Fix bugs across component, layout, navigator and async content

[gmpassos]

Audit of the library for bugs, with a fix and a regression test for each finding.

Bugs fixed

UIComponent

• _callOnChildRendered called onChildRendered(this), so every subscriber received the parent instead of the rendered child.
• _parseOnEventKeyPress did keypress.split(':')[1]: an onEventKeyPress attribute without a : threw a RangeError that propagated to toContentElements, which swallowed it and returned an empty list — silently losing the whole render.
• focusField searched the text input in the component itself instead of in the resolved field component.
• getFieldsExtended sorted with a is UIComponent, where a is a MapEntry (always false). The actual conflict resolution happens in getFieldsComponentsMap, which used Map.fromEntries (last wins), letting a plain element overwrite an UIField component with the same field name. The preference was moved there and the redundant sort removed.
• appendStyle: ensures the previous declarations are terminated before appending (hardening — Chrome's CSSOM already serializes with a trailing ;).

UIAsyncContent

• _ensureElementForDOM had a dangling div; statement instead of return div;, so an HTML content with multiple root nodes returned the raw String instead of the built element.

UILayout

• _getElementIndexByID built the invalid CSS selector # for an element without an id, throwing a SyntaxError. This broke any evaluated uiLayout command (e.g. x(10px)) on elements without an id. Found by the new tests.
• _parseValuePx used int.parse, throwing a FormatException on fractional values (e.g. 4.5px); it is now parsed as a num and ignored when not a plain px value (e.g. calc(...)).
• _valueXY returned '0 px' (invalid CSS, note the space).
• The window resize listener was registered by every UILayout instance, because _registeredWindow was not static.
• _configure: removed a no-op split() over a regex passed as a literal String.
• _getElementIndex/_getElementIndexByID are now null-safe for detached elements.

UINavigator

• navigateOnClick did setAttribute(..., route!) and threw on a null route; it now clears a previously registered route and returns null.
• _navigateTo: the "navigable not found" retry dropped the fromURL flag, pushing a duplicated entry in the browser history for URL-driven navigations.

Others

• UIElementExtension.resolveUIComponent force-unwrapped UIRoot.getInstance().
• UIEventHandler.trackAllRegisteredEventListeners used isElement where isEmpty was meant.
• $uiButtonLoader: button-style was only emitted when buttonClasses was provided (and emitted empty when only buttonClasses was given); loaded-text-classes was built from buttonClasses instead of loadedTextClass; UIButtonLoader.generator now also accepts the loaded-text-classes attribute that $uiButtonLoader generates.

Tests

5 new test files with 34 tests: bones_ui_component_test.dart, bones_ui_async_content_test.dart, bones_ui_layout_test.dart, bones_ui_navigator_test.dart and bones_ui_button_test.dart.

Verified as real regression tests: stashing the lib/ changes makes 12 of them fail, one per distinct fix.

• Suite: 13 → 94 passing (47 tests × dart2js + dart2wasm, plus the VM version test).
• dart analyze: no issues. dart format: no changes.

Note

The version bump to 3.0.19 (pubspec.yaml + BonesUI.version + CHANGELOG.md) is included in this branch; drop it if you prefer to release separately via bump.sh.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 87.03704% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.84%. Comparing base (8459262) to head (26e31e6).

Files with missing lines	Patch %	Lines
lib/src/bones_ui_layout.dart	70.00%	3 Missing ⚠️
lib/src/bones_ui_component.dart	88.88%	2 Missing ⚠️
lib/src/component/button.dart	50.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master      #45       +/-   ##
===========================================
+ Coverage   40.16%   60.84%   +20.67%     
===========================================
  Files          24       25        +1     
  Lines        3946     4587      +641     
===========================================
+ Hits         1585     2791     +1206     
+ Misses       2361     1796      -565     

Flag	Coverage Δ
unittests	60.84% <87.03%> (+20.67%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.