Add alpha formatter support (#50)

.pre-commit-hooks.yaml

@@ -1,10 +1,20 @@
--   id: ruff
-    name: ruff
-    description: "Run 'ruff' for extremely fast Python linting"
-    entry: ruff check --force-exclude
-    language: python
-    'types_or': [python, pyi]
-    args: []
-    require_serial: true
-    additional_dependencies: []
-    minimum_pre_commit_version: '2.9.2'
+- id: ruff
+  name: ruff
+  description: "Run 'ruff' for extremely fast Python linting"
+  entry: ruff check --force-exclude
+  language: python
+  "types_or": [python, pyi]
+  args: []
+  require_serial: true
+  additional_dependencies: []
+  minimum_pre_commit_version: "2.9.2"
+- id: ruff-format
+  name: ruff-format
+  description: "Run 'ruff format' for extremely fast Python formatting"
+  entry: ruff format --force-exclude
+  language: python
+  "types_or": [python, pyi]
+  args: []
+  require_serial: true
+  additional_dependencies: []
+  minimum_pre_commit_version: "2.9.2"

README.md

@@ -50,6 +50,28 @@ _unless_ you enable autofix, in which case, Ruff's pre-commit hook should run _b
 and other formatting tools, as Ruff's autofix behavior can output code changes that require
 reformatting.
 
+### Using Ruff's formatter (unstable)
+
+[Ruff's formatter](https://github.com/astral-sh/ruff/blob/main/crates/ruff_python_formatter/README.md) is in Alpha, but can used with pre-commit by adding the `ruff-format` hook:
+
+```yaml
+- repo: https://github.com/astral-sh/ruff-pre-commit
+  rev: v0.0.289
+  hooks:
+    - id: ruff-format
+```
+
+To check formatting without changing files, use `--check`:
+
+```yaml
+- repo: https://github.com/astral-sh/ruff-pre-commit
+  # Ruff version.
+  rev: v0.0.289
+  hooks:
+    - id: ruff-format
+      args: [--check]
+```
+
 ## License
 
 MIT