Fixed prefab instantiation with Configurable Enter Play Mode

[Nezz]

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• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• No compiler errors or warnings

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• Bugfix
• Feature
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• Refactoring (no functional changes, no api changes)
• Build related changes
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Issue Number

Issue Number: N/A

Create or search an issue here: Extenject/Issues

What is the current behavior?

We encountered an issue where ZenjectIntegrationTestFixture destroys MainThreadDispatcher before ProjectContext, which leads to test failures when MainThreadDispatcher is used when disposing the context. This happens when Unity is configured to enter/exit play mode without a domain reload.

Under the hood a magical _disabledIndestructibleGameObject is used in the Unity Editor to instantiate prefabs in an inactive state. ProjectContext is one such prefab. The reference to this magical GameObject is stored in a static variable:

static GameObject _disabledIndestructibleGameObject;

After exiting play mode, this GameObject reference is still alive (null check returns false). The GameObject ends up in an unloaded scene named "null". Unity will happily instantiate prefabs into this null state.

When running a test that inherits from ZenjectIntegrationTestFixture, the hierarchy of the DontDestroyOnLoad scene will be incorrect, resulting in ProjectContext getting destroyed too early.

The issue is resolved when I trigger a domain reload by modifying a script, but returns when I enter and exit play mode again.

What is the new behavior?

After exiting play mode, a new GameObject will be created. ProjectContext and other prefabs will always be instantiated in the correct place (the DontDestroyOnLoad scene).

Does this introduce a breaking change?

• Yes
• No

Other information

• This change only effects the behaviour in the Unity Editor.

On which Unity version has this been tested?

• 2020.3 LTS
• 2020.2
• 2020.1
• 2019.4 LTS
• 2019.3
• 2019.2
• 2019.1
• 2018.4 LTS

Scripting backend:

• Mono
• IL2CPP

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