Kishan Rathore 130808cb68
Add TestWidgetsApp utility and refactor widget tests to use WidgetsApp (#180456)
This PR introduces a TestWidgetsApp utility class that provides a
minimal WidgetsApp wrapper for widget tests, replacing direct usage of
Directionality widgets.

part of: #177415 

## Changes
- test_widgets_app.dart - A reusable TestWidgetsApp widget that wraps
WidgetsApp with a builder pattern, providing Directionality, MediaQuery,
and other app-level widgets that WidgetsApp provides.
- gesture_detector_test.dart - Replaced 9 Directionality usages
- mouse_region_test.dart - Replaced 13 Directionality usages
- opacity_test.dart - Replaced 2 Directionality usages
- slivers_evil_test.dart - Replaced 3 Directionality usages and removed
redundant MediaQuery wrappers

## Note
- This PR updates golden test baselines for opacity_test.dart.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [ ] All existing and new tests are passing.
2026-01-29 17:29:01 +00:00
..