Fix cross-platform grouping tests for get_groupable_players

[Copilot]

The test_get_groupable_players_multiplatform test patched MediaPlayerEntity.async_get_groupable_players to return cross-platform results, creating a false impression that the service supports cross-platform grouping by default.

Changes

• Removed test_get_groupable_players_multiplatform from tests/components/media_player/test_init.py - this test patched the implementation and bypassed actual behavior
• Added test_get_groupable_players_multiplatform_override to demonstrate how integrations can override the method for multi-platform grouping support

Context

The default implementation filters by platform:

# homeassistant/components/media_player/__init__.py:1224
registry_entry = entity_registry.async_get(entity.entity_id)
if not registry_entry or registry_entry.platform != current_platform:
    continue

The removed test bypassed this filtering by patching the method, misrepresenting the service's behavior. The new test properly demonstrates how integrations can override async_get_groupable_players to return entities from multiple platforms when they have integration-specific logic to support cross-platform grouping.

Test Coverage

Remaining tests now accurately cover:

• test_get_groupable_players_service - Basic service functionality
• test_get_groupable_players_entity_without_feature - Feature requirement enforcement
• test_get_groupable_players_same_platform_only - Default same-platform filtering behavior
• test_get_groupable_players_multiplatform_override - Integration override capability for multi-platform grouping

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[dan-s-github]

@copilot we also need a test for multi-platform support as this is the main driver behind this service implementation

[Copilot]

@copilot we also need a test for multi-platform support as this is the main driver behind this service implementation

I'm confused by this request. The current implementation (line 1224 in init.py) filters entities by platform: if not registry_entry or registry_entry.platform != current_platform: continue. This means it only returns same-platform entities.

The test I removed was patching this method to bypass the platform filtering, which doesn't test the actual implementation.

Could you clarify:

1. Should the implementation be changed to support multi-platform grouping?
2. Or should I add a test that sets up multiple platforms and verifies the current same-platform filtering behavior?
3. What specific multi-platform scenario should the test cover?

[dan-s-github]

@copilot the default implementation will only return entities from the same platform, but other media_player entities can override this method and return entities from multiple platforms that could be grouped

[Copilot]

@copilot the default implementation will only return entities from the same platform, but other media_player entities can override this method and return entities from multiple platforms that could be...

Added test in commit 4b8f5b8 that demonstrates how integrations can override async_get_groupable_players to support multi-platform grouping. The test creates a custom entity class that overrides the method to return entities from multiple platforms (spotify, sonos, chromecast) and verifies the service properly returns those results.