DocumentNavigator TDD Test Runner

This test suite follows Test-Driven Development methodology to implement a Substack-style floating document navigation widget. The tests define the expected behavior before implementation begins.

Test Coverage:

✅ Widget class structure and inheritance
✅ Configuration and initialization
✅ DOM rendering and UI elements
✅ Heading extraction and hierarchy building
✅ Navigation functionality and smooth scrolling
✅ Expand/collapse behavior
✅ Scroll spy and active section detection
✅ Responsive behavior and auto-hide
✅ Keyboard navigation support
✅ Event emission and user interaction
✅ Edge cases and error handling

📋 DocumentNavigator Widget TDD Test Suite

Test Chapter 1

Section 1.1

Subsection 1.1.1

Section 1.2

Test Chapter 2