fix: support wider range of verbosity settings on other build backends (#2339)

* fix: support wider range of verbosity settings on other build backends

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Apply suggestions from code review

Co-authored-by: Matthieu Darbois <mayeut@users.noreply.github.com>

* refactor: address review comments

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Matthieu Darbois <mayeut@users.noreply.github.com>

unit_test/options_test.py

@@ -1,12 +1,16 @@
 import os
 import platform as platform_module
 import textwrap
+import unittest.mock
 from pathlib import Path
+from typing import Literal
 
 import pytest
 
 from cibuildwheel import errors
 from cibuildwheel.bashlex_eval import local_environment_executor
+from cibuildwheel.frontend import BuildFrontendConfig, get_build_frontend_extra_flags
+from cibuildwheel.logger import Logger
 from cibuildwheel.options import (
     CommandLineArguments,
     Options,
@@ -570,3 +574,47 @@ def test_deprecated_image(
         assert f"{resolved_image!r}" in captured.err
     else:
         assert "Deprecated image" not in captured.err
+
+
+@pytest.mark.parametrize(
+    ("frontend", "verbosity", "result"),
+    [
+        ("pip", 3, ["-Ca", "-Cb", "-1", "-vvv"]),
+        ("pip", 2, ["-Ca", "-Cb", "-1", "-vv"]),
+        ("pip", -1, ["-Ca", "-Cb", "-1", "-q"]),
+        ("build", 0, ["-Ca", "-Cb", "-1"]),
+        ("build", 1, ["-Ca", "-Cb", "-1"]),
+        ("build", 2, ["-Ca", "-Cb", "-1", "-v"]),
+        ("build", 3, ["-Ca", "-Cb", "-1", "-vv"]),
+        ("build[uv]", 3, ["-Ca", "-Cb", "-1", "-vv"]),
+    ],
+)
+def test_get_build_frontend_extra_flags(
+    frontend: Literal["pip", "build", "build[uv]"],
+    verbosity: int,
+    result: list[str],
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    mock_warning = unittest.mock.MagicMock()
+    monkeypatch.setattr(Logger, "warning", mock_warning)
+    build_frontend = BuildFrontendConfig(frontend, ["-1"])
+    args = get_build_frontend_extra_flags(
+        build_frontend=build_frontend, verbosity_level=verbosity, config_settings="a b"
+    )
+
+    assert args == result
+    mock_warning.assert_not_called()
+
+
+@pytest.mark.parametrize("frontend", ["build", "build[uv]"])
+def test_get_build_frontend_extra_flags_warning(
+    frontend: Literal["build", "build[uv]"], monkeypatch: pytest.MonkeyPatch
+) -> None:
+    mock_warning = unittest.mock.MagicMock()
+    monkeypatch.setattr(Logger, "warning", mock_warning)
+    build_frontend = BuildFrontendConfig(frontend, ["-1"])
+    args = get_build_frontend_extra_flags(
+        build_frontend=build_frontend, verbosity_level=-1, config_settings="a b"
+    )
+    assert args == ["-Ca", "-Cb", "-1"]
+    mock_warning.assert_called_once()