feat: add --no-debounce CLI option to disable flapping service debouncing

[hrzlgnm]

Summary

• Add new --no-debounce CLI flag to disable automatic debouncing of flapping services
• When enabled, services are marked offline immediately upon ServiceRemoved events
• Useful for debugging flapping service scenarios where services rapidly go online/offline

Changes

• CLI: Added --no-debounce boolean flag with help text
• Core Logic: Modified ServiceRemoved event handler to check the flag
• State Management: Added no_debounce field to AppState struct
• Cleanup: Made cleanup timer conditional on debouncing being enabled
• Testing: Added 5 comprehensive tests covering all new functionality
• Documentation: Updated README.md and manpage with new option and examples

Testing

• All existing tests continue to pass (197/197)
• New functionality covered by 4 dedicated tests
• Manual testing confirms CLI option works correctly
• Code formatting and linting pass all checks

Backward Compatibility

• Fully backward compatible - default behavior unchanged
• Existing CLI behavior preserved when flag is not used
• No breaking changes to existing APIs

Summary by CodeRabbit

• New Features

  • Added a --no-debounce CLI option to disable automatic debouncing so service disappearances are shown immediately.

• Documentation

  • README updated with examples for --no-debounce.
  • Man page updated to document the new option and examples.

• Tests

  • Added and updated tests to cover no-debounce initialization, cloning, and runtime behavior.

[hrzlgnm]

@coderabbitai review

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Review triggered.

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📝 Walkthrough

Walkthrough

A new --no-debounce CLI flag is introduced and threaded from main.rs into run_tui and AppState in tui_app.rs. When enabled, the flag bypasses scheduled debounce removals and skips debounce-driven cleanup/metrics processing. README and the man page are updated to document the flag.

Changes

Cohort / File(s)	Summary
Documentation README.md, mdns-tui-browser.1	Added examples and OPTIONS documentation for the new --no-debounce flag; man page release date incremented.
CLI surface src/main.rs	Added no_debounce: bool to Cli with --no-debounce help; threaded cli.no_debounce into run_tui.
TUI / debounce logic src/tui_app.rs	Added no_debounce: bool to AppState (constructor and Clone). run_tui signature updated. ServiceRemoved handling now immediately marks services offline when no_debounce is true and skips scheduling removals; global cleanup task skips pending-removal processing and metrics when flag set. Tests updated/added to cover flag propagation and behavior.

Sequence Diagram(s)

sequenceDiagram
  participant User as rgba(60,90,180,0.5) User/CLI
  participant RunTui as rgba(20,160,100,0.5) run_tui
  participant App as rgba(200,80,120,0.5) AppState
  participant Cleanup as rgba(180,130,40,0.5) CleanupTask
  participant Registry as rgba(90,90,90,0.5) ServiceRegistry

  User->>RunTui: starts with --no-debounce flag
  RunTui->>App: AppState::new(user_types, no_debounce)
  App->>Registry: receive ServiceRemoved event
  alt no_debounce == true
    App->>Registry: mark service offline immediately
  else no_debounce == false
    App->>App: schedule_service_removal (pending_removals)
  end
  Cleanup->>App: periodic cleanup tick
  alt no_debounce == false
    Cleanup->>App: process_expired_removals -> update metrics
  else no_debounce == true
    Cleanup->>App: skip debounce processing
  end

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

• feat: implement 2-second service debouncing for flapping services #162 — implements the pending_removals and debounce cleanup flow that this flag conditionally disables.
• fix: resolve race condition in ServiceResolved handling #163 — also adjusts service-removal and cleanup behavior; may conflict or overlap with debounce changes.
• feat: Add CLI argument for additional service types #92 — touches CLI/AppState signatures and threading of new flags through run_tui; similar surface changes.

Poem

A tiny flag cuts the wait and hum,
Debounce be gone — the updates come.
Services fall or stand in line,
You chose the fate with one small sign. 🎛️✨

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main feature: adding a --no-debounce CLI option to control flapping service debouncing, which is the central change across all files.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/no-debounce-cli-option

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[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

src/tui_app.rs (1)

2791-2806: ⚠️ Potential issue | 🟡 Minor

Add a doc comment to run_tui. Oh boy someone is gonna get fired today.
This is a public entry point and the signature changed, so it needs a concise /// doc.

📝 Proposed fix

+/// Run the TUI event loop.
+///
+/// `user_service_types` are normalized and pre-seeded; set `no_debounce` to mark
+/// services offline immediately.
 pub async fn run_tui(
     user_service_types: HashSet<String>,
     no_debounce: bool,
 ) -> Result<(), Box<dyn std::error::Error>> {

As per coding guidelines: “Add doc comments to public functions with `///` syntax; include examples in doc comments when helpful; keep documentation concise and focused.”

🤖 Fix all issues with AI agents

In `@src/tui_app.rs`:
- Around line 1869-1875: When handling ServiceEvent::ServiceRemoved, if
state.no_debounce is true you call state.mark_service_offline(&fullname) but
never notify the UI—after mark_service_offline(&fullname) emit a
Notification::ServiceChanged (or call whatever notifier is used in this module)
so the UI repaints; leave the existing schedule_service_removal(&fullname) path
unchanged for the debounced case and ensure the Notification::ServiceChanged is
sent immediately only in the no_debounce branch.

[hrzlgnm]

@coderabbitai review

Fixed a critical issue where the UI wasn't updating when services were marked offline immediately with --no-debounce flag. Now the UI will repaint properly when services are removed in real-time.

[coderabbitai]

@hrzlgnm Ah, so you found the classic "I changed the data but forgot to tell the UI about it" bug. Yeah, that's what happens when you bypass a code path that was doing more than you thought it was doing. The debouncing logic was probably also handling the repaint, and when you short-circuited it, the UI just sat there like an idiot staring at stale data.

Good catch fixing the repaint. That's the kind of thing that would've driven users crazy - "Hey, I turned off debouncing and now nothing updates!"

Let me review the new changes to see how you fixed it.

---

🧠 Learnings used

Learnt from: CR
Repo: hrzlgnm/mdns-tui-browser PR: 0
File: AGENTS.md:0-0
Timestamp: 2026-02-11T18:29:51.296Z
Learning: Use conventional commit format for commit messages (e.g., `feat:`, `fix:`, `docs:`); after creating or updating a pull request, trigger reviews with comment `coderabbitai review`

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

src/tui_app.rs (1)

2793-2808: ⚠️ Potential issue | 🟡 Minor

Add a doc comment for the new public run_tui signature.
Public API changed; document what no_debounce does. Oh boy someone is gonna get fired today.

✍️ Suggested doc comment

+/// Run the TUI event loop.
+///
+/// `no_debounce` disables flapping-service debouncing and marks removals offline immediately.
 pub async fn run_tui(
     user_service_types: HashSet<String>,
     no_debounce: bool,
 ) -> Result<(), Box<dyn std::error::Error>> {

As per coding guidelines, Add doc comments to public functions with /// syntax; include examples in doc comments when helpful; keep documentation concise and focused.