02

address ipv4 192.0.2.11

key 7 REDACTED_SANITIZED_SAMPLE

timeout 5

single-connection

tacacs server tacacs-server-03

address ipv4 192.0.2.12

key 7 REDACTED_SANITIZED_SAMPLE

Copilot · 2026-04-06T19:12:17Z

js/parser.js

+    // Last token is remote port ID
+    const remotePort = parts.length > 0 ? parts[parts.length - 1] : '';

-    result.set(localPort, { deviceId, platform, remotePort });
+    result.set(localPort, { deviceId, platform: 'LLDP', remotePort });


parseLldpNeighbors() returns remotePort un-normalized, while parseCdpNeighbors() normalizes remote port names via normalizePort(). This breaks the “same shape / interchangeability” guarantee and can lead to mismatches in downstream enrichment/comparison; normalize the LLDP remotePort the same way (while leaving non-interface IDs like port-001 unchanged).

Copilot · 2026-04-06T19:12:18Z

js/parser.js

+      } else if (cmd.includes('interfaces status')) {
+        result.interfaceStatus = parseInterfaceStatus(block.text);
+        // Also populate interfaceDesc from status data for backward compatibility
+        if (!result.interfaceDesc) {
+          result.interfaceDesc = result.interfaceStatus.descriptions;
+        }
      } else if (cmd.includes('cdp neighbors')) {
        result.cdpNeighbors = parseCdpNeighbors(block.text);
+      } else if (cmd.includes('lldp neighbors')) {
+        result.lldpNeighbors = parseLldpNeighbors(block.text);
+        // Also populate cdpNeighbors from LLDP for backward compatibility
+        if (!result.cdpNeighbors) {
+          result.cdpNeighbors = result.lldpNeighbors;
+        }


commandsFound is currently derived from the presence of parsed data objects, but some of those objects are now synthesized for backward compatibility (e.g., interfaceDesc derived from interfaces status, cdpNeighbors derived from lldp neighbors). This can cause the UI to report commands as “detected” even when they weren’t present in the paste; track “seen commands” separately from “derived compatibility data” (e.g., sawInterfacesDescription, sawInterfacesStatus, sawCdp, sawLldp) and build commandsFound from the saw-flags only.

Copilot · 2026-04-06T19:12:18Z

js/parser.js

+ *
+ * @param {string} text - Raw command output
+ * @returns {{ descriptions: Map<string, { status: string, protocol: string, description: string }>,
+ *             portVlans: Map<string, number|'trunk'> }}


The JSDoc return type for portVlans doesn’t match behavior: the implementation can set 'routed', but the doc says number|'trunk'. Update the doc (and any consuming type assumptions) to include 'routed' or adjust the implementation to match the declared return shape.

Suggested change

* portVlans: Map<string, number|'trunk'> }}

* portVlans: Map<string, number|'trunk'|'routed'> }}

Copilot · 2026-04-06T19:12:18Z

js/parser.js

+    if (vlanField.toLowerCase() === 'trunk') {
+      portVlans.set(port, 'trunk');
+    } else if (vlanField.toLowerCase() === 'routed') {
+      portVlans.set(port, 'routed');


The JSDoc return type for portVlans doesn’t match behavior: the implementation can set 'routed', but the doc says number|'trunk'. Update the doc (and any consuming type assumptions) to include 'routed' or adjust the implementation to match the declared return shape.

Copilot · 2026-04-06T19:12:18Z

js/parser.js

+ * Abbreviation map: maps common abbreviated command forms to their canonical form.
+ * Checked before RECOGNIZED_COMMANDS matching. Order: most specific first.


The comment states aliases are “checked before RECOGNIZED_COMMANDS matching,” but resolveCommand() has no fallback to match RECOGNIZED_COMMANDS. Either implement the fallback (so full canonical commands don’t need to be duplicated in COMMAND_ALIASES) or update the comment/structure to reflect that aliases are the sole recognition mechanism.

Suggested change

* Abbreviation map: maps common abbreviated command forms to their canonical form.

* Checked before RECOGNIZED_COMMANDS matching. Order: most specific first.

* Abbreviation map: maps abbreviated and canonical command forms to their canonical form.

* Entries are matched in order, so keep the most specific forms first.

* Canonical commands must also appear here if they should be recognized directly.

Copilot · 2026-04-06T19:12:19Z

js/parser.js

+function resolveCommand(showArgs) {
+  const lower = showArgs.toLowerCase();
+  for (const [abbrev, canonical] of COMMAND_ALIASES) {
+    if (lower.startsWith(abbrev)) return canonical;
+  }
+  return null;
+}


The comment states aliases are “checked before RECOGNIZED_COMMANDS matching,” but resolveCommand() has no fallback to match RECOGNIZED_COMMANDS. Either implement the fallback (so full canonical commands don’t need to be duplicated in COMMAND_ALIASES) or update the comment/structure to reflect that aliases are the sole recognition mechanism.

Copilot AI review requested due to automatic review settings April 6, 2026 19:04

gemini-code-assist bot reviewed Apr 6, 2026

View reviewed changes

Copilot AI reviewed Apr 6, 2026

View reviewed changes

Copilot started reviewing on behalf of lbruton April 6, 2026 20:44 View session

		const canonical = resolveCommand(showArgs);
		if (!canonical) continue;

	* portVlans: Map<string, number\|'trunk'> }}
	* portVlans: Map<string, number\|'trunk'\|'routed'> }}

		* Abbreviation map: maps common abbreviated command forms to their canonical form.
		* Checked before RECOGNIZED_COMMANDS matching. Order: most specific first.

- * Abbreviation map: maps common abbreviated command forms to their canonical form.
- * Checked before RECOGNIZED_COMMANDS matching. Order: most specific first.
+ * Abbreviation map: maps abbreviated and canonical command forms to their canonical form.
+ * Entries are matched in order, so keep the most specific forms first.
+ * Canonical commands must also appear here if they should be recognized directly.

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lbruton commented Apr 6, 2026

Summary

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codacy-production bot commented Apr 6, 2026

Up to standards ✅

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