From 6ea5d5b70db40eeb293012cccf89f69b214e7388 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 Aug 2025 15:09:50 +0000
Subject: [PATCH 01/10] Initial plan


From e1a4d4834553a418d87cd935fd284f33e663f3b2 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 Aug 2025 15:20:28 +0000
Subject: [PATCH 02/10] Start creating copilot instructions file

Co-authored-by: Pierre-Sassoulas <5493666+Pierre-Sassoulas@users.noreply.github.com>
---
 doc/user_guide/checkers/features.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/user_guide/checkers/features.rst b/doc/user_guide/checkers/features.rst
index d4fb243c8d..510d95ec62 100644
--- a/doc/user_guide/checkers/features.rst
+++ b/doc/user_guide/checkers/features.rst
@@ -106,8 +106,8 @@ Basic checker Messages
   a try...finally block: the exceptions raised in the try clause will be
   silently swallowed instead of being re-raised.
 :break-in-finally (W0137): *'break' discouraged inside 'finally' clause*
-  Emitted when the `break` keyword is found inside a finally clause. This
-  will raise a SyntaxWarning starting in Python 3.14.
+  Emitted when the `break` keyword is found inside a finally clause. This will
+  raise a SyntaxWarning starting in Python 3.14.
 :continue-in-finally (W0136): *'continue' discouraged inside 'finally' clause*
   Emitted when the `continue` keyword is found inside a finally clause. This
   will raise a SyntaxWarning starting in Python 3.14.
@@ -193,7 +193,7 @@ Basic checker Messages
 :missing-parentheses-for-call-in-test (W0126): *Using a conditional statement with potentially wrong function or method call due to missing parentheses*
   Emitted when a conditional statement (If or ternary if) seems to wrongly call
   a function due to missing parentheses
-:comparison-of-constants (R0133): *Comparison between constants: '%s %s %s' has a constant value*
+:comparison-of-constants (R0133): *Comparison between constants: "%s %s %s" has a constant value*
   When two literals are compared with each other the result is a constant.
   Using the constant directly is both easier to read and more performant.
   Initializing 'True' and 'False' this way is not required since Python 2.3.

From 7d3a9aa8e7565bbc07aae57fc792fd121f314f66 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 Aug 2025 15:23:50 +0000
Subject: [PATCH 03/10] Create comprehensive copilot instructions with
 validated commands

Co-authored-by: Pierre-Sassoulas <5493666+Pierre-Sassoulas@users.noreply.github.com>
---
 .github/copilot-instructions.md | 112 ++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 .github/copilot-instructions.md

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 0000000000..cf9191c081
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,112 @@
+# Pylint Development Instructions
+
+Always follow these instructions first and fallback to additional search and context gathering only if the information in these instructions is incomplete or found to be in error.
+
+## Working Effectively
+
+- Bootstrap and set up the development environment:
+  - `python --version` -- verify Python 3.10+ is available
+  - `pip install -e .` -- install pylint in development mode (takes ~30-60 seconds)
+  - `pip install coverage pytest pytest-cov pytest-xdist tox` -- install core test dependencies
+
+- Run basic validation:
+  - `pylint --help` -- verify pylint is working correctly
+  - `pylint --disable=all --enable=E,F pylint/` -- run pylint on itself for errors only (takes ~20 seconds, some import errors expected)
+
+- Run tests:
+  - `pytest tests/test_check_parallel.py -v` -- run a quick test file (~2 seconds)
+  - `pytest tests/test_self.py -v` -- run core functionality tests (~15 seconds)
+  - `pytest tests/test_functional.py::test_functional --maxfail=5 -q` -- run functional tests (takes ~60 seconds, NEVER CANCEL, set timeout to 120+ seconds)
+  - **NEVER CANCEL:** Full test suite takes 60+ seconds. Always wait for completion.
+
+- Install additional development dependencies:
+  - `pip install pre-commit` -- for code formatting and linting
+  - `cd doc && pip install -r requirements.txt` -- for documentation (requires network access)
+
+- Build documentation:
+  - `cd doc && make install-dependencies` -- install doc dependencies (~10 seconds)
+  - `cd doc && make html` -- build documentation (~3 minutes, NEVER CANCEL, may fail without network access)
+  - **NEVER CANCEL:** Documentation build takes up to 3 minutes. Set timeout to 300+ seconds.
+
+## Validation
+
+- Always run pylint on your changes before committing:
+  - `pylint --rcfile=pylintrc --fail-on=I path/to/your/changes.py` -- standard pylint run
+  - `pylint --disable=all --enable=E,F,W path/to/your/changes.py` -- focus on errors and warnings
+
+- Run formatting and pre-commit checks:
+  - `pre-commit run --all-files` -- run all formatting checks (requires network for initial setup)
+  - **Network dependency:** pre-commit may fail in isolated environments due to hook downloads
+
+- **VALIDATION SCENARIOS:** Always test your changes by:
+  - Running pylint on a sample Python file: `echo "def badFunction(): pass" > /tmp/test_sample.py && pylint --enable=C0103 /tmp/test_sample.py` (should find naming issues)
+  - Verifying pylint CLI still works: `pylint --help` and `pylint --list-msgs | head -10`
+  - Testing message ID functionality: `pylint --help-msg=C0103` (should show invalid-name help)
+  - Checking specific module: `pylint --rcfile=pylintrc --fail-on=I pylint/__init__.py` (should get 10.00/10 rating)
+
+## Common Tasks
+
+### Running specific test categories:
+- Functional tests: `pytest tests/test_functional.py -k "test_name" -v`
+- Individual functional test: `pytest "tests/test_functional.py::test_functional[abstract_class_instantiated]" -v` (~1 second)
+- Unit tests: `pytest tests/test_self.py -v`
+- Quick smoke test: `pytest tests/test_func.py tests/test_check_parallel.py -v` (~2 seconds, 53 tests)
+
+### Understanding the codebase structure:
+```
+pylint/                    # Main package
+├── checkers/             # All pylint checkers (rules)
+├── config/               # Configuration handling
+├── message/              # Message system
+├── reporters/            # Output formatters
+├── testutils/            # Testing utilities
+└── extensions/           # Optional extensions
+
+tests/                     # Test suite
+├── functional/           # Functional test files (.py files with expected output)
+├── test_*.py            # Unit tests
+└── data/                # Test data files
+
+doc/                      # Documentation
+├── user_guide/          # User documentation
+├── development_guide/   # Developer documentation
+└── additional_tools/    # Tools documentation
+```
+
+### Key files to know:
+- `pyproject.toml` -- Main configuration (dependencies, build, tools)
+- `tox.ini` -- Multi-environment testing configuration
+- `.pre-commit-config.yaml` -- Code quality checks configuration
+- `pylintrc` -- Pylint's own configuration
+- `script/` -- Utility scripts for development
+
+### Creating new checkers:
+- Use `python script/get_unused_message_id_category.py` to get unused message IDs (outputs next available ID)
+- Look at existing checkers in `pylint/checkers/` for patterns
+- Add functional tests in `tests/functional/`
+
+### Working with functional tests:
+- Tests are in `tests/functional/` with `.py` files and corresponding `.txt` files for expected output
+- Run individual functional test: `pytest tests/test_functional.py::test_functional[test_name] -v`
+
+## Critical Timing Information
+
+- **NEVER CANCEL:** All operations that show "NEVER CANCEL" may take significant time
+- Functional test suite: 60 seconds (set timeout to 120+ seconds)
+- Documentation build: 180 seconds (set timeout to 300+ seconds)
+- Full pylint self-check: 20 seconds (set timeout to 60+ seconds)
+- Individual test files: 1-15 seconds
+
+## Known Issues and Workarounds
+
+- **Network connectivity required:** Documentation build and pre-commit setup require internet access
+- **Tox may fail:** In isolated environments, use direct pytest and pip commands instead of tox
+- **Import errors in self-check:** Some import errors when running pylint on itself are expected (git dependencies not installed)
+
+## Environment Limitations
+
+- Some network-dependent operations may fail in isolated environments
+- Use direct pip and pytest commands when tox environments fail to build
+- Documentation build requires network access to fetch external inventories
+
+Always build and exercise your changes by running pylint on sample code to ensure functionality works correctly.
\ No newline at end of file

From 8cc79d53e0b2b01d86aa0853696688ade6498936 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 Aug 2025 15:35:24 +0000
Subject: [PATCH 04/10] Regenerate copilot instructions from contributor guide
 and revert unrelated changes

Co-authored-by: Pierre-Sassoulas <5493666+Pierre-Sassoulas@users.noreply.github.com>
---
 .github/copilot-instructions.md      | 241 ++++++++++++++++++---------
 doc/user_guide/checkers/features.rst |   6 +-
 2 files changed, 163 insertions(+), 84 deletions(-)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index cf9191c081..51977131f9 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -2,111 +2,190 @@
 
 Always follow these instructions first and fallback to additional search and context gathering only if the information in these instructions is incomplete or found to be in error.
 
-## Working Effectively
-
-- Bootstrap and set up the development environment:
-  - `python --version` -- verify Python 3.10+ is available
-  - `pip install -e .` -- install pylint in development mode (takes ~30-60 seconds)
-  - `pip install coverage pytest pytest-cov pytest-xdist tox` -- install core test dependencies
-
-- Run basic validation:
-  - `pylint --help` -- verify pylint is working correctly
-  - `pylint --disable=all --enable=E,F pylint/` -- run pylint on itself for errors only (takes ~20 seconds, some import errors expected)
-
-- Run tests:
-  - `pytest tests/test_check_parallel.py -v` -- run a quick test file (~2 seconds)
-  - `pytest tests/test_self.py -v` -- run core functionality tests (~15 seconds)
-  - `pytest tests/test_functional.py::test_functional --maxfail=5 -q` -- run functional tests (takes ~60 seconds, NEVER CANCEL, set timeout to 120+ seconds)
-  - **NEVER CANCEL:** Full test suite takes 60+ seconds. Always wait for completion.
-
-- Install additional development dependencies:
-  - `pip install pre-commit` -- for code formatting and linting
-  - `cd doc && pip install -r requirements.txt` -- for documentation (requires network access)
-
-- Build documentation:
-  - `cd doc && make install-dependencies` -- install doc dependencies (~10 seconds)
-  - `cd doc && make html` -- build documentation (~3 minutes, NEVER CANCEL, may fail without network access)
-  - **NEVER CANCEL:** Documentation build takes up to 3 minutes. Set timeout to 300+ seconds.
-
-## Validation
-
-- Always run pylint on your changes before committing:
-  - `pylint --rcfile=pylintrc --fail-on=I path/to/your/changes.py` -- standard pylint run
-  - `pylint --disable=all --enable=E,F,W path/to/your/changes.py` -- focus on errors and warnings
-
-- Run formatting and pre-commit checks:
-  - `pre-commit run --all-files` -- run all formatting checks (requires network for initial setup)
-  - **Network dependency:** pre-commit may fail in isolated environments due to hook downloads
-
-- **VALIDATION SCENARIOS:** Always test your changes by:
-  - Running pylint on a sample Python file: `echo "def badFunction(): pass" > /tmp/test_sample.py && pylint --enable=C0103 /tmp/test_sample.py` (should find naming issues)
-  - Verifying pylint CLI still works: `pylint --help` and `pylint --list-msgs | head -10`
-  - Testing message ID functionality: `pylint --help-msg=C0103` (should show invalid-name help)
-  - Checking specific module: `pylint --rcfile=pylintrc --fail-on=I pylint/__init__.py` (should get 10.00/10 rating)
-
-## Common Tasks
+## Development Environment Setup
+
+### Basic Installation
+Clone and set up pylint development environment:
+- `git clone https://github.com/pylint-dev/pylint` -- clone repository
+- `cd pylint` -- enter directory
+- `python3 --version` -- verify Python 3.8+ is available (development requires 3.8+)
+- `python3 -m venv venv` -- create virtual environment
+- `source venv/bin/activate` -- activate virtual environment (Linux/Mac)
+- `pip install -r requirements_test_min.txt` -- install test dependencies (~30 seconds)
+- `pip install -e .` -- install pylint in editable mode (~30-60 seconds)
+
+### Optional Setup Steps
+- `pre-commit install` -- enable pre-commit hooks for autoformatting
+- `pip install pre-commit` -- install pre-commit separately if needed
+
+### Astroid Development (if needed)
+If working on astroid changes:
+- `git clone https://github.com/pylint-dev/astroid.git` -- clone astroid
+- `pip install -e astroid/` -- install astroid in editable mode
+- `cd astroid/ && git switch my-astroid-dev-branch` -- switch to development branch
+
+## Running Tests
+
+### Core Test Commands
+- `pytest tests/test_functional.py -k test_functional` -- run functional tests (~60 seconds, NEVER CANCEL, set timeout to 120+ seconds)
+- `pytest tests/` -- run all tests (several minutes, NEVER CANCEL, set timeout to 300+ seconds)
+- `python3 -m pytest` -- run tests with local python
+- `pytest tests/test_check_parallel.py -v` -- quick test file (~2 seconds)
+
+### Specific Test Types
+- **Functional tests:** `pytest "tests/test_functional.py::test_functional[missing_kwoa_py3]"` -- single functional test (~1 second)
+- **Unit tests:** Located in `/tests/` directory, test specific pylint functionality
+- **Configuration tests:** In `/tests/config/functional/` for testing configuration loading
+- **Primer tests:** `pytest -m primer_stdlib --primer-stdlib` -- test on stdlib for crashes
+
+### Test with Coverage
+- `pytest tests/message/ --cov=pylint.message` -- run with coverage
+- `coverage html` -- generate HTML coverage report
+
+### Tox Usage (Optional)
+- `python -m tox` -- run all tox environments
+- `python -m tox -epy313` -- run Python 3.13 suite only
+- `python -m tox -epylint` -- run pylint on pylint's codebase
+- `python -m tox -eformatting` -- run formatting checks
+- `python -m tox --recreate` -- recreate environments (recommended)
+- `python -m tox -e py310 -- -k test_functional` -- run specific tests in tox
+
+## Documentation
+
+### Building Documentation
+- `make -C doc/ install-dependencies` -- install doc dependencies (~10 seconds)
+- `make -C doc/ html` -- build documentation (~3 minutes, NEVER CANCEL, set timeout to 300+ seconds)
+- `make -C doc/ clean` -- clean build files when starting from scratch
+- `tox -e docs` -- alternative way to build docs
+
+**Network dependency:** Documentation build requires internet access to fetch external inventories.
+
+## Validation and Quality Checks
+
+### Running Pylint on Code
+- `pylint --help` -- verify pylint installation works
+- `pylint --disable=all --enable=E,F pylint/` -- run pylint on itself for errors only (~20 seconds)
+- `pylint --rcfile=pylintrc --fail-on=I path/to/your/changes.py` -- standard pylint run
+- `pylint --disable=all --enable=E,F,W path/to/your/changes.py` -- focus on errors and warnings
+
+### Pre-commit and Formatting
+- `pre-commit run --all-files` -- run all formatting checks (requires network for initial setup)
+- **Network dependency:** pre-commit may fail in isolated environments due to hook downloads
+
+### Validation Test Scenarios
+Always test your changes with these validation scenarios:
+- `echo "def badFunction(): pass" > /tmp/test_sample.py && pylint --enable=C0103 /tmp/test_sample.py` -- should find naming issues
+- `pylint --help` and `pylint --list-msgs | head -10` -- verify CLI functionality
+- `pylint --help-msg=C0103` -- should show invalid-name help
+- `pylint --rcfile=pylintrc --fail-on=I pylint/__init__.py` -- should get 10.00/10 rating
+
+## Writing Tests
+
+### Functional Tests
+Located in `/tests/functional/`, consists of `.py` test files with corresponding `.txt` expected output files:
+- Annotate lines where messages are expected: `a, b, c = 1 # [unbalanced-tuple-unpacking]`
+- Multiple messages on same line: `a, b, c = 1.test # [unbalanced-tuple-unpacking, no-member]`
+- Use offset syntax for special cases: `# +1: [singleton-comparison]`
+- **Run and update:** `python tests/test_functional.py --update-functional-output -k "test_functional[test_name]"`
+
+### Test File Organization
+- **New checkers:** Create `new_checker_message.py` in `/tests/functional/n/`
+- **Extensions:** Place in `/tests/functional/ext/extension_name/`
+- **Regression tests:** Place in `/tests/r/regression/` with `regression_` prefix
+- **Configuration tests:** Place in `/tests/config/functional/`
+
+### Configuration Test Files
+Create `.result.json` files with configuration differences from standard config:
+```json
+{
+    "functional_append": {
+        "disable": [["a-message-to-be-added"]]
+    },
+    "jobs": 10
+}
+```
 
-### Running specific test categories:
-- Functional tests: `pytest tests/test_functional.py -k "test_name" -v`
-- Individual functional test: `pytest "tests/test_functional.py::test_functional[abstract_class_instantiated]" -v` (~1 second)
-- Unit tests: `pytest tests/test_self.py -v`
-- Quick smoke test: `pytest tests/test_func.py tests/test_check_parallel.py -v` (~2 seconds, 53 tests)
+## Codebase Structure
 
-### Understanding the codebase structure:
 ```
 pylint/                    # Main package
-├── checkers/             # All pylint checkers (rules)
-├── config/               # Configuration handling
-├── message/              # Message system
-├── reporters/            # Output formatters
-├── testutils/            # Testing utilities
-└── extensions/           # Optional extensions
+├── checkers/             # All pylint checkers (rules implementation)
+├── config/               # Configuration handling and parsing
+├── message/              # Message system and formatting
+├── reporters/            # Output formatters (text, json, etc.)
+├── testutils/            # Testing utilities and helpers
+└── extensions/           # Optional extensions and plugins
 
 tests/                     # Test suite
-├── functional/           # Functional test files (.py files with expected output)
+├── functional/           # Functional test files (.py + .txt expected output)
+├── config/functional/    # Configuration functional tests
+├── r/regression/         # Regression tests
 ├── test_*.py            # Unit tests
-└── data/                # Test data files
+└── regrtest_data/       # Test data files
 
 doc/                      # Documentation
 ├── user_guide/          # User documentation
-├── development_guide/   # Developer documentation
+├── development_guide/   # Developer and contributor documentation
+│   ├── contributor_guide/    # Setup, testing, contribution guidelines
+│   ├── technical_reference/  # Technical implementation details
+│   └── how_tos/             # Guides for custom checkers, plugins
 └── additional_tools/    # Tools documentation
+
+script/                   # Development utility scripts
 ```
 
-### Key files to know:
+### Key Files
 - `pyproject.toml` -- Main configuration (dependencies, build, tools)
 - `tox.ini` -- Multi-environment testing configuration
-- `.pre-commit-config.yaml` -- Code quality checks configuration
+- `.pre-commit-config.yaml` -- Code quality checks configuration  
 - `pylintrc` -- Pylint's own configuration
-- `script/` -- Utility scripts for development
+- `requirements_test_min.txt` -- Minimal test dependencies
+
+## Creating New Checkers
+
+### Getting Started
+- `python script/get_unused_message_id_category.py` -- get next available message ID
+- Study existing checkers in `pylint/checkers/` for patterns
+- Read technical reference documentation in `doc/development_guide/technical_reference/`
+- Use `astroid.extract_node` for AST manipulation
+
+### Workflow
+1. Create checker class in appropriate `pylint/checkers/` file
+2. Add functional tests in `tests/functional/`
+3. Search existing code for warning message to find where logic exists
+4. Test with sample code to ensure functionality works
 
-### Creating new checkers:
-- Use `python script/get_unused_message_id_category.py` to get unused message IDs (outputs next available ID)
-- Look at existing checkers in `pylint/checkers/` for patterns
-- Add functional tests in `tests/functional/`
+## Pull Request Guidelines
 
-### Working with functional tests:
-- Tests are in `tests/functional/` with `.py` files and corresponding `.txt` files for expected output
-- Run individual functional test: `pytest tests/test_functional.py::test_functional[test_name] -v`
+### Before Submitting
+- Use Python 3.8+ for development (required for latest AST parser and pre-commit hooks)
+- Write comprehensive commit messages relating to tracker issues
+- Keep changes small and separate consensual from opinionated changes
+- Add news fragment: `towncrier create <IssueNumber>.<type>`
+
+### Documentation Changes
+- Document non-trivial changes
+- Generate docs with `tox -e docs`
+- Maintainers may label issues `skip-news` if no changelog needed
+
+### Contribution Credits
+- Add emails/names to `script/.contributors_aliases.json` if using multiple identities
 
 ## Critical Timing Information
 
 - **NEVER CANCEL:** All operations that show "NEVER CANCEL" may take significant time
-- Functional test suite: 60 seconds (set timeout to 120+ seconds)
-- Documentation build: 180 seconds (set timeout to 300+ seconds)
-- Full pylint self-check: 20 seconds (set timeout to 60+ seconds)
-- Individual test files: 1-15 seconds
+- **Full test suite:** 60+ seconds (set timeout to 120+ seconds)
+- **Documentation build:** 180 seconds (set timeout to 300+ seconds)
+- **Functional tests:** 60 seconds (set timeout to 120+ seconds)
+- **Pylint self-check:** 20 seconds (set timeout to 60+ seconds)
+- **Individual test files:** 1-15 seconds
+- **Installation steps:** 30-60 seconds each
 
-## Known Issues and Workarounds
+## Environment Limitations and Workarounds
 
 - **Network connectivity required:** Documentation build and pre-commit setup require internet access
-- **Tox may fail:** In isolated environments, use direct pytest and pip commands instead of tox
+- **Tox failures:** In isolated environments, use direct pytest and pip commands instead of tox
 - **Import errors in self-check:** Some import errors when running pylint on itself are expected (git dependencies not installed)
+- **Build environments:** Use direct pip/pytest commands when tox environments fail to build
 
-## Environment Limitations
-
-- Some network-dependent operations may fail in isolated environments
-- Use direct pip and pytest commands when tox environments fail to build
-- Documentation build requires network access to fetch external inventories
-
-Always build and exercise your changes by running pylint on sample code to ensure functionality works correctly.
\ No newline at end of file
+Always validate your changes by running pylint on sample code to ensure functionality works correctly.
\ No newline at end of file
diff --git a/doc/user_guide/checkers/features.rst b/doc/user_guide/checkers/features.rst
index 510d95ec62..d4fb243c8d 100644
--- a/doc/user_guide/checkers/features.rst
+++ b/doc/user_guide/checkers/features.rst
@@ -106,8 +106,8 @@ Basic checker Messages
   a try...finally block: the exceptions raised in the try clause will be
   silently swallowed instead of being re-raised.
 :break-in-finally (W0137): *'break' discouraged inside 'finally' clause*
-  Emitted when the `break` keyword is found inside a finally clause. This will
-  raise a SyntaxWarning starting in Python 3.14.
+  Emitted when the `break` keyword is found inside a finally clause. This
+  will raise a SyntaxWarning starting in Python 3.14.
 :continue-in-finally (W0136): *'continue' discouraged inside 'finally' clause*
   Emitted when the `continue` keyword is found inside a finally clause. This
   will raise a SyntaxWarning starting in Python 3.14.
@@ -193,7 +193,7 @@ Basic checker Messages
 :missing-parentheses-for-call-in-test (W0126): *Using a conditional statement with potentially wrong function or method call due to missing parentheses*
   Emitted when a conditional statement (If or ternary if) seems to wrongly call
   a function due to missing parentheses
-:comparison-of-constants (R0133): *Comparison between constants: "%s %s %s" has a constant value*
+:comparison-of-constants (R0133): *Comparison between constants: '%s %s %s' has a constant value*
   When two literals are compared with each other the result is a constant.
   Using the constant directly is both easier to read and more performant.
   Initializing 'True' and 'False' this way is not required since Python 2.3.

From 0431da80f18a46f4309ce06c4316e83ebcdb8b0b Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Fri, 29 Aug 2025 10:10:10 +0200
Subject: [PATCH 05/10] Apply pre-commit

---
 .github/copilot-instructions.md | 108 +++++++++++++++++++++++---------
 1 file changed, 79 insertions(+), 29 deletions(-)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 51977131f9..252bc242ff 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -1,11 +1,15 @@
 # Pylint Development Instructions
 
-Always follow these instructions first and fallback to additional search and context gathering only if the information in these instructions is incomplete or found to be in error.
+Always follow these instructions first and fallback to additional search and context
+gathering only if the information in these instructions is incomplete or found to be in
+error.
 
 ## Development Environment Setup
 
 ### Basic Installation
+
 Clone and set up pylint development environment:
+
 - `git clone https://github.com/pylint-dev/pylint` -- clone repository
 - `cd pylint` -- enter directory
 - `python3 --version` -- verify Python 3.8+ is available (development requires 3.8+)
@@ -15,11 +19,14 @@ Clone and set up pylint development environment:
 - `pip install -e .` -- install pylint in editable mode (~30-60 seconds)
 
 ### Optional Setup Steps
+
 - `pre-commit install` -- enable pre-commit hooks for autoformatting
 - `pip install pre-commit` -- install pre-commit separately if needed
 
 ### Astroid Development (if needed)
+
 If working on astroid changes:
+
 - `git clone https://github.com/pylint-dev/astroid.git` -- clone astroid
 - `pip install -e astroid/` -- install astroid in editable mode
 - `cd astroid/ && git switch my-astroid-dev-branch` -- switch to development branch
@@ -27,22 +34,32 @@ If working on astroid changes:
 ## Running Tests
 
 ### Core Test Commands
-- `pytest tests/test_functional.py -k test_functional` -- run functional tests (~60 seconds, NEVER CANCEL, set timeout to 120+ seconds)
-- `pytest tests/` -- run all tests (several minutes, NEVER CANCEL, set timeout to 300+ seconds)
+
+- `pytest tests/test_functional.py -k test_functional` -- run functional tests (~60
+  seconds, NEVER CANCEL, set timeout to 120+ seconds)
+- `pytest tests/` -- run all tests (several minutes, NEVER CANCEL, set timeout to 300+
+  seconds)
 - `python3 -m pytest` -- run tests with local python
 - `pytest tests/test_check_parallel.py -v` -- quick test file (~2 seconds)
 
 ### Specific Test Types
-- **Functional tests:** `pytest "tests/test_functional.py::test_functional[missing_kwoa_py3]"` -- single functional test (~1 second)
+
+- **Functional tests:**
+  `pytest "tests/test_functional.py::test_functional[missing_kwoa_py3]"` -- single
+  functional test (~1 second)
 - **Unit tests:** Located in `/tests/` directory, test specific pylint functionality
-- **Configuration tests:** In `/tests/config/functional/` for testing configuration loading
-- **Primer tests:** `pytest -m primer_stdlib --primer-stdlib` -- test on stdlib for crashes
+- **Configuration tests:** In `/tests/config/functional/` for testing configuration
+  loading
+- **Primer tests:** `pytest -m primer_stdlib --primer-stdlib` -- test on stdlib for
+  crashes
 
 ### Test with Coverage
+
 - `pytest tests/message/ --cov=pylint.message` -- run with coverage
 - `coverage html` -- generate HTML coverage report
 
 ### Tox Usage (Optional)
+
 - `python -m tox` -- run all tox environments
 - `python -m tox -epy313` -- run Python 3.13 suite only
 - `python -m tox -epylint` -- run pylint on pylint's codebase
@@ -53,55 +70,77 @@ If working on astroid changes:
 ## Documentation
 
 ### Building Documentation
+
 - `make -C doc/ install-dependencies` -- install doc dependencies (~10 seconds)
-- `make -C doc/ html` -- build documentation (~3 minutes, NEVER CANCEL, set timeout to 300+ seconds)
+- `make -C doc/ html` -- build documentation (~3 minutes, NEVER CANCEL, set timeout to
+  300+ seconds)
 - `make -C doc/ clean` -- clean build files when starting from scratch
 - `tox -e docs` -- alternative way to build docs
 
-**Network dependency:** Documentation build requires internet access to fetch external inventories.
+**Network dependency:** Documentation build requires internet access to fetch external
+inventories.
 
 ## Validation and Quality Checks
 
 ### Running Pylint on Code
+
 - `pylint --help` -- verify pylint installation works
-- `pylint --disable=all --enable=E,F pylint/` -- run pylint on itself for errors only (~20 seconds)
+- `pylint --disable=all --enable=E,F pylint/` -- run pylint on itself for errors only
+  (~20 seconds)
 - `pylint --rcfile=pylintrc --fail-on=I path/to/your/changes.py` -- standard pylint run
-- `pylint --disable=all --enable=E,F,W path/to/your/changes.py` -- focus on errors and warnings
+- `pylint --disable=all --enable=E,F,W path/to/your/changes.py` -- focus on errors and
+  warnings
 
 ### Pre-commit and Formatting
-- `pre-commit run --all-files` -- run all formatting checks (requires network for initial setup)
-- **Network dependency:** pre-commit may fail in isolated environments due to hook downloads
+
+- `pre-commit run --all-files` -- run all formatting checks (requires network for
+  initial setup)
+- **Network dependency:** pre-commit may fail in isolated environments due to hook
+  downloads
 
 ### Validation Test Scenarios
+
 Always test your changes with these validation scenarios:
-- `echo "def badFunction(): pass" > /tmp/test_sample.py && pylint --enable=C0103 /tmp/test_sample.py` -- should find naming issues
+
+- `echo "def badFunction(): pass" > /tmp/test_sample.py && pylint --enable=C0103 /tmp/test_sample.py`
+  -- should find naming issues
 - `pylint --help` and `pylint --list-msgs | head -10` -- verify CLI functionality
 - `pylint --help-msg=C0103` -- should show invalid-name help
-- `pylint --rcfile=pylintrc --fail-on=I pylint/__init__.py` -- should get 10.00/10 rating
+- `pylint --rcfile=pylintrc --fail-on=I pylint/__init__.py` -- should get 10.00/10
+  rating
 
 ## Writing Tests
 
 ### Functional Tests
-Located in `/tests/functional/`, consists of `.py` test files with corresponding `.txt` expected output files:
-- Annotate lines where messages are expected: `a, b, c = 1 # [unbalanced-tuple-unpacking]`
-- Multiple messages on same line: `a, b, c = 1.test # [unbalanced-tuple-unpacking, no-member]`
+
+Located in `/tests/functional/`, consists of `.py` test files with corresponding `.txt`
+expected output files:
+
+- Annotate lines where messages are expected:
+  `a, b, c = 1 # [unbalanced-tuple-unpacking]`
+- Multiple messages on same line:
+  `a, b, c = 1.test # [unbalanced-tuple-unpacking, no-member]`
 - Use offset syntax for special cases: `# +1: [singleton-comparison]`
-- **Run and update:** `python tests/test_functional.py --update-functional-output -k "test_functional[test_name]"`
+- **Run and update:**
+  `python tests/test_functional.py --update-functional-output -k "test_functional[test_name]"`
 
 ### Test File Organization
+
 - **New checkers:** Create `new_checker_message.py` in `/tests/functional/n/`
 - **Extensions:** Place in `/tests/functional/ext/extension_name/`
 - **Regression tests:** Place in `/tests/r/regression/` with `regression_` prefix
 - **Configuration tests:** Place in `/tests/config/functional/`
 
 ### Configuration Test Files
+
 Create `.result.json` files with configuration differences from standard config:
+
 ```json
 {
-    "functional_append": {
-        "disable": [["a-message-to-be-added"]]
-    },
-    "jobs": 10
+  "functional_append": {
+    "disable": [["a-message-to-be-added"]]
+  },
+  "jobs": 10
 }
 ```
 
@@ -135,21 +174,24 @@ script/                   # Development utility scripts
 ```
 
 ### Key Files
+
 - `pyproject.toml` -- Main configuration (dependencies, build, tools)
 - `tox.ini` -- Multi-environment testing configuration
-- `.pre-commit-config.yaml` -- Code quality checks configuration  
+- `.pre-commit-config.yaml` -- Code quality checks configuration
 - `pylintrc` -- Pylint's own configuration
 - `requirements_test_min.txt` -- Minimal test dependencies
 
 ## Creating New Checkers
 
 ### Getting Started
+
 - `python script/get_unused_message_id_category.py` -- get next available message ID
 - Study existing checkers in `pylint/checkers/` for patterns
 - Read technical reference documentation in `doc/development_guide/technical_reference/`
 - Use `astroid.extract_node` for AST manipulation
 
 ### Workflow
+
 1. Create checker class in appropriate `pylint/checkers/` file
 2. Add functional tests in `tests/functional/`
 3. Search existing code for warning message to find where logic exists
@@ -158,17 +200,20 @@ script/                   # Development utility scripts
 ## Pull Request Guidelines
 
 ### Before Submitting
+
 - Use Python 3.8+ for development (required for latest AST parser and pre-commit hooks)
 - Write comprehensive commit messages relating to tracker issues
 - Keep changes small and separate consensual from opinionated changes
 - Add news fragment: `towncrier create <IssueNumber>.<type>`
 
 ### Documentation Changes
+
 - Document non-trivial changes
 - Generate docs with `tox -e docs`
 - Maintainers may label issues `skip-news` if no changelog needed
 
 ### Contribution Credits
+
 - Add emails/names to `script/.contributors_aliases.json` if using multiple identities
 
 ## Critical Timing Information
@@ -183,9 +228,14 @@ script/                   # Development utility scripts
 
 ## Environment Limitations and Workarounds
 
-- **Network connectivity required:** Documentation build and pre-commit setup require internet access
-- **Tox failures:** In isolated environments, use direct pytest and pip commands instead of tox
-- **Import errors in self-check:** Some import errors when running pylint on itself are expected (git dependencies not installed)
-- **Build environments:** Use direct pip/pytest commands when tox environments fail to build
-
-Always validate your changes by running pylint on sample code to ensure functionality works correctly.
\ No newline at end of file
+- **Network connectivity required:** Documentation build and pre-commit setup require
+  internet access
+- **Tox failures:** In isolated environments, use direct pytest and pip commands instead
+  of tox
+- **Import errors in self-check:** Some import errors when running pylint on itself are
+  expected (git dependencies not installed)
+- **Build environments:** Use direct pip/pytest commands when tox environments fail to
+  build
+
+Always validate your changes by running pylint on sample code to ensure functionality
+works correctly.

From 7836c6b61533ffe4c857dd4ffddecf606ddee6c7 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 29 Aug 2025 08:52:58 +0000
Subject: [PATCH 06/10] Add issue label guidelines for astroid-related issues

Add instructions to check GitHub issue labels and only create regression tests for astroid-related issues that cannot be fixed from this repository.

Co-authored-by: Pierre-Sassoulas <5493666+Pierre-Sassoulas@users.noreply.github.com>
---
 .github/copilot-instructions.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 252bc242ff..87ba29b56f 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -4,6 +4,15 @@ Always follow these instructions first and fallback to additional search and con
 gathering only if the information in these instructions is incomplete or found to be in
 error.
 
+## Issue Label Guidelines
+
+Before attempting to fix any issue, check the GitHub issue labels using the GitHub API:
+
+- If an issue is labeled with "Astroid", "Needs astroid update", "Needs astroid constraint", or "Needs astroid Brain 🧠", **ONLY** create regression tests
+- Do **NOT** attempt to fix astroid-related issues as you cannot modify astroid from this repository
+- For astroid-related issues, focus on creating comprehensive regression tests that reproduce the problem
+- All other issues can be fixed normally following the standard development workflow
+
 ## Development Environment Setup
 
 ### Basic Installation

From b03a498ba38f58e42eca05bc0abac1ec1099c875 Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Fri, 29 Aug 2025 10:15:22 +0200
Subject: [PATCH 07/10] Re-apply "Add dependency groups to pyproject.toml file"
 (#10523)

This reverts commit d462809df4c3b78f4f656a3d5f9249708d4af61f from #10342 who itself reverted #10332
---
 pyproject.toml | 43 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index d16b274573..39293df7f4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,8 @@ classifiers = [
   "Typing :: Typed",
 ]
 dynamic = [ "version" ]
-
+# All the dependencies of the project will be configured here, once pip fully supports PEP735
+# TODO: Remove all requirements.txt files and use this section instead once pip supports PEP735
 dependencies = [
   # Also upgrade requirements_test_min.txt.
   # Pinned to dev of second minor update to allow editable installs and fix primer issues,
@@ -50,8 +51,10 @@ dependencies = [
   "tomlkit>=0.10.1",
   "typing-extensions>=3.10; python_version<'3.10'",
 ]
+
 optional-dependencies.spelling = [ "pyenchant~=3.2" ]
 optional-dependencies.testutils = [ "gitpython>3" ]
+
 urls."Bug Tracker" = "https://github.com/pylint-dev/pylint/issues"
 urls."Discord Server" = "https://discord.com/invite/Egy6P8AMB5"
 urls."Docs: Contributor Guide" = "https://pylint.readthedocs.io/en/latest/development_guide/contributor_guide/index.html"
@@ -64,6 +67,44 @@ scripts.pylint-config = "pylint:_run_pylint_config"
 scripts.pyreverse = "pylint:run_pyreverse"
 scripts.symilar = "pylint:run_symilar"
 
+[dependency-groups]
+dev = [
+  "contributors-txt>=1",
+  "pre-commit",
+  "tbump~=6.11.0",
+]
+
+test = [
+  "coverage~=7.8",
+  "pytest-cov~=6.0",
+  "pytest-xdist~=3.6",
+  "six",
+  "tox>=3",
+  "types-setuptools==78.1.0.20250329",
+  { include-group = "test-min" },
+]
+
+docs = [
+  "furo==2024.8.6",
+  "sphinx==8.2.3",
+  "sphinx-reredirects<1",
+  "towncrier~=24.8",
+]
+
+# Configuration for the build system
+test-min = [
+  # Base test dependencies
+  "astroid==4.0.0a0",                   # Pinned to a specific version for tests
+  "py~=1.11.0",
+  "pytest~=8.3",
+  "pytest-benchmark~=5.1",
+  "pytest-timeout~=2.3",
+  "requests",
+  "setuptools; python_version>='3.12'",
+  "towncrier~=24.8",
+  "typing-extensions~=4.12",
+]
+
 [tool.setuptools.packages.find]
 include = [ "pylint*" ]
 

From 5a1efed83d72ffdb1860c8ccaf4c0571a0d82078 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 Aug 2025 15:09:50 +0000
Subject: [PATCH 08/10] Initial plan


From f1118b39230f0c80de98324ff76551e09db76fff Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Fri, 29 Aug 2025 10:57:23 +0200
Subject: [PATCH 09/10] pre-commit

---
 .github/copilot-instructions.md | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 87ba29b56f..95454b3644 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -8,9 +8,12 @@ error.
 
 Before attempting to fix any issue, check the GitHub issue labels using the GitHub API:
 
-- If an issue is labeled with "Astroid", "Needs astroid update", "Needs astroid constraint", or "Needs astroid Brain 🧠", **ONLY** create regression tests
-- Do **NOT** attempt to fix astroid-related issues as you cannot modify astroid from this repository
-- For astroid-related issues, focus on creating comprehensive regression tests that reproduce the problem
+- If an issue is labeled with "Astroid", "Needs astroid update", "Needs astroid
+  constraint", or "Needs astroid Brain 🧠", **ONLY** create regression tests
+- Do **NOT** attempt to fix astroid-related issues as you cannot modify astroid from
+  this repository
+- For astroid-related issues, focus on creating comprehensive regression tests that
+  reproduce the problem
 - All other issues can be fixed normally following the standard development workflow
 
 ## Development Environment Setup

From b95244fdf528ef5bb61e723ae6ee75a464720960 Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Fri, 29 Aug 2025 11:53:07 +0200
Subject: [PATCH 10/10] pre-commit

---
 .github/copilot-instructions.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 95454b3644..0f9a0eead9 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -24,7 +24,6 @@ Clone and set up pylint development environment:
 
 - `git clone https://github.com/pylint-dev/pylint` -- clone repository
 - `cd pylint` -- enter directory
-- `python3 --version` -- verify Python 3.8+ is available (development requires 3.8+)
 - `python3 -m venv venv` -- create virtual environment
 - `source venv/bin/activate` -- activate virtual environment (Linux/Mac)
 - `pip install -r requirements_test_min.txt` -- install test dependencies (~30 seconds)
@@ -217,6 +216,7 @@ script/                   # Development utility scripts
 - Write comprehensive commit messages relating to tracker issues
 - Keep changes small and separate consensual from opinionated changes
 - Add news fragment: `towncrier create <IssueNumber>.<type>`
+- Always launch `pre-commit run -a` before committing
 
 ### Documentation Changes