Protect mutable allowed_context_keys attribute in Selector classes

[jbouwh]

Proposed change

Protect mutable allowed_context_keys attribute in Selector based classes

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

• I understand the code I am submitting and can explain how it works.
• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.
• Any generated code has been carefully reviewed for correctness and compliance with project standards.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies a diff between library versions and ideally a link to the changelog/release notes is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[Copilot]

🟡 Changes recommended

The base initializer clears all specialized mappings, causing valid selector contexts to fail validation.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Moves selector context-key mappings from shared class attributes to per-instance state.

Changes:

• Initializes default context keys per selector instance.
• Relocates specialized mappings into three selector constructors.

File summaries

File	Description
homeassistant/helpers/selector.py	Refactors allowed_context_keys initialization.

Review details

Suppressed comments (1)

homeassistant/helpers/selector.py:445

• Add a regression test that verifies each affected selector retains its expected allowed_context_keys and that mutating one instance does not affect another; the existing schema tests do not exercise this new behavior.

        self.allowed_context_keys = {
            # Filters the available attributes based on the selected entity
            "filter_entity": {"entity"}
        }

• Files reviewed: 1/1 changed files
• Comments generated: 1
• Review effort level: Balanced

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[Copilot]

🟡 Changes recommended

The new isolation behavior lacks regression coverage.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 1
• Review effort level: Balanced

[Copilot]

🟢 Approval recommended

The implementation is correct; the only feedback concerns non-blocking test naming clarity.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Balanced

[Copilot]

🟡 Changes recommended

The test permanently pollutes the process-wide selector registry with a fake entry.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Balanced

[Copilot]

🟢 Approval recommended

The focused implementation preserves existing behavior while covering the shared-mutable-state regression.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0 new
• Review effort level: Balanced

[EetuPelkonen]

Copilot has the order backwards: all three constructors call super().init() before assigning, so nothing gets wiped. I applied this and hassfest is 0 invalid over 1515 integrations, test_selector 234 passed. The other three comments are stale.

[jbouwh]

Copilot has the order backwards: all three constructors call super().init() before assigning, so nothing gets wiped. I applied this and hassfest is 0 invalid over 1515 integrations, test_selector 234 passed. The other three comments are stale.

The issue that is solved here is the previous initialization of a mutable object. As it might be set in the subclass this mifht cause issues when a subclass changes the property.

[MartinHjelmare]

Thanks!