# Objective
While tackling https://github.com/bevyengine/bevy/issues/7386, I noticed
a few nits / frustrations with the existing testing infrastructure.
Rather than mixing those changes in with much more challenging to review
changes to reduce ambiguities, I've split this work into its own PR.
## Solution
Substantially simplify the `ambiguity_detection` test code, and reduce
the verbosity of logging.
## Testing
When run locally, the test functions as expected, with somewhat cleaner
logging.
---------
Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
# Objective
Fixes https://github.com/bevyengine/bevy/issues/14277.
May also fix https://github.com/bevyengine/bevy/issues/14255, needs
verification.
## Solution
Explicitly order `CameraUpdateSystem` before `UiSystem::Prepare`, so
that when the window resizes, `camera_system` will update the `Camera`'s
viewport size before `ui_layout_system` also reacts to the window resize
and tries to read the new `Camera` viewport size to set UI node sizes
accordingly.
## Testing
I tested that explicitly ordering `CameraUpdateSystem` _after_ triggers
the buggy behavior, and explicitly ordering it _before_ does not trigger
the buggy behavior or crash the app (which also demonstrates that the
system sets are ambiguous).
---
## Migration Guide
`CameraUpdateSystem` is now explicitly ordered before
`UiSystem::Prepare` instead of being ambiguous with it.
# Objective
Resolve possible ambiguity detection panic between `time_system` and
`event_update_system`.
Fixes#14524
## Solution
Sets `.ambiguous_with(event_update_system)` on `time_system`. This is
slightly new territory for me, so please treat with scepticism.
## Testing
As described in the issue, added
```
.configure_schedules(ScheduleBuildSettings {
ambiguity_detection: LogLevel::Error,
..default()
})
```
to the `time` example and ran it.
Progress towards https://github.com/bevyengine/bevy/issues/7386.
Following discussion
https://discord.com/channels/691052431525675048/1253260494538539048/1253387942311886960
This Pull Request adds an example to detect system order ambiguities,
and also asserts none exist.
A lot of schedules are ignored in ordered to have the test passing, we
should thrive to make them pass, but in other pull requests.
<details><summary>example output <b>summary</b>, without ignored
schedules</summary>
<p>
```txt
$ cargo run --example ambiguity_detection 2>&1 | grep -C 1 "pairs of syst"
2024-06-21T13:17:55.776585Z WARN bevy_ecs::schedule::schedule: Schedule First has ambiguities.
1 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
-- bevy_time::time_system (in set TimeSystem) and bevy_ecs::event::event_update_system (in set EventUpdates)
--
2024-06-21T13:17:55.782265Z WARN bevy_ecs::schedule::schedule: Schedule PreUpdate has ambiguities.
11 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
-- bevy_pbr::prepass::update_mesh_previous_global_transforms and bevy_asset::server::handle_internal_asset_events
--
2024-06-21T13:17:55.809516Z WARN bevy_ecs::schedule::schedule: Schedule PostUpdate has ambiguities.
63 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
-- bevy_ui::accessibility::image_changed and bevy_ecs::schedule::executor::apply_deferred
--
2024-06-21T13:17:55.816287Z WARN bevy_ecs::schedule::schedule: Schedule Last has ambiguities.
3 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
-- bevy_gizmos::update_gizmo_meshes<bevy_gizmos::aabb::AabbGizmoConfigGroup> (in set UpdateGizmoMeshes) and bevy_gizmos::update_gizmo_meshes<bevy_gizmos::light::LightGizmoConfigGroup> (in set UpdateGizmoMeshes)
--
2024-06-21T13:17:55.831074Z WARN bevy_ecs::schedule::schedule: Schedule ExtractSchedule has ambiguities.
296 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
-- bevy_render::extract_component::extract_components<bevy_sprite::SpriteSource> and bevy_render::render_asset::extract_render_asset<bevy_sprite::mesh2d::material::PreparedMaterial2d<bevy_sprite::mesh2d::color_material::ColorMaterial>>
```
</p>
</details>
To try locally:
```sh
CI_TESTING_CONFIG="./.github/example-run/ambiguity_detection.ron" cargo run --example ambiguity_detection --features "bevy_ci_testing,trace,trace_chrome"
```
---------
Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
