ENH: drop dependency on colorama on Windows

Simply enable ANSI escape sequences processing on the Windows console.
This works only on Windows 10 and later, and colorama does the same
thing when it can.

Author: dnicolodi

mesonpy/__init__.py

@@ -156,8 +156,8 @@ def strip(string: str) -> str:
 
 
 @functools.lru_cache()
-def _use_ansi_colors() -> bool:
-    """Determine whether logging should use ANSI color escapes."""
+def _use_ansi_escapes() -> bool:
+    """Determine whether logging should use ANSI escapes."""
 
     # We print log messages and error messages that may contain file
     # names containing characters that cannot be represented in the
@@ -167,19 +167,17 @@ def _use_ansi_colors() -> bool:
 
     if 'NO_COLOR' in os.environ:
         return False
+
     if 'FORCE_COLOR' in os.environ or sys.stdout.isatty() and os.environ.get('TERM') != 'dumb':
-        try:
-            import colorama
-        except ModuleNotFoundError:
-            pass
-        else:
-            colorama.init()
+        if sys.platform == 'win32' and not os.environ.get('ANSICON'):
+            return mesonpy._util.setup_windows_console()
         return True
+
     return False
 
 
 def _log(string: str , **kwargs: Any) -> None:
-    if not _use_ansi_colors():
+    if not _use_ansi_escapes():
         string = style.strip(string)
     print(string, **kwargs)
 

mesonpy/_util.py

@@ -71,3 +71,23 @@ def update(self, description: str) -> None:
     def __exit__(self, exc_type: Any, exc_value: Any, exc_tb: Any) -> None:
         if sys.stdout.isatty():
             print()
+
+
+def setup_windows_console() -> bool:
+    from ctypes import byref, windll  # type: ignore
+    from ctypes.wintypes import DWORD
+
+    STD_OUTPUT_HANDLE = -11
+    ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x04
+
+    kernel = windll.kernel32
+    stdout = kernel.GetStdHandle(STD_OUTPUT_HANDLE)
+    mode = DWORD()
+
+    if not kernel.GetConsoleMode(stdout, byref(mode)):
+        return False
+
+    if not kernel.SetConsoleMode(stdout, mode.value | ENABLE_VIRTUAL_TERMINAL_PROCESSING):
+        return False
+
+    return True

pyproject.toml

@@ -32,7 +32,6 @@ classifiers = [
 ]
 
 dependencies = [
-  'colorama; os_name == "nt"',
   'meson >= 0.63.3; python_version < "3.12"',
   'meson >= 1.2.3; python_version >= "3.12"',
   'pyproject-metadata >= 0.7.1',

tests/test_output.py

@@ -7,22 +7,20 @@
 import mesonpy
 
 
-@pytest.mark.parametrize(
-    ('tty', 'env', 'colors'),
-    [
-        (False, {}, False),
-        (True, {}, True),
-        (False, {'NO_COLOR': ''}, False),
-        (True, {'NO_COLOR': ''}, False),
-        (False, {'FORCE_COLOR': ''}, True),
-        (True, {'FORCE_COLOR': ''}, True),
-        (True, {'FORCE_COLOR': '', 'NO_COLOR': ''}, False),
-        (True, {'TERM': ''}, True),
-        (True, {'TERM': 'dumb'}, False),
-    ],
-)
+@pytest.mark.parametrize(('tty', 'env', 'colors'), [
+    (False, {}, False),
+    (True, {}, True),
+    (False, {'NO_COLOR': ''}, False),
+    (True, {'NO_COLOR': ''}, False),
+    (False, {'FORCE_COLOR': ''}, True),
+    (True, {'FORCE_COLOR': ''}, True),
+    (True, {'FORCE_COLOR': '', 'NO_COLOR': ''}, False),
+    (True, {'TERM': ''}, True),
+    (True, {'TERM': 'dumb'}, False),
+])
 def test_use_ansi_colors(mocker, monkeypatch, tty, env, colors):
     mocker.patch('sys.stdout.isatty', return_value=tty)
+    mocker.patch('mesonpy._util.setup_windows_console', return_value=True)
     monkeypatch.delenv('NO_COLOR', raising=False)
     monkeypatch.delenv('FORCE_COLOR', raising=False)
     for key, value in env.items():