🐛 Fix authority header handling for HTTP/2

[AlexV525]

Fixes #2521

[AlexV525]

@copilot Add authority tests in the dio_test package

[Copilot]

@copilot Add authority tests in the dio_test package

Implemented in commit 34dd6c1.

I added shared authority regression coverage in dio_test (http2AuthorityTests) and wired it into plugins/http2_adapter/test/test_suite_test.dart so the HTTP/2 adapter now validates :authority includes the non-default port via a local HTTP/2 test server. No UI changes in this PR, so there is no screenshot to provide.

[AlexV525]

@copilot The test should not only targeting H2, but as a general test about header values

[Copilot]

@copilot The test should not only targeting H2, but as a general test about header values

Updated in bae1841.

I refactored this into a general shared header-value test under headers_tests (instead of a dedicated HTTP/2-only test hook). The new shared test checks non-default port preservation in host/authority header values across adapters, with VM conditional helpers for HTTP/1 and HTTP/2 paths. No UI changes here, so there’s no screenshot to provide.

[AlexV525]

@copilot Can't the test check the value directly without determining the adapter? If not, convert the test from general to the H2 adapter package only (and move under its test folder)

[Copilot]

@copilot Can't the test check the value directly without determining the adapter? If not, convert the test from general to the H2 adapter package only (and move under its test folder)

Updated in f339797.

I moved this regression test to plugins/http2_adapter/test/authority_header_test.dart and removed the adapter-branching general header test from dio_test, so it now directly validates :authority for the H2 adapter only. No UI changes in this PR.

[AlexV525]

@copilot

1. Remove unnecessary dep adding in dio_test
2. Use headers_test.dart as the filename and gracefully group tests for future addition.

[Copilot]

@copilot

1. Remove unnecessary dep adding in dio_test
2. Use headers_test.dart as the filename and gracefully group tests for future addition.

Addressed in 9cce64b.

I removed the unnecessary http2 dependency from dio_test/pubspec.yaml, renamed the H2 test file to plugins/http2_adapter/test/headers_test.dart, and wrapped it in a group('headers', ...) for future additions. No UI changes in this PR.

[AlexV525]

@copilot Format the test file

[Copilot]

@copilot Format the test file

Done in f372ff7 — I formatted plugins/http2_adapter/test/headers_test.dart.

[AlexV525]

@copilot Add changelog entry

[Copilot]

@copilot Add changelog entry

Done in b591053 — added the changelog entry under plugins/http2_adapter/CHANGELOG.md in ## Unreleased.

[github-actions]

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
plugins/http2_adapter/lib/src/connection_manager_imp.dart	🟢 82.14%	🟢 84.29%	🟢 2.15%
plugins/http2_adapter/lib/src/http2_adapter.dart	🟠 74.31%	🟢 75.69%	🟢 1.38%
Overall Coverage	🟢 88.61%	🟢 88.88%	🟢 0.27%

Minimum allowed coverage is 0%, this run produced 88.88%