setup isort & black, introduce pre-commit

.github/workflows/static.yml

@@ -35,13 +35,10 @@ jobs:
           python-version: '3.7'
           architecture: 'x64'
       - run: python -m pip install --upgrade pip setuptools jsonschema
-      - run: pip install -e .[pylint,pycodestyle,pyflakes]
-      - name: Pylint checks
-        run: pylint pylsp test
-      - name: Code style checks
-        run: pycodestyle pylsp test
-      - name: Pyflakes checks
-        run: pyflakes pylsp test
+      - run: pip install -e .[lint]
+      - name: run linters via pre-commit
+        run: |
+          pre-commit run --all --show-diff-on-failure --color=always
       - name: Validate JSON schema
         run: echo {} | jsonschema pylsp/config/schema.json
       - name: Ensure JSON schema and Markdown docs are in sync

.pre-commit-config.yaml

@@ -0,0 +1,33 @@
+repos:
+-   repo: local
+    hooks:
+    -   id: isort
+        name: isort
+        entry: isort
+        language: system
+        types:
+        - python
+    -   id: black
+        name: black
+        entry: black
+        language: system
+        types:
+        - python
+    -   id: pyflakes
+        name: pyflakes
+        entry: pyflakes
+        language: system
+        types:
+        - python
+    -   id: pylint
+        name: pylint
+        entry: pylint
+        language: system
+        types:
+        - python
+    -   id: pycodestyle
+        name: pycodestyle
+        entry: pycodestyle
+        language: system
+        types:
+        - python

README.md

@@ -161,6 +161,13 @@ To run the test suite:
 pip install ".[test]" && pytest
 ```
 
+To run the linters: 
+```sh 
+pip install ".[lint]" && pre-commit run --all
+```
+You can also locally run `pre-commit install` in your repo to run 
+linters on changed files when committing.
+
 After adding configuration options to `schema.json`, refresh the `CONFIGURATION.md` file with
 
 ```

pylsp/__init__.py

@@ -2,7 +2,9 @@
 # Copyright 2021- Python Language Server Contributors.
 
 import os
+
 import pluggy
+
 from . import _version
 from ._version import __version__
 
@@ -22,8 +24,8 @@ def convert_version_info(version: str) -> (int, ..., str):
 
 _version.VERSION_INFO = convert_version_info(__version__)
 
-PYLSP = 'pylsp'
-IS_WIN = os.name == 'nt'
+PYLSP = "pylsp"
+IS_WIN = os.name == "nt"
 
 hookspec = pluggy.HookspecMarker(PYLSP)
 hookimpl = pluggy.HookimplMarker(PYLSP)

pylsp/__main__.py

@@ -12,59 +12,39 @@
 except Exception:  # pylint: disable=broad-except
     import json
 
-from .python_lsp import (PythonLSPServer, start_io_lang_server,
-                         start_tcp_lang_server, start_ws_lang_server)
 from ._version import __version__
+from .python_lsp import PythonLSPServer, start_io_lang_server, start_tcp_lang_server, start_ws_lang_server
 
-LOG_FORMAT = "%(asctime)s {0} - %(levelname)s - %(name)s - %(message)s".format(
-    time.localtime().tm_zone)
+LOG_FORMAT = "%(asctime)s {0} - %(levelname)s - %(name)s - %(message)s".format(time.localtime().tm_zone)
 
 
 def add_arguments(parser):
     parser.description = "Python Language Server"
 
+    parser.add_argument("--tcp", action="store_true", help="Use TCP server instead of stdio")
+    parser.add_argument("--ws", action="store_true", help="Use Web Sockets server instead of stdio")
+    parser.add_argument("--host", default="127.0.0.1", help="Bind to this address")
+    parser.add_argument("--port", type=int, default=2087, help="Bind to this port")
     parser.add_argument(
-        "--tcp", action="store_true",
-        help="Use TCP server instead of stdio"
-    )
-    parser.add_argument(
-        "--ws", action="store_true",
-        help="Use Web Sockets server instead of stdio"
-    )
-    parser.add_argument(
-        "--host", default="127.0.0.1",
-        help="Bind to this address"
-    )
-    parser.add_argument(
-        "--port", type=int, default=2087,
-        help="Bind to this port"
-    )
-    parser.add_argument(
-        '--check-parent-process', action="store_true",
+        "--check-parent-process",
+        action="store_true",
         help="Check whether parent process is still alive using os.kill(ppid, 0) "
         "and auto shut down language server process when parent process is not alive."
-        "Note that this may not work on a Windows machine."
+        "Note that this may not work on a Windows machine.",
     )
 
     log_group = parser.add_mutually_exclusive_group()
-    log_group.add_argument(
-        "--log-config",
-        help="Path to a JSON file containing Python logging config."
-    )
+    log_group.add_argument("--log-config", help="Path to a JSON file containing Python logging config.")
     log_group.add_argument(
         "--log-file",
-        help="Redirect logs to the given file instead of writing to stderr."
-        "Has no effect if used with --log-config."
+        help="Redirect logs to the given file instead of writing to stderr." "Has no effect if used with --log-config.",
     )
 
     parser.add_argument(
-        '-v', '--verbose', action='count', default=0,
-        help="Increase verbosity of log output, overrides log config file"
+        "-v", "--verbose", action="count", default=0, help="Increase verbosity of log output, overrides log config file"
     )
 
-    parser.add_argument(
-        '-V', '--version', action='version', version='%(prog)s v' + __version__
-    )
+    parser.add_argument("-V", "--version", action="version", version="%(prog)s v" + __version__)
 
 
 def main():
@@ -74,15 +54,12 @@ def main():
     _configure_logger(args.verbose, args.log_config, args.log_file)
 
     if args.tcp:
-        start_tcp_lang_server(args.host, args.port, args.check_parent_process,
-                              PythonLSPServer)
+        start_tcp_lang_server(args.host, args.port, args.check_parent_process, PythonLSPServer)
     elif args.ws:
-        start_ws_lang_server(args.port, args.check_parent_process,
-                             PythonLSPServer)
+        start_ws_lang_server(args.port, args.check_parent_process, PythonLSPServer)
     else:
         stdin, stdout = _binary_stdio()
-        start_io_lang_server(stdin, stdout, args.check_parent_process,
-                             PythonLSPServer)
+        start_io_lang_server(stdin, stdout, args.check_parent_process, PythonLSPServer)
 
 
 def _binary_stdio():
@@ -99,14 +76,13 @@ def _configure_logger(verbose=0, log_config=None, log_file=None):
     root_logger = logging.root
 
     if log_config:
-        with open(log_config, 'r', encoding='utf-8') as f:
+        with open(log_config, "r", encoding="utf-8") as f:
             logging.config.dictConfig(json.load(f))
     else:
         formatter = logging.Formatter(LOG_FORMAT)
         if log_file:
             log_handler = logging.handlers.RotatingFileHandler(
-                log_file, mode='a', maxBytes=50*1024*1024,
-                backupCount=10, encoding=None, delay=0
+                log_file, mode="a", maxBytes=50 * 1024 * 1024, backupCount=10, encoding=None, delay=0
             )
         else:
             log_handler = logging.StreamHandler()
@@ -123,5 +99,5 @@ def _configure_logger(verbose=0, log_config=None, log_file=None):
     root_logger.setLevel(level)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()

pylsp/_utils.py

@@ -17,14 +17,15 @@
 
 # Eol chars accepted by the LSP protocol
 # the ordering affects performance
-EOL_CHARS = ['\r\n', '\r', '\n']
+EOL_CHARS = ["\r\n", "\r", "\n"]
 EOL_REGEX = re.compile(f'({"|".join(EOL_CHARS)})')
 
 log = logging.getLogger(__name__)
 
 
 def debounce(interval_s, keyed_by=None):
     """Debounce calls to this function until interval_s seconds have passed."""
+
     def wrapper(func):
         timers = {}
         lock = threading.Lock()
@@ -48,7 +49,9 @@ def run():
                 timer = threading.Timer(interval_s, run)
                 timers[key] = timer
                 timer.start()
+
         return debounced
+
     return wrapper
 
 
@@ -92,11 +95,11 @@ def path_to_dot_name(path):
     directory = os.path.dirname(path)
     module_name, _ = os.path.splitext(os.path.basename(path))
     full_name = [module_name]
-    while os.path.exists(os.path.join(directory, '__init__.py')):
+    while os.path.exists(os.path.join(directory, "__init__.py")):
         this_directory = os.path.basename(directory)
         directory = os.path.dirname(directory)
         full_name = [this_directory] + full_name
-    return '.'.join(full_name)
+    return ".".join(full_name)
 
 
 def match_uri_to_workspace(uri, workspaces):
@@ -128,6 +131,7 @@ def merge_dicts(dict_a, dict_b):
 
     If override_nones is True, then
     """
+
     def _merge_dicts_(a, b):
         for key in set(a.keys()).union(b.keys()):
             if key in a and key in b:
@@ -143,15 +147,16 @@ def _merge_dicts_(a, b):
                 yield (key, a[key])
             elif b[key] is not None:
                 yield (key, b[key])
+
     return dict(_merge_dicts_(dict_a, dict_b))
 
 
 def escape_plain_text(contents: str) -> str:
     """
     Format plain text to display nicely in environments which do not respect whitespaces.
     """
-    contents = contents.replace('\t', '\u00A0' * 4)
-    contents = contents.replace('  ', '\u00A0' * 2)
+    contents = contents.replace("\t", "\u00A0" * 4)
+    contents = contents.replace("  ", "\u00A0" * 2)
     return contents
 
 
@@ -160,17 +165,17 @@ def escape_markdown(contents: str) -> str:
     Format plain text to display nicely in Markdown environment.
     """
     # escape markdown syntax
-    contents = re.sub(r'([\\*_#[\]])', r'\\\1', contents)
+    contents = re.sub(r"([\\*_#[\]])", r"\\\1", contents)
     # preserve white space characters
     contents = escape_plain_text(contents)
     return contents
 
 
 def wrap_signature(signature):
-    return '```python\n' + signature + '\n```\n'
+    return "```python\n" + signature + "\n```\n"
 
 
-SERVER_SUPPORTED_MARKUP_KINDS = {'markdown', 'plaintext'}
+SERVER_SUPPORTED_MARKUP_KINDS = {"markdown", "plaintext"}
 
 
 def choose_markup_kind(client_supported_markup_kinds: List[str]):
@@ -181,7 +186,7 @@ def choose_markup_kind(client_supported_markup_kinds: List[str]):
     for kind in client_supported_markup_kinds:
         if kind in SERVER_SUPPORTED_MARKUP_KINDS:
             return kind
-    return 'markdown'
+    return "markdown"
 
 
 def format_docstring(contents: str, markup_kind: str, signatures: Optional[List[str]] = None):
@@ -195,33 +200,24 @@ def format_docstring(contents: str, markup_kind: str, signatures: Optional[List[
     to the provided contents of the docstring if given.
     """
     if not isinstance(contents, str):
-        contents = ''
+        contents = ""
 
-    if markup_kind == 'markdown':
+    if markup_kind == "markdown":
         try:
             value = docstring_to_markdown.convert(contents)
-            return {
-                'kind': 'markdown',
-                'value': value
-            }
+            return {"kind": "markdown", "value": value}
         except docstring_to_markdown.UnknownFormatError:
             # try to escape the Markdown syntax instead:
             value = escape_markdown(contents)
 
         if signatures:
-            value = wrap_signature('\n'.join(signatures)) + '\n\n' + value
+            value = wrap_signature("\n".join(signatures)) + "\n\n" + value
 
-        return {
-            'kind': 'markdown',
-            'value': value
-        }
+        return {"kind": "markdown", "value": value}
     value = contents
     if signatures:
-        value = '\n'.join(signatures) + '\n\n' + value
-    return {
-        'kind': 'plaintext',
-        'value': escape_plain_text(value)
-    }
+        value = "\n".join(signatures) + "\n\n" + value
+    return {"kind": "plaintext", "value": escape_plain_text(value)}
 
 
 def clip_column(column, lines, line_number):
@@ -230,7 +226,7 @@ def clip_column(column, lines, line_number):
 
     https://microsoft.github.io/language-server-protocol/specification#position
     """
-    max_column = len(lines[line_number].rstrip('\r\n')) if len(lines) > line_number else 0
+    max_column = len(lines[line_number].rstrip("\r\n")) if len(lines) > line_number else 0
     return min(column, max_column)
 
 
@@ -242,14 +238,14 @@ def position_to_jedi_linecolumn(document, position):
     """
     code_position = {}
     if position:
-        code_position = {'line': position['line'] + 1,
-                         'column': clip_column(position['character'],
-                                               document.lines,
-                                               position['line'])}
+        code_position = {
+            "line": position["line"] + 1,
+            "column": clip_column(position["character"], document.lines, position["line"]),
+        }
     return code_position
 
 
-if os.name == 'nt':
+if os.name == "nt":
     import ctypes
 
     kernel32 = ctypes.windll.kernel32