Add client side configuration and cache configuration per file

.gitignore

@@ -2,6 +2,7 @@
 .mypy_cache
 *.egg-info
 *.pyc
+*.orig
 .pytest_cache
 .ropeproject
 build

README.md

@@ -21,8 +21,31 @@ To avoid unexpected results you should make sure `yapf` and `autopep8` are not i
 - The code will only be formatted if it is syntactically valid Python.
 - Text selections are treated as if they were a separate Python file.
   Unfortunately this means you can't format an indented block of code.
-- `python-lsp-black` will use your project's [pyproject.toml](https://github.com/psf/black#pyprojecttoml) if it has one.
-- `python-lsp-black` only officially supports the latest stable version of [black](https://github.com/psf/black). An effort is made to keep backwards-compatibility but older black versions will not be actively tested.
+- `python-lsp-black` will use your project's
+  [pyproject.toml](https://github.com/psf/black#pyprojecttoml) if it has one.
+- `python-lsp-black` only officially supports the latest stable version of
+  [black](https://github.com/psf/black). An effort is made to keep backwards-compatibility
+  but older black versions will not be actively tested.
+- The plugin can cache the black configuration that applies to each Python file, this
+  improves performance of the plugin. When configuration caching is enabled any changes to
+  black's configuration will need the LSP server to be restarted. Configuration caching
+  can be disabled with the `cache_config` option, see *Configuration* below.
+
+# Configuration
+
+The plugin follows [python-lsp-server's
+configuration](https://github.com/python-lsp/python-lsp-server/#configuration). These are
+the valid configuration keys:
+
+- `pylsp.plugins.black.enabled`: boolean to enable/disable the plugin.
+- `pylsp.plugins.black.cache_config`: a boolean to enable black configuration caching (see
+  *Usage*). `false` by default.
+- `pylsp.plugins.black.line_length`: an integer that maps to [black's
+  `max-line-length`](https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#line-length)
+  setting. Defaults to 88 (same as black's default). This can also be set through black's
+  configuration files, which should be preferred for multi-user projects.
+- `pylsp.plugins.black.preview`: a boolean to enable or disable [black's `--preview`
+  setting](https://black.readthedocs.io/en/stable/the_black_code_style/future_style.html#preview-style).
 
 # Development
 
@@ -35,8 +58,8 @@ pip install -e .[dev]
 ```
 
 This project uses [pre-commit](https://pre-commit.com/) hooks to control code quality,
-install them to run them when creating a git commit, thus avoiding seeing errors when you
-create a pull request:
+install them to run automatically when creating a git commit, thus avoiding seeing errors
+when you create a pull request:
 
 ```shell
 pre-commit install

pylsp_black/plugin.py

@@ -1,12 +1,14 @@
 import logging
 import os
+from functools import lru_cache
 from pathlib import Path
 from typing import Dict, Optional
 
 import black
 import toml
 from pylsp import hookimpl
 from pylsp._utils import get_eol_chars
+from pylsp.config.config import Config
 
 logger = logging.getLogger(__name__)
 
@@ -27,19 +29,34 @@
 
 
 @hookimpl(tryfirst=True)
-def pylsp_format_document(document):
-    return format_document(document)
+def pylsp_format_document(config, document):
+    return format_document(config, document)
 
 
 @hookimpl(tryfirst=True)
-def pylsp_format_range(document, range):
+def pylsp_format_range(config, document, range):
     range["start"]["character"] = 0
     range["end"]["line"] += 1
     range["end"]["character"] = 0
-    return format_document(document, range)
+    return format_document(config, document, range)
+
+
+@hookimpl
+def pylsp_settings():
+    """Configuration options that can be set on the client."""
+    return {
+        "plugins": {
+            "black": {
+                "enabled": True,
+                "line_length": 88,
+                "preview": False,
+                "cache_config": False,
+            }
+        }
+    }
 
 
-def format_document(document, range=None):
+def format_document(client_config, document, range=None):
     if range:
         start = range["start"]["line"]
         end = range["end"]["line"]
@@ -51,7 +68,7 @@ def format_document(document, range=None):
             "end": {"line": len(document.lines), "character": 0},
         }
 
-    config = load_config(document.path)
+    config = load_config(document.path, client_config)
 
     try:
         formatted_text = format_text(text=text, config=config)
@@ -103,13 +120,17 @@ def format_text(*, text, config):
         raise black.NothingChanged from e
 
 
-def load_config(filename: str) -> Dict:
+@lru_cache(100)
+def _load_config(filename: str, client_config: Config) -> Dict:
+    settings = client_config.plugin_settings("black")
+
     defaults = {
-        "line_length": 88,
+        "line_length": settings.get("line_length", 88),
         "fast": False,
         "pyi": filename.endswith(".pyi"),
         "skip_string_normalization": False,
         "target_version": set(),
+        "preview": settings.get("preview", False),
     }
 
     root = black.find_project_root((filename,))
@@ -168,3 +189,13 @@ def load_config(filename: str) -> Dict:
     logger.info("Using config from %s: %r", pyproject_filename, config)
 
     return config
+
+
+def load_config(filename: str, client_config: Config) -> Dict:
+    settings = client_config.plugin_settings("black")
+
+    # Use the original, not cached function to load settings if requested
+    if not settings.get("cache_config", False):
+        return _load_config.__wrapped__(filename, client_config)
+
+    return _load_config(filename, client_config)

setup.cfg

@@ -18,7 +18,7 @@ classifiers =
 
 [options]
 packages = find:
-install_requires = python-lsp-server>=1.4.0; black>=19.3b0; toml
+install_requires = python-lsp-server>=1.4.0; black>=22.1.0; toml
 python_requires = >= 3.7
 
 [options.entry_points]

tests/fixtures/formatted-line-length.py

@@ -0,0 +1,4 @@
+def foo(
+    aaaaa, bbbbb, ccccc, ddddd, eeeee, fffff, ggggg, hhhhh, iiiii, jjjjj, kkkkk
+):
+    return aaaaa  # noqa

tests/fixtures/unformatted-line-length.py

@@ -0,0 +1,3 @@
+
+def foo(aaaaa, bbbbb, ccccc, ddddd, eeeee, fffff, ggggg, hhhhh, iiiii, jjjjj, kkkkk):
+    return aaaaa  # noqa