Add channel settings tab demo

[nickmisasi]

Summary

• Register a ChannelSettingsTab pluggable to smoke-test the new channel settings tab plugin API
• Add a minimal ChannelSettingsSmokeTest component that renders channel info, a dirty-state input, and a tab-switch error banner
• Make GetTeams() calls non-fatal in ensureDemoUser, ensureDemoChannels, OnActivate, and OnDeactivate so the plugin can start even when the Teams table has NULL string columns (core server bug where CompanyName is NULL)
  Needs Support pluggable channel settings tabs mattermost#35591

Test plan

• Build and deploy the plugin to a Mattermost instance with channel settings pluggable support
• Open Channel Settings on a public/private channel and confirm the Smoke Test tab appears
• Click the tab and verify it renders the channel display name, name, and ID
• Type into the input to mark the tab dirty, then try switching tabs to confirm the unsaved-change warning
• Verify the plugin starts cleanly even if GetTeams() returns an error (check server logs for warn-level messages instead of crashes)

🤖 Generated with Claude Code

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 56223aa7-d4fd-4ab3-ba40-3515d255f266

📥 Commits

Reviewing files that changed from the base of the PR and between 2b819ee and 0728245.

📒 Files selected for processing (1)

• webapp/src/plugin.jsx

🚧 Files skipped from review as they are similar to previous changes (1)

• webapp/src/plugin.jsx

---

📝 Walkthrough

Walkthrough

Server activation/deactivation and configuration now log warnings and continue on team/query or message-post failures instead of returning errors. A new React component, ChannelSettingsSmokeTest, was added and registered as a Channel Settings tab in the plugin.

Changes

Cohort / File(s)	Summary
Server hook activation / deactivation server/activate_hooks.go	OnActivate and OnDeactivate: failures querying teams now log a warning and skip posting messages instead of returning an error; teams without demoChannelID are skipped with a warning; posting failures are logged and processing continues.
Server configuration / demo setup server/configuration.go	Demo user/channel setup: failures to fetch teams now log warnings and skip related actions instead of returning errors; demo channel setup may return an empty map with nil error to allow graceful skipping.
Frontend smoke test component webapp/src/components/channel_settings_smoke_test.jsx	Adds default-export ChannelSettingsSmokeTest React component showing basic channel fields, a text input to simulate unsaved changes (calls setAreThereUnsavedChanges), save/reset handlers, optional registerSaveBarHandlers integration, and PropTypes.
Plugin registration webapp/src/plugin.jsx	Imports ChannelSettingsSmokeTest and conditionally registers it as a Channel Settings tab via registry.registerChannelSettingsTab?.(...) with uiName: 'Demo Plugin', component, and icon.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Add channel settings tab demo' clearly and concisely summarizes the main change—registering a new Channel Settings tab component and smoke-test feature.
Description check	✅ Passed	The description is well-related to the changeset, detailing the registration of the ChannelSettingsTab pluggable, the new component, and error-handling improvements for GetTeams() calls.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch channel-settings-pluggable

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

🧹 Nitpick comments (1)

webapp/src/components/channel_settings_smoke_test.jsx (1)

17-24: Consider defensive access for channel properties.

While channel is marked as required in PropTypes, accessing nested properties without defensive checks could cause runtime errors if the channel object has an unexpected shape. For a smoke test component this is likely acceptable, but consider using optional chaining for robustness.

♻️ Optional defensive access

             <div style={{marginTop: '12px'}}>
-                <strong>{'Display Name: '}</strong>{channel.display_name}
+                <strong>{'Display Name: '}</strong>{channel?.display_name}
             </div>
             <div style={{marginTop: '4px'}}>
-                <strong>{'Channel Name: '}</strong>{channel.name}
+                <strong>{'Channel Name: '}</strong>{channel?.name}
             </div>
             <div style={{marginTop: '4px'}}>
-                <strong>{'Channel ID: '}</strong>{channel.id}
+                <strong>{'Channel ID: '}</strong>{channel?.id}
             </div>

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@webapp/src/components/channel_settings_smoke_test.jsx` around lines 17 - 24,
Accessing channel.display_name, channel.name and channel.id without defensive
checks can throw if channel has an unexpected shape; update the JSX to use
optional chaining and sensible fallbacks (e.g. channel?.display_name ?? '' ,
channel?.name ?? '' , channel?.id ?? '') so missing properties render safely.
Locate the render usage of channel.display_name / channel.name / channel.id in
the channel settings smoke test component and replace direct property access
with the optional-chaining + fallback pattern to make the component robust.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@webapp/src/components/channel_settings_smoke_test.jsx`:
- Around line 17-24: Accessing channel.display_name, channel.name and channel.id
without defensive checks can throw if channel has an unexpected shape; update
the JSX to use optional chaining and sensible fallbacks (e.g.
channel?.display_name ?? '' , channel?.name ?? '' , channel?.id ?? '') so
missing properties render safely. Locate the render usage of
channel.display_name / channel.name / channel.id in the channel settings smoke
test component and replace direct property access with the optional-chaining +
fallback pattern to make the component robust.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 6ff8b33f-4acf-4e51-a81e-8586416deed2

📥 Commits

Reviewing files that changed from the base of the PR and between 9c80775 and b82d856.

📒 Files selected for processing (4)

• server/activate_hooks.go
• server/configuration.go
• webapp/src/components/channel_settings_smoke_test.jsx
• webapp/src/plugin.jsx

[hanzei]

I'm not sure I agree with the non-fatal changes

[hanzei]

It's strange that GetTeams fails. I wonder if we should still fail loudly as that makes things easier for QA to debug.

[hanzei]

I would love to see a typescript file. not a blocker