From c6ca5e554e6aa1989fe02ef4017ae535d29a6e8f Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Thu, 21 Sep 2023 21:53:57 +0300
Subject: [PATCH 01/16] Create `_is_env_set_and_non_empty`

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
---
 pylint/lint/utils.py     |  6 ++++++
 tests/lint/test_utils.py | 35 ++++++++++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/pylint/lint/utils.py b/pylint/lint/utils.py
index c5487a8c6d..f73f7248fa 100644
--- a/pylint/lint/utils.py
+++ b/pylint/lint/utils.py
@@ -5,6 +5,7 @@
 from __future__ import annotations
 
 import contextlib
+import os
 import platform
 import sys
 import traceback
@@ -133,3 +134,8 @@ def augmented_sys_path(additional_paths: Sequence[str]) -> Iterator[None]:
         yield
     finally:
         sys.path[:] = original
+
+
+def _is_env_set_and_non_empty(env_var: str) -> bool:
+    """Checks if env_var is set and non-empty."""
+    return os.environ.get(env_var) not in ["", None]
diff --git a/tests/lint/test_utils.py b/tests/lint/test_utils.py
index fa449374a9..6d11adf797 100644
--- a/tests/lint/test_utils.py
+++ b/tests/lint/test_utils.py
@@ -4,11 +4,16 @@
 
 import unittest.mock
 from pathlib import Path, PosixPath
+from typing import Any
 
 import pytest
 
 from pylint.constants import full_version
-from pylint.lint.utils import get_fatal_error_message, prepare_crash_report
+from pylint.lint.utils import (
+    _is_env_set_and_non_empty,
+    get_fatal_error_message,
+    prepare_crash_report,
+)
 from pylint.testutils._run import _Run as Run
 
 
@@ -56,3 +61,31 @@ def test_issue_template_on_fatal_errors(capsys: pytest.CaptureFixture) -> None:
     assert "Fatal error while checking" in captured.out
     assert "Please open an issue" in captured.out
     assert "Traceback" in captured.err
+
+
+@pytest.mark.parametrize(
+    "value, expected",
+    [
+        (None, False),
+        ("", False),
+        (0, True),
+        (1, True),
+        (2, True),
+        (False, True),
+        ("no", True),
+        ("off", True),
+        ("on", True),
+        (True, True),
+        ("yes", True),
+    ],
+    ids=repr,
+)
+def test_is_env_set_and_non_empty(
+    monkeypatch: pytest.MonkeyPatch, value: Any, expected: bool
+) -> None:
+    """Test the function returns True if the environment variable is set and non-empty."""
+    env_var = "TEST_VAR"
+    if value is not None:
+        monkeypatch.setenv(env_var, str(value))
+
+    assert _is_env_set_and_non_empty(env_var) == expected

From aec5efbaa3519fc85e3f5a2c55c1dbeb59cafe57 Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Thu, 21 Sep 2023 23:42:19 +0300
Subject: [PATCH 02/16] Second option for `_is_env_set_and_non_empty`

---
 pylint/lint/utils.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pylint/lint/utils.py b/pylint/lint/utils.py
index f73f7248fa..6b4cda1de8 100644
--- a/pylint/lint/utils.py
+++ b/pylint/lint/utils.py
@@ -138,4 +138,4 @@ def augmented_sys_path(additional_paths: Sequence[str]) -> Iterator[None]:
 
 def _is_env_set_and_non_empty(env_var: str) -> bool:
     """Checks if env_var is set and non-empty."""
-    return os.environ.get(env_var) not in ["", None]
+    return bool(os.environ.get(env_var))

From b5b91c19e0861dbd04b8f8f011f902f3b88551e4 Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Thu, 21 Sep 2023 23:42:04 +0300
Subject: [PATCH 03/16] Create `pylinter#_handle_force_color_no_color`

Use the `_is_env_set_and_non_empty`, and the logic decided in the issue,
to modify the reporter(s) list accordingly.

At most, one reporter should be modified - the one going to `stdout`.

Hooking before the `self.set_reporter` was deemed as the smallest incision.

For no particular reason, it was decided that
`_handle_force_color_no_color` would modify its input;
so there would be no need for re-assigning the input we want to modify anyway.

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
---
 pylint/lint/pylinter.py      | 77 +++++++++++++++++++++++++++++++++++-
 pylint/reporters/__init__.py |  4 ++
 2 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index cc4605b96a..ba3c501fc4 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -12,6 +12,7 @@
 import sys
 import tokenize
 import traceback
+import warnings
 from collections import defaultdict
 from collections.abc import Callable, Iterable, Iterator, Sequence
 from io import TextIOWrapper
@@ -48,13 +49,15 @@
     report_total_messages_stats,
 )
 from pylint.lint.utils import (
+    _is_env_set_and_non_empty,
     augmented_sys_path,
     get_fatal_error_message,
     prepare_crash_report,
 )
 from pylint.message import Message, MessageDefinition, MessageDefinitionStore
+from pylint.reporters import ReporterWarning
 from pylint.reporters.base_reporter import BaseReporter
-from pylint.reporters.text import TextReporter
+from pylint.reporters.text import ColorizedTextReporter, TextReporter
 from pylint.reporters.ureports import nodes as report_nodes
 from pylint.typing import (
     DirectoryNamespaceDict,
@@ -69,6 +72,14 @@
 
 MANAGER = astroid.MANAGER
 
+NO_COLOR = "NO_COLOR"
+FORCE_COLOR = "FORCE_COLOR"
+PY_COLORS = "PY_COLORS"
+
+WARN_FORCE_COLOR_SET = "FORCE_COLOR is set; ignoring `text` at stdout"
+WARN_NO_COLOR_SET = "NO_COLOR is set; ignoring `colorized` at stdout"
+WARN_BOTH_COLOR_SET = "Both NO_COLOR and FORCE_COLOR are set! (disabling colors)"
+
 
 class GetAstProtocol(Protocol):
     def __call__(
@@ -250,6 +261,68 @@ def _load_reporter_by_class(reporter_class: str) -> type[BaseReporter]:
 }
 
 
+def _handle_force_color_no_color(reporter: list[reporters.BaseReporter]) -> None:
+    """
+    Check ``NO_COLOR``, ``FORCE_COLOR``, ``PY_COLOR`` and modify the reporter list
+    accordingly.
+
+    Rules are presented in this table:
+    +--------------+---------------+-----------------+------------------------------------------------------------+
+    | `NO_COLOR`   | `FORCE_COLOR` | `output-format` | Behavior                                                   |
+    +==============+===============+=================+============================================================+
+    | `bool: True` | `bool: True`  | colorized       | not colorized + warnings (override + inconsistent env var) |
+    | `bool: True` | `bool: True`  | /               | not colorized + warnings (inconsistent env var)            |
+    | unset        | `bool: True`  | colorized       | colorized                                                  |
+    | unset        | `bool: True`  | /               | colorized + warnings (override)                            |
+    | `bool: True` | unset         | colorized       | not colorized + warnings (override)                        |
+    | `bool: True` | unset         | /               | not colorized                                              |
+    | unset        | unset         | colorized       | colorized                                                  |
+    | unset        | unset         | /               | not colorized                                              |
+    +--------------+---------------+-----------------+------------------------------------------------------------+
+    """
+    no_color = _is_env_set_and_non_empty(NO_COLOR)
+    force_color = _is_env_set_and_non_empty(FORCE_COLOR) or _is_env_set_and_non_empty(
+        PY_COLORS
+    )
+
+    if no_color and force_color:
+        warnings.warn(
+            WARN_BOTH_COLOR_SET,
+            ReporterWarning,
+            stacklevel=2,
+        )
+        force_color = False
+
+    if no_color:
+        for idx, rep in enumerate(list(reporter)):
+            if not isinstance(rep, ColorizedTextReporter):
+                continue
+
+            if rep.out.buffer is sys.stdout.buffer:
+                warnings.warn(
+                    WARN_NO_COLOR_SET,
+                    ReporterWarning,
+                    stacklevel=2,
+                )
+                reporter.pop(idx)
+                reporter.append(TextReporter())
+
+    elif force_color:
+        for idx, rep in enumerate(list(reporter)):
+            # pylint: disable=unidiomatic-typecheck # Want explicit type check
+            if type(rep) is not TextReporter:
+                continue
+
+            if rep.out.buffer is sys.stdout.buffer:
+                warnings.warn(
+                    WARN_FORCE_COLOR_SET,
+                    ReporterWarning,
+                    stacklevel=2,
+                )
+                reporter.pop(idx)
+                reporter.append(ColorizedTextReporter())
+
+
 # pylint: disable=too-many-instance-attributes,too-many-public-methods
 class PyLinter(
     _ArgumentsManager,
@@ -435,6 +508,8 @@ def _load_reporters(self, reporter_names: str) -> None:
             # Extend the lifetime of all opened output files
             close_output_files = stack.pop_all().close
 
+        _handle_force_color_no_color(sub_reporters)
+
         if len(sub_reporters) > 1 or output_files:
             self.set_reporter(
                 reporters.MultiReporter(
diff --git a/pylint/reporters/__init__.py b/pylint/reporters/__init__.py
index c24ea4be88..b5c4e3818c 100644
--- a/pylint/reporters/__init__.py
+++ b/pylint/reporters/__init__.py
@@ -19,6 +19,10 @@
     from pylint.lint.pylinter import PyLinter
 
 
+class ReporterWarning(Warning):
+    """Warning class for reporters."""
+
+
 def initialize(linter: PyLinter) -> None:
     """Initialize linter with reporters in this package."""
     utils.register_plugins(linter, __path__[0])

From 7e12334bea50e5aaf70ff504ae91de346b19f53f Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Fri, 29 Sep 2023 14:01:55 +0300
Subject: [PATCH 04/16] `test_handle_force_color_no_color`

---
 tests/lint/test_pylinter.py | 151 +++++++++++++++++++++++++++++++++++-
 1 file changed, 150 insertions(+), 1 deletion(-)

diff --git a/tests/lint/test_pylinter.py b/tests/lint/test_pylinter.py
index bc12455354..3f1267791b 100644
--- a/tests/lint/test_pylinter.py
+++ b/tests/lint/test_pylinter.py
@@ -2,17 +2,36 @@
 # For details: https://github.com/pylint-dev/pylint/blob/main/LICENSE
 # Copyright (c) https://github.com/pylint-dev/pylint/blob/main/CONTRIBUTORS.txt
 
+from __future__ import annotations
+
+import io
 import os
+import sys
+import warnings
 from pathlib import Path
 from typing import Any, NoReturn
 from unittest import mock
 from unittest.mock import patch
 
+import pytest
 from pytest import CaptureFixture
 
-from pylint.lint.pylinter import MANAGER, PyLinter
+from pylint.lint.pylinter import (
+    FORCE_COLOR,
+    MANAGER,
+    NO_COLOR,
+    PY_COLORS,
+    WARN_BOTH_COLOR_SET,
+    PyLinter,
+    _handle_force_color_no_color,
+)
+from pylint.reporters.text import ColorizedTextReporter, TextReporter
 from pylint.utils import FileState
 
+COLORIZED_REPORTERS = "colorized_reporters"
+TEXT_REPORTERS = "text_reporters"
+STDOUT_TEXT = "stdout"
+
 
 def raise_exception(*args: Any, **kwargs: Any) -> NoReturn:
     raise ValueError
@@ -68,3 +87,133 @@ def test_open_pylinter_prefer_stubs(linter: PyLinter) -> None:
         assert MANAGER.prefer_stubs
     finally:
         MANAGER.prefer_stubs = False
+
+
+def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
+    if metafunc.function.__name__ != test_handle_force_color_no_color.__name__:
+        return
+
+    if (
+        TEXT_REPORTERS not in metafunc.fixturenames
+        or COLORIZED_REPORTERS not in metafunc.fixturenames
+    ):
+        warnings.warn(
+            f"Missing fixture {TEXT_REPORTERS} or {COLORIZED_REPORTERS} in"
+            f" {test_handle_force_color_no_color.function.__name__}??",
+            stacklevel=2,
+        )
+        return
+
+    parameters = []
+
+    reporter_combinations = [
+        ("file", STDOUT_TEXT),
+        ("file",),
+        (STDOUT_TEXT,),
+        ("",),
+    ]
+
+    for tr in list(reporter_combinations):
+        for cr in list(reporter_combinations):
+            tr = tuple(t for t in tr if t)
+            cr = tuple(t for t in cr if t)
+
+            total_reporters = len(tr) + len(cr)
+            unique_reporters = len(set(tr + cr))
+
+            if total_reporters == 0:
+                continue
+
+            if unique_reporters != total_reporters:
+                continue
+
+            parameters.append((tuple(tr), tuple(cr)))
+
+    metafunc.parametrize(
+        f"{TEXT_REPORTERS}, {COLORIZED_REPORTERS}", parameters, ids=repr
+    )
+
+
+@pytest.mark.parametrize(
+    "no_color",
+    [True, False],
+    ids=lambda no_color: f"{no_color=}",
+)
+@pytest.mark.parametrize(
+    "py_colors",
+    [True, False],
+    ids=lambda py_colors: f"{py_colors=}",
+)
+@pytest.mark.parametrize(
+    "force_color",
+    [True, False],
+    ids=lambda force_color: f"{force_color=}",
+)
+def test_handle_force_color_no_color(
+    monkeypatch: pytest.MonkeyPatch,
+    recwarn: pytest.WarningsRecorder,
+    no_color: bool,
+    py_colors: bool,
+    force_color: bool,
+    text_reporters: tuple[str],
+    colorized_reporters: tuple[str],
+) -> None:
+    monkeypatch.setenv(NO_COLOR, "1" if no_color else "")
+    monkeypatch.setenv(FORCE_COLOR, "1" if force_color else "")
+    monkeypatch.setenv(PY_COLORS, "1" if py_colors else "")
+
+    force_color = force_color or py_colors
+
+    if STDOUT_TEXT in text_reporters or STDOUT_TEXT in colorized_reporters:
+        monkeypatch.setattr(sys, STDOUT_TEXT, io.TextIOWrapper(io.BytesIO()))
+
+    reporters = []
+    for reporter, group in (
+        (TextReporter, text_reporters),
+        (ColorizedTextReporter, colorized_reporters),
+    ):
+        for name in group:
+            if name == STDOUT_TEXT:
+                reporters.append(reporter())
+            if name == "file":
+                reporters.append(reporter(io.TextIOWrapper(io.BytesIO())))
+
+    _handle_force_color_no_color(reporters)
+
+    if no_color and force_color:
+        # Both NO_COLOR and FORCE_COLOR are set; expecting a warning.
+        both_color_warning = [
+            idx
+            for idx, w in enumerate(recwarn.list)
+            if WARN_BOTH_COLOR_SET in str(w.message)
+        ]
+        assert len(both_color_warning) == 1
+        recwarn.list.pop(both_color_warning[0])
+
+    if no_color:
+        # No ColorizedTextReporter expected to be connected to stdout.
+        assert all(
+            not isinstance(rep, ColorizedTextReporter)
+            for rep in reporters
+            if rep.out.buffer is sys.stdout.buffer
+        )
+
+        if STDOUT_TEXT in colorized_reporters:
+            assert len(recwarn.list) == 1  # expect a warning for overriding stdout
+        else:
+            assert len(recwarn.list) == 0  # no warning expected
+    elif force_color:
+        # No TextReporter expected to be connected to stdout.
+        # pylint: disable=unidiomatic-typecheck # Want explicit type check.
+        assert all(
+            type(rep) is not TextReporter
+            for rep in reporters
+            if rep.out.buffer is sys.stdout.buffer
+        )
+
+        if STDOUT_TEXT in text_reporters:
+            assert len(recwarn.list) == 1  # expect a warning for overriding stdout
+        else:
+            assert len(recwarn.list) == 0  # no warning expected
+    else:
+        assert len(recwarn.list) == 0  # no warning expected

From 7f38e761ae31d4e5ae8a392e909fe92bc3e363b5 Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Wed, 4 Oct 2023 14:19:15 +0300
Subject: [PATCH 05/16] `towncrier`: `3995.feature`

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
---
 doc/whatsnew/fragments/3995.feature | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 doc/whatsnew/fragments/3995.feature

diff --git a/doc/whatsnew/fragments/3995.feature b/doc/whatsnew/fragments/3995.feature
new file mode 100644
index 0000000000..5187567d09
--- /dev/null
+++ b/doc/whatsnew/fragments/3995.feature
@@ -0,0 +1,5 @@
+Support for ``NO_COLOR`` and ``FORCE_COLOR`` (and ``PY_COLORS``, as an alias to ``FORCE_COLOR``) environment variables has been added.
+When running `pylint`, the reporter that reports to ``stdout`` will be modified according to the requested mode.
+The order is: ``NO_COLOR`` > ``FORCE_COLOR``, ``PY_COLORS`` > ``--output=...``.
+
+Closes #3995 (https://github.com/pylint-dev/pylint/issues/3995).

From 4427cf3cdde5d2490a7498a4b9d80dfc96724fa1 Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Sat, 7 Oct 2023 23:31:15 +0300
Subject: [PATCH 06/16] Documentation for
 https://github.com/pylint-dev/pylint/issues/3995

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
---
 doc/user_guide/usage/output.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/doc/user_guide/usage/output.rst b/doc/user_guide/usage/output.rst
index 50a7fa76e4..0de49a0cb3 100644
--- a/doc/user_guide/usage/output.rst
+++ b/doc/user_guide/usage/output.rst
@@ -21,6 +21,19 @@ a colorized report to stdout at the same time:
 
   --output-format=json:somefile.json,colorized
 
+Environment Variables
+''''''''''''''''''''''''''''
+The colorization of the output can also be controlled through environment
+variables. The precedence for determining output format is as follows:
+
+1. ``NO_COLOR``
+2. ``FORCE_COLOR``, or ``PY_COLORS``
+3. ``--output-format=...``
+
+Setting ``NO_COLOR`` (to any value) will disable colorized output, while
+``FORCE_COLOR`` or ``PY_COLORS`` (to any value) will enable it, overriding
+the ``--output-format`` option if specified.
+
 
 Custom message formats
 ''''''''''''''''''''''

From 51cf8d2fcbfa852449d3208b91eca9bbbbf61729 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Sun, 12 Jan 2025 16:17:28 +0100
Subject: [PATCH 07/16] Remove `PY_COLORS`, fix spelling and don't modify in
 place

---
 custom_dict.txt                     |  1 +
 doc/user_guide/usage/output.rst     |  6 +--
 doc/whatsnew/fragments/3995.feature |  7 ++--
 pylint/lint/pylinter.py             | 63 +++++++++++++----------------
 tests/lint/test_pylinter.py         | 10 -----
 tests/lint/test_utils.py            |  9 +----
 6 files changed, 38 insertions(+), 58 deletions(-)

diff --git a/custom_dict.txt b/custom_dict.txt
index 265c7cb881..1996266e1e 100644
--- a/custom_dict.txt
+++ b/custom_dict.txt
@@ -108,6 +108,7 @@ encodings
 endswith
 enum
 enums
+env
 epilog
 epylint
 epytext
diff --git a/doc/user_guide/usage/output.rst b/doc/user_guide/usage/output.rst
index 0de49a0cb3..9de4085291 100644
--- a/doc/user_guide/usage/output.rst
+++ b/doc/user_guide/usage/output.rst
@@ -27,12 +27,12 @@ The colorization of the output can also be controlled through environment
 variables. The precedence for determining output format is as follows:
 
 1. ``NO_COLOR``
-2. ``FORCE_COLOR``, or ``PY_COLORS``
+2. ``FORCE_COLOR``
 3. ``--output-format=...``
 
 Setting ``NO_COLOR`` (to any value) will disable colorized output, while
-``FORCE_COLOR`` or ``PY_COLORS`` (to any value) will enable it, overriding
-the ``--output-format`` option if specified.
+``FORCE_COLOR`` (to any value) will enable it, overriding the
+``--output-format`` option if specified.
 
 
 Custom message formats
diff --git a/doc/whatsnew/fragments/3995.feature b/doc/whatsnew/fragments/3995.feature
index 5187567d09..37e66a9121 100644
--- a/doc/whatsnew/fragments/3995.feature
+++ b/doc/whatsnew/fragments/3995.feature
@@ -1,5 +1,6 @@
-Support for ``NO_COLOR`` and ``FORCE_COLOR`` (and ``PY_COLORS``, as an alias to ``FORCE_COLOR``) environment variables has been added.
-When running `pylint`, the reporter that reports to ``stdout`` will be modified according to the requested mode.
-The order is: ``NO_COLOR`` > ``FORCE_COLOR``, ``PY_COLORS`` > ``--output=...``.
+Support for ``NO_COLOR`` and ``FORCE_COLOR`` environment variables has been added.
+When running `pylint`, the reporter that reports to ``stdout`` will be modified according
+to the requested mode.
+The order is: ``NO_COLOR`` > ``FORCE_COLOR`` > ``--output=...``.
 
 Closes #3995 (https://github.com/pylint-dev/pylint/issues/3995).
diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index ba3c501fc4..da68a6fbee 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -74,7 +74,6 @@
 
 NO_COLOR = "NO_COLOR"
 FORCE_COLOR = "FORCE_COLOR"
-PY_COLORS = "PY_COLORS"
 
 WARN_FORCE_COLOR_SET = "FORCE_COLOR is set; ignoring `text` at stdout"
 WARN_NO_COLOR_SET = "NO_COLOR is set; ignoring `colorized` at stdout"
@@ -261,10 +260,9 @@ def _load_reporter_by_class(reporter_class: str) -> type[BaseReporter]:
 }
 
 
-def _handle_force_color_no_color(reporter: list[reporters.BaseReporter]) -> None:
+def _handle_force_color_no_color(reporters: list[reporters.BaseReporter]) -> list[reporters.BaseReporter]:
     """
-    Check ``NO_COLOR``, ``FORCE_COLOR``, ``PY_COLOR`` and modify the reporter list
-    accordingly.
+    Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list accordingly.
 
     Rules are presented in this table:
     +--------------+---------------+-----------------+------------------------------------------------------------+
@@ -281,9 +279,7 @@ def _handle_force_color_no_color(reporter: list[reporters.BaseReporter]) -> None
     +--------------+---------------+-----------------+------------------------------------------------------------+
     """
     no_color = _is_env_set_and_non_empty(NO_COLOR)
-    force_color = _is_env_set_and_non_empty(FORCE_COLOR) or _is_env_set_and_non_empty(
-        PY_COLORS
-    )
+    force_color = _is_env_set_and_non_empty(FORCE_COLOR)
 
     if no_color and force_color:
         warnings.warn(
@@ -293,34 +289,31 @@ def _handle_force_color_no_color(reporter: list[reporters.BaseReporter]) -> None
         )
         force_color = False
 
-    if no_color:
-        for idx, rep in enumerate(list(reporter)):
-            if not isinstance(rep, ColorizedTextReporter):
-                continue
-
-            if rep.out.buffer is sys.stdout.buffer:
-                warnings.warn(
-                    WARN_NO_COLOR_SET,
-                    ReporterWarning,
-                    stacklevel=2,
-                )
-                reporter.pop(idx)
-                reporter.append(TextReporter())
-
-    elif force_color:
-        for idx, rep in enumerate(list(reporter)):
-            # pylint: disable=unidiomatic-typecheck # Want explicit type check
-            if type(rep) is not TextReporter:
-                continue
+    final_reporters: list[reporters.BaseReporter] = []
+    
+    for idx, rep in enumerate(reporters):
+        if no_color and isinstance(rep, ColorizedTextReporter) and rep.out.buffer is sys.stdout.buffer:
+            warnings.warn(
+                WARN_NO_COLOR_SET,
+                ReporterWarning,
+                stacklevel=2,
+            )
+            final_reporters.append(TextReporter())
+
+   
+        # pylint: disable=unidiomatic-typecheck # Want explicit type check
+        elif force_color and type(rep) is TextReporter and rep.out.buffer is sys.stdout.buffer:
+            warnings.warn(
+                WARN_FORCE_COLOR_SET,
+                ReporterWarning,
+                stacklevel=2,
+            )
+            final_reporters.append(ColorizedTextReporter())
 
-            if rep.out.buffer is sys.stdout.buffer:
-                warnings.warn(
-                    WARN_FORCE_COLOR_SET,
-                    ReporterWarning,
-                    stacklevel=2,
-                )
-                reporter.pop(idx)
-                reporter.append(ColorizedTextReporter())
+        else:
+            final_reporters.append(rep)
+    
+    return final_reporters
 
 
 # pylint: disable=too-many-instance-attributes,too-many-public-methods
@@ -508,7 +501,7 @@ def _load_reporters(self, reporter_names: str) -> None:
             # Extend the lifetime of all opened output files
             close_output_files = stack.pop_all().close
 
-        _handle_force_color_no_color(sub_reporters)
+        sub_reporters = _handle_force_color_no_color(sub_reporters)
 
         if len(sub_reporters) > 1 or output_files:
             self.set_reporter(
diff --git a/tests/lint/test_pylinter.py b/tests/lint/test_pylinter.py
index 3f1267791b..b7f2ce42e3 100644
--- a/tests/lint/test_pylinter.py
+++ b/tests/lint/test_pylinter.py
@@ -20,7 +20,6 @@
     FORCE_COLOR,
     MANAGER,
     NO_COLOR,
-    PY_COLORS,
     WARN_BOTH_COLOR_SET,
     PyLinter,
     _handle_force_color_no_color,
@@ -139,11 +138,6 @@ def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
     [True, False],
     ids=lambda no_color: f"{no_color=}",
 )
-@pytest.mark.parametrize(
-    "py_colors",
-    [True, False],
-    ids=lambda py_colors: f"{py_colors=}",
-)
 @pytest.mark.parametrize(
     "force_color",
     [True, False],
@@ -153,16 +147,12 @@ def test_handle_force_color_no_color(
     monkeypatch: pytest.MonkeyPatch,
     recwarn: pytest.WarningsRecorder,
     no_color: bool,
-    py_colors: bool,
     force_color: bool,
     text_reporters: tuple[str],
     colorized_reporters: tuple[str],
 ) -> None:
     monkeypatch.setenv(NO_COLOR, "1" if no_color else "")
     monkeypatch.setenv(FORCE_COLOR, "1" if force_color else "")
-    monkeypatch.setenv(PY_COLORS, "1" if py_colors else "")
-
-    force_color = force_color or py_colors
 
     if STDOUT_TEXT in text_reporters or STDOUT_TEXT in colorized_reporters:
         monkeypatch.setattr(sys, STDOUT_TEXT, io.TextIOWrapper(io.BytesIO()))
diff --git a/tests/lint/test_utils.py b/tests/lint/test_utils.py
index 6d11adf797..04a883e94d 100644
--- a/tests/lint/test_utils.py
+++ b/tests/lint/test_utils.py
@@ -70,22 +70,17 @@ def test_issue_template_on_fatal_errors(capsys: pytest.CaptureFixture) -> None:
         ("", False),
         (0, True),
         (1, True),
-        (2, True),
         (False, True),
-        ("no", True),
-        ("off", True),
         ("on", True),
-        (True, True),
-        ("yes", True),
     ],
     ids=repr,
 )
 def test_is_env_set_and_non_empty(
-    monkeypatch: pytest.MonkeyPatch, value: Any, expected: bool
+    monkeypatch: pytest.MonkeyPatch, value: object, expected: bool
 ) -> None:
     """Test the function returns True if the environment variable is set and non-empty."""
     env_var = "TEST_VAR"
     if value is not None:
         monkeypatch.setenv(env_var, str(value))
 
-    assert _is_env_set_and_non_empty(env_var) == expected
+    assert _is_env_set_and_non_empty(env_var) is expected

From 6d558c74caa141f3ec9aee72749f19f76293faba Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 12 Jan 2025 15:18:18 +0000
Subject: [PATCH 08/16] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 pylint/lint/pylinter.py  | 24 +++++++++++++++++-------
 tests/lint/test_utils.py |  1 -
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index da68a6fbee..ae3d2476e7 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -260,9 +260,12 @@ def _load_reporter_by_class(reporter_class: str) -> type[BaseReporter]:
 }
 
 
-def _handle_force_color_no_color(reporters: list[reporters.BaseReporter]) -> list[reporters.BaseReporter]:
+def _handle_force_color_no_color(
+    reporters: list[reporters.BaseReporter],
+) -> list[reporters.BaseReporter]:
     """
-    Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list accordingly.
+    Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list
+    accordingly.
 
     Rules are presented in this table:
     +--------------+---------------+-----------------+------------------------------------------------------------+
@@ -290,9 +293,13 @@ def _handle_force_color_no_color(reporters: list[reporters.BaseReporter]) -> lis
         force_color = False
 
     final_reporters: list[reporters.BaseReporter] = []
-    
+
     for idx, rep in enumerate(reporters):
-        if no_color and isinstance(rep, ColorizedTextReporter) and rep.out.buffer is sys.stdout.buffer:
+        if (
+            no_color
+            and isinstance(rep, ColorizedTextReporter)
+            and rep.out.buffer is sys.stdout.buffer
+        ):
             warnings.warn(
                 WARN_NO_COLOR_SET,
                 ReporterWarning,
@@ -300,9 +307,12 @@ def _handle_force_color_no_color(reporters: list[reporters.BaseReporter]) -> lis
             )
             final_reporters.append(TextReporter())
 
-   
         # pylint: disable=unidiomatic-typecheck # Want explicit type check
-        elif force_color and type(rep) is TextReporter and rep.out.buffer is sys.stdout.buffer:
+        elif (
+            force_color
+            and type(rep) is TextReporter
+            and rep.out.buffer is sys.stdout.buffer
+        ):
             warnings.warn(
                 WARN_FORCE_COLOR_SET,
                 ReporterWarning,
@@ -312,7 +322,7 @@ def _handle_force_color_no_color(reporters: list[reporters.BaseReporter]) -> lis
 
         else:
             final_reporters.append(rep)
-    
+
     return final_reporters
 
 
diff --git a/tests/lint/test_utils.py b/tests/lint/test_utils.py
index 04a883e94d..5957208df9 100644
--- a/tests/lint/test_utils.py
+++ b/tests/lint/test_utils.py
@@ -4,7 +4,6 @@
 
 import unittest.mock
 from pathlib import Path, PosixPath
-from typing import Any
 
 import pytest
 

From 8d8f9884ddf7ff4c984b0e6eb6d1a1cc1ac77028 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Sun, 12 Jan 2025 16:21:12 +0100
Subject: [PATCH 09/16] Follow up to fixes

---
 pylint/lint/pylinter.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index ae3d2476e7..c93fcf9d07 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -261,11 +261,10 @@ def _load_reporter_by_class(reporter_class: str) -> type[BaseReporter]:
 
 
 def _handle_force_color_no_color(
-    reporters: list[reporters.BaseReporter],
+    reporters: Sequence[BaseReporter],
 ) -> list[reporters.BaseReporter]:
     """
-    Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list
-    accordingly.
+    Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list.
 
     Rules are presented in this table:
     +--------------+---------------+-----------------+------------------------------------------------------------+
@@ -294,7 +293,7 @@ def _handle_force_color_no_color(
 
     final_reporters: list[reporters.BaseReporter] = []
 
-    for idx, rep in enumerate(reporters):
+    for rep in reporters:
         if (
             no_color
             and isinstance(rep, ColorizedTextReporter)

From bb874735d36f898569b0939a941062a3bbb9154f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Sun, 12 Jan 2025 16:23:16 +0100
Subject: [PATCH 10/16] Another follow up

---
 pylint/lint/pylinter.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index c93fcf9d07..e5d6f754c1 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -291,7 +291,7 @@ def _handle_force_color_no_color(
         )
         force_color = False
 
-    final_reporters: list[reporters.BaseReporter] = []
+    final_reporters: list[BaseReporter] = []
 
     for rep in reporters:
         if (

From 68b07a4cee1f0501f8c3127024ecf4477c8078ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Sun, 12 Jan 2025 21:54:19 +0100
Subject: [PATCH 11/16] Make sure linting CI passes

---
 pylint/lint/pylinter.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index e5d6f754c1..fca5ee83e1 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -306,10 +306,10 @@ def _handle_force_color_no_color(
             )
             final_reporters.append(TextReporter())
 
-        # pylint: disable=unidiomatic-typecheck # Want explicit type check
         elif (
             force_color
-            and type(rep) is TextReporter
+            # Need type explicit check here
+            and type(rep) is TextReporter  # pylint: disable=unidiomatic-typecheck 
             and rep.out.buffer is sys.stdout.buffer
         ):
             warnings.warn(

From cf95d2723cf4eeb55f01b9f7ed0f8f1c9ef572b6 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 12 Jan 2025 20:55:09 +0000
Subject: [PATCH 12/16] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 pylint/lint/pylinter.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index fca5ee83e1..3c0d850b7c 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -309,7 +309,7 @@ def _handle_force_color_no_color(
         elif (
             force_color
             # Need type explicit check here
-            and type(rep) is TextReporter  # pylint: disable=unidiomatic-typecheck 
+            and type(rep) is TextReporter  # pylint: disable=unidiomatic-typecheck
             and rep.out.buffer is sys.stdout.buffer
         ):
             warnings.warn(

From c09eb185839df11633d50376cb77c80bd15ed074 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Sun, 12 Jan 2025 22:00:35 +0100
Subject: [PATCH 13/16] Rename to 'original_reporters'

---
 pylint/lint/pylinter.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index 3c0d850b7c..aac7515fd8 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -261,7 +261,7 @@ def _load_reporter_by_class(reporter_class: str) -> type[BaseReporter]:
 
 
 def _handle_force_color_no_color(
-    reporters: Sequence[BaseReporter],
+    original_reporters: Sequence[BaseReporter],
 ) -> list[reporters.BaseReporter]:
     """
     Check ``NO_COLOR`` and ``FORCE_COLOR``, and return the modified reporter list.
@@ -293,7 +293,7 @@ def _handle_force_color_no_color(
 
     final_reporters: list[BaseReporter] = []
 
-    for rep in reporters:
+    for rep in original_reporters:
         if (
             no_color
             and isinstance(rep, ColorizedTextReporter)

From cd55074064d72a3391df5fd4c3427a488535d3e1 Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Mon, 13 Jan 2025 21:55:36 +0100
Subject: [PATCH 14/16] Update doc/whatsnew/fragments/3995.feature
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Daniël van Noord <13665637+DanielNoord@users.noreply.github.com>
---
 doc/whatsnew/fragments/3995.feature | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/whatsnew/fragments/3995.feature b/doc/whatsnew/fragments/3995.feature
index 37e66a9121..93451dd720 100644
--- a/doc/whatsnew/fragments/3995.feature
+++ b/doc/whatsnew/fragments/3995.feature
@@ -3,4 +3,4 @@ When running `pylint`, the reporter that reports to ``stdout`` will be modified
 to the requested mode.
 The order is: ``NO_COLOR`` > ``FORCE_COLOR`` > ``--output=...``.
 
-Closes #3995 (https://github.com/pylint-dev/pylint/issues/3995).
+Closes #3995

From 260b671b756da1f4ec0f4f5432f2bd63189d14ef Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Tue, 11 Feb 2025 10:46:52 +0200
Subject: [PATCH 15/16] Constantify
 `test_handle_force_color_no_color_reporters`

Instead of runtime-generating it each time

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
---
 tests/lint/test_pylinter.py | 62 ++++++++++++-------------------------
 1 file changed, 19 insertions(+), 43 deletions(-)

diff --git a/tests/lint/test_pylinter.py b/tests/lint/test_pylinter.py
index b7f2ce42e3..af7739f9d9 100644
--- a/tests/lint/test_pylinter.py
+++ b/tests/lint/test_pylinter.py
@@ -7,9 +7,8 @@
 import io
 import os
 import sys
-import warnings
 from pathlib import Path
-from typing import Any, NoReturn
+from typing import Any, NamedTuple, NoReturn
 from unittest import mock
 from unittest.mock import patch
 
@@ -88,49 +87,21 @@ def test_open_pylinter_prefer_stubs(linter: PyLinter) -> None:
         MANAGER.prefer_stubs = False
 
 
-def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
-    if metafunc.function.__name__ != test_handle_force_color_no_color.__name__:
-        return
+class ReportersCombo(NamedTuple):
+    text_reporters: tuple[str, ...]
+    colorized_reporters: tuple[str, ...]
 
-    if (
-        TEXT_REPORTERS not in metafunc.fixturenames
-        or COLORIZED_REPORTERS not in metafunc.fixturenames
-    ):
-        warnings.warn(
-            f"Missing fixture {TEXT_REPORTERS} or {COLORIZED_REPORTERS} in"
-            f" {test_handle_force_color_no_color.function.__name__}??",
-            stacklevel=2,
-        )
-        return
-
-    parameters = []
-
-    reporter_combinations = [
-        ("file", STDOUT_TEXT),
-        ("file",),
-        (STDOUT_TEXT,),
-        ("",),
-    ]
-
-    for tr in list(reporter_combinations):
-        for cr in list(reporter_combinations):
-            tr = tuple(t for t in tr if t)
-            cr = tuple(t for t in cr if t)
-
-            total_reporters = len(tr) + len(cr)
-            unique_reporters = len(set(tr + cr))
 
-            if total_reporters == 0:
-                continue
-
-            if unique_reporters != total_reporters:
-                continue
-
-            parameters.append((tuple(tr), tuple(cr)))
-
-    metafunc.parametrize(
-        f"{TEXT_REPORTERS}, {COLORIZED_REPORTERS}", parameters, ids=repr
-    )
+test_handle_force_color_no_color_reporters = (
+    ReportersCombo(("file", "stdout"), ()),
+    ReportersCombo(("file",), ("stdout",)),
+    ReportersCombo(("file",), ()),
+    ReportersCombo(("stdout",), ("file",)),
+    ReportersCombo(("stdout",), ()),
+    ReportersCombo((), ("file", "stdout")),
+    ReportersCombo((), ("file",)),
+    ReportersCombo((), ("stdout",)),
+)
 
 
 @pytest.mark.parametrize(
@@ -143,6 +114,11 @@ def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
     [True, False],
     ids=lambda force_color: f"{force_color=}",
 )
+@pytest.mark.parametrize(
+    "text_reporters, colorized_reporters",
+    test_handle_force_color_no_color_reporters,
+    ids=repr,
+)
 def test_handle_force_color_no_color(
     monkeypatch: pytest.MonkeyPatch,
     recwarn: pytest.WarningsRecorder,

From eadd83a0f36061811bdcf508d362ae7a261ddc6a Mon Sep 17 00:00:00 2001
From: Stavros Ntentos <133706+stdedos@users.noreply.github.com>
Date: Sun, 23 Mar 2025 23:57:25 +0200
Subject: [PATCH 16/16] Update `doc/user_guide/usage/output.rst`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: 🇺🇦 Sviatoslav Sydorenko (Святослав Сидоренко) <wk.cvs.github@sydorenko.org.ua>
---
 doc/user_guide/usage/output.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/user_guide/usage/output.rst b/doc/user_guide/usage/output.rst
index 9de4085291..a9560876c2 100644
--- a/doc/user_guide/usage/output.rst
+++ b/doc/user_guide/usage/output.rst
@@ -30,8 +30,8 @@ variables. The precedence for determining output format is as follows:
 2. ``FORCE_COLOR``
 3. ``--output-format=...``
 
-Setting ``NO_COLOR`` (to any value) will disable colorized output, while
-``FORCE_COLOR`` (to any value) will enable it, overriding the
+Setting ``NO_COLOR`` (to any non-empty value) will disable colorized output,
+while ``FORCE_COLOR`` (to any non-empty value) will enable it, overriding the
 ``--output-format`` option if specified.