Fix: Improve pipeline chaining type hints in typing.py

[gautamraj8044]

This pull request fixes Issue #3615, which relates to incorrect type hints for chained pipeline commands in the Redis Python client.

What was changed

• Updated ResponseT to support more accurate type inference.
• Added PipelineCommandsProtocol in typing.py to correctly model pipeline
  command chaining behavior.
• Ensures that IDEs and static type checkers (mypy, pyright) can infer the
  return types when pipeline commands are chained.

Why this improves the codebase

These changes enhance developer experience by:

• Providing clearer and more accurate type hints.
• Reducing confusion when chaining multiple pipeline commands.
• Improving overall code readability and type safety.

All changes are limited to type definitions and do not affect runtime behavior.

[jit-ci]

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[petyaslavova]

Hi @gautamraj8044, thank you for your contribution! We will make a review soon.

[Copilot]

Pull request overview

This pull request attempts to improve type hints for pipeline command chaining by introducing a PipelineCommandsProtocol and adding it to the ResponseT type union. The goal is to help IDEs and type checkers infer return types when chaining pipeline commands like pipe.set("a", "a1").set("b", "b1").get("a").

Changes:

• Added PipelineCommandsProtocol to the ResponseT type union
• Introduced PipelineCommandsProtocol protocol with execute_command and pipeline_execute_command methods

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[Copilot]

The PipelineCommandsProtocol type is added to the ResponseT union, but this creates a semantic issue. ResponseT is used as the return type for all Redis command methods (e.g., set(), get()). Adding PipelineCommandsProtocol to this union means that when calling redis_client.get("key"), the type checker will infer the return type could be a PipelineCommandsProtocol, which is incorrect - a regular Redis client should never return a Pipeline.

The underlying issue is that command methods are shared between Redis and Pipeline classes, but they should have different return types. A more appropriate solution would involve using TypeVars or Self types to properly model this polymorphism, rather than adding Pipeline to the general response type union.

[Copilot]

The PipelineCommandsProtocol is defined but never actually used as a type constraint anywhere in the codebase. No Pipeline class declares that it implements this protocol, nor is it used in any type annotations besides being added to the ResponseT union. For this protocol to be useful, Pipeline classes should either explicitly state they implement it, or it should be used as a type bound in relevant places. Additionally, the execute_command method in this protocol returns ResponseT, which creates a circular type reference since ResponseT now includes PipelineCommandsProtocol.

Suggested change

	def execute_command(self, *args, **options) -> ResponseT: ...
	def execute_command(self, *args, **options) -> Any: ...

[Copilot]

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