Centralize mono/nuget platform skip predicate in conftest.py

[Copilot]

The skip predicate for macOS ARM runners (macos-15, macos-26) was duplicated across four C# integration test files with identical logic and comments.

Changes

• Created csharp/ql/integration-tests/posix/conftest.py with a shared _supports_mono_nuget() helper function
• Replaced inline skip predicates in four test files with calls to the centralized helper:
  • standalone_dependencies_no_framework/test.py
  • standalone_dependencies_nuget/test.py
  • standalone_dependencies_nuget with_space/test.py
  • standalone_dependencies_nuget_no_sources/test.py

Before:

import runs_on
import pytest

# Skipping the test on the ARM runners, macos-15 and macos-26, as we're running
# into trouble with Mono and nuget.
@pytest.mark.only_if(
    runs_on.linux
    or (runs_on.macos and runs_on.x86_64
        and not runs_on.macos_15 and not runs_on.macos_26)
)
def test(codeql, csharp):
    ...

After:

import pytest
from conftest import _supports_mono_nuget

@pytest.mark.only_if(_supports_mono_nuget())
def test(codeql, csharp):
    ...

This ensures the excluded macOS version list stays consistent across all affected tests.

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[Copilot]

Pull request overview

Centralizes a repeated pytest skip predicate for Mono/nuget support into a shared helper to keep macOS ARM runner exclusions consistent across C# integration tests.

Changes:

• Added csharp/ql/integration-tests/posix/conftest.py with _supports_mono_nuget() helper.
• Updated four tests to use the shared helper instead of inline predicates.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
csharp/ql/integration-tests/posix/conftest.py	Introduces shared platform-support predicate for Mono/nuget.
csharp/ql/integration-tests/posix/standalone_dependencies_no_framework/test.py	Uses shared predicate for conditional test execution.
csharp/ql/integration-tests/posix/standalone_dependencies_nuget/test.py	Uses shared predicate for conditional test execution.
csharp/ql/integration-tests/posix/standalone_dependencies_nuget with_space/test.py	Uses shared predicate for conditional test execution.
csharp/ql/integration-tests/posix/standalone_dependencies_nuget_no_sources/test.py	Uses shared predicate for conditional test execution.

[Copilot]

Importing from conftest.py is discouraged in pytest because conftest is a special discovery file (loaded by path), and importing it as a module can lead to confusing behavior (e.g., it not being importable in some runners, or being loaded inconsistently). Consider moving _supports_mono_nuget() to a regular helper module (e.g., mono_nuget_support.py / platform_support.py) and importing from that module instead.

Suggested change

	from conftest import _supports_mono_nuget
	import shutil
	def _supports_mono_nuget() -> bool:
	"""
	Return True if the current environment appears to support running C# via
	Mono and NuGet. This checks for the presence of the corresponding
	executables on PATH.
	"""
	return shutil.which("mono") is not None and shutil.which("nuget") is not None

[Copilot]

The leading underscore implies a private helper, but it’s imported and used by multiple test modules. Consider renaming it to supports_mono_nuget (no leading underscore) to reflect its intended shared usage.

[Copilot]

The docstring contains a whitespace-only line (line 7). Consider removing the trailing spaces/empty whitespace line to satisfy common linters and keep formatting clean.

Suggested change