test: add node:test coverage for section colors, render, click/wheel seek

[OmikronApex]

Twenty-first repo from the org test-coverage audit. screen.js has no top-level wrapping IIFE for its function declarations — only the side-effect block (5Hz poller + playSong/showScreen wrapping) at the tail is wrapped. The module.exports hook wraps that tail block in an else branch instead of a bare return, since a live setInterval handle would otherwise keep the Node test process alive after the file loads.

10 tests against small hand-rolled fake bar/audio elements (no jsdom):

• _smGetColor: substring + case-insensitive section-name matching, default fallback
• _smFmt: m:ss formatting with zero-padded seconds
• _smRender: one block per section + a position marker, correct left%/width% math, numeric-suffix stripping + capitalization on labels
• _smOnClick: seeks to the clicked fraction immediately when paused, pause→seek→resume dance while playing
• _smOnWheel: fine-grained (0.1s) delta with Ctrl, full-second delta without, clamps to [0, duration]
• Both handlers no-op when duration is unknown (song not yet loaded)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Improved screen interactions for seeking and playback controls, including more precise wheel-based seeking and correct pause/resume behavior while scrubbing.
  • Fixed section labeling and color matching so display names are cleaner and section highlights are more consistent.
  • Added safer handling for empty or zero-length audio to prevent unintended actions.

• Tests

  • Expanded automated coverage for rendering, formatting, section matching, and click/wheel seeking behavior.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: dcfe1b10-a6c0-4202-82ee-e147a5ef5b36

📥 Commits

Reviewing files that changed from the base of the PR and between 1a62dec and db830cc.

📒 Files selected for processing (2)

• screen.js
• tests/screen.test.js

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📝 Walkthrough

Walkthrough

This PR adds a CommonJS export branch to screen.js, exposing internal section-map helper functions and state accessors for testing, while preserving existing browser IIFE behavior. A new test suite validates color lookup, formatting, rendering, and click/wheel seeking logic.

Changes

Section-map Test Exposure

Layer / File(s)	Summary
CommonJS export branch screen.js	Adds a Node-only branch exporting _smGetColor, _smFmt, _smCreate, _smRemove, _smUpdate, _smRender, _smOnClick, _smOnWheel, _getState(), and _setState(next); wraps existing browser side-effect code in an else branch.
Helper test suite tests/screen.test.js	Adds tests validating section-color matching, time formatting, HTML rendering with markers, label normalization, click/wheel seeking (including ctrlKey fine-grained delta and duration=0 no-ops), and pause/seek/resume behavior during playback.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: adding node:test coverage for screen.js behaviors.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ 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 chore/add-basic-tests

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