Improved InputCheckBox Test Coverage in Blazor

[PreethikaSelvam]

Description

This PR significantly enhances the test coverage of the Blazor InputCheckbox component by adding 20 new test cases, increasing the total test count to 23 with 100% pass rate.

Key Improvements:

• Expanded coverage across all critical areas:
• Rendering (type, id, name, value)
• Checked/unchecked state behavior
• Two-way binding and event handling (onchange)
• ValueChanged callback validation
• CSS class updates (valid, invalid, modified states)
• EditContext integration and field change tracking
• Attribute propagation and override scenarios
• Edge cases (no EditContext, unchanged values)

Testing Enhancements

• Added strict assertions to ensure regressions are caught
• Verified event binding via handler ID checks
• Ensured EditContext notifications and validation states are correctly triggered
• Improved robustness by replacing risky assertions with safer patterns

Impact

• Eliminates previous coverage gaps (binding, validation, CSS, events)
• Strengthens regression protection for checkbox behavior
• Aligns with unit testing best practices for component-level validation

PR Checklist

• Small and focused — Only test improvements for InputCheckbox
• Tests added — 20 new test cases added
• Code style matches — Follows existing patterns
• Local build passes
• Local tests pass (23/23)
• No breaking changes
• Issue linked (if applicable) — Not applicable
• Public API updates — Not applicable
• XML documentation — Not applicable

[dotnet-policy-service]

Thanks for your PR, @PreethikaSelvam. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[PreethikaSelvam]

@dotnet-policy-service agree company="Syncfusion, Inc."