fix: Add protocol validation to KiotaRequestAdapterHook

[Fury0508]

Description

Fixes protocol validation bug in KiotaRequestAdapterHook that caused PowerBIDatasetRefreshOperator to fail with httpx.UnsupportedProtocol: Request URL is missing an 'http://' or 'https://' protocol error.

Root Cause

The hook had two bugs introduced in PR #45006:

1. Logic bug in get_host() method (line 238): Used or instead of tuple check

   # BROKEN - always evaluates to True for URLs with https://
   if not self.host.startswith("http://") or not self.host.startswith("https://"):
       return f"{connection.schema}://{self.host}"
   # Result: "https://https://api.powerbi.com" ❌

2. Missing protocol validation: __init__ set self.host directly without ensuring protocol prefix

Changes

• Added _ensure_protocol() method to validate and add protocol prefix when missing
• Fixed logic bug in get_host() - changed or to proper tuple check with startswith(("http://", "https://"))
• Added safety fallback (schema or "https") when connection.schema is None
• Added comprehensive test class TestKiotaRequestAdapterHookProtocol with 10 test cases covering all protocol scenarios

Testing

• All 10 new tests pass
• Existing msgraph tests continue to pass
• Verified fix resolves the exact error scenario from issue Upgrade to airflow 3.1.6 breaks PowerBIDatasetRefreshOperator #61081

closes: #61081

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: Claude (Anthropic) following the guidelines

AI Assistance Details:

• Used to understand root cause location by analyzing the codebase and error trace
• Used to write comprehensive test code (TestKiotaRequestAdapterHookProtocol class with 10 test cases)
• Used to suggest fail-safe options
• Final implementation and code review done by human contributor

---

Checklist:

• Code changes are covered with tests
• All tests pass locally
• Pre-commit checks pass (prek run --all-files)
• Follows commit message guidelines

[dabla]

Good catch, thanks for the PR, some small changes and we're good.

[Fury0508]

All feedback addressed! Thanks @henry3260 , @dabla

Changes made:

• Removed redundant if host else None check in __init__ (DRY principle)
• Updated get_host() to use _ensure_protocol(self.host, schema) instead of duplicating logic
• Fixed _ensure_protocol to return None for empty strings (not "")

All 10 tests passing. Ready for review!

[Fury0508]

@henry3260, @dabla Thanks for the review! I've addressed your feedback:

• Updated _ensure_protocol parameter to accept str | None
• Changed get_host return type to str (never returns None due to fallback logic)
• Used cast(str, ...) for type narrowing where needed

All tests pass and mypy checks pass now. Ready for another look when you have time!

[Fury0508]

Hi @dabla ,
Thanks for pointing that out! I’ve refactored get_host() to delegate protocol handling entirely to _ensure_protocol(), removing the duplicate startswith check and keeping things DRY. Changes are pushed 👍

[dabla]

Thx @Fury0508, nice work!