ci: spell-check the code as part of linting (#1388)

Add a `codespell` run as part of the `tox -e lint` environment, to pick
up any spelling errors that might be missed in review. It's also added
to the pre-commit checks, for anyone using those.

The PR also makes 4 corrections, which codespell found. Two are
debatable (whether or not to hyphenate) but two are definite errors.

This adds a new (lint-time) dependency of codespell - it's also used in
the default charmcraft profile, I've used it before, and it has a [good
Snyk score](https://snyk.io/advisor/python/codespell) so it seems ok to
me. I have lightly skimmed the code, but not read it in depth.

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v4.5.0
     hooks:
       - id: check-added-large-files
       - id: check-ast
@@ -24,3 +24,10 @@ repos:
         args: [ --preview ]
       - id: ruff-format
         args: [ --preview ]
+  # Spellcheck the code.
+  - repo: https://github.com/codespell-project/codespell
+    rev: v2.2.4
+    hooks:
+    - id: codespell
+      additional_dependencies:
+        - tomli

CODE_OF_CONDUCT.md

@@ -6,7 +6,7 @@ In the interest of fostering an open and welcoming environment, we as
 contributors and maintainers pledge to making participation in our project and
 our community a harassment-free experience for everyone, regardless of age, body
 size, disability, ethnicity, sex characteristics, gender identity and expression,
-level of experience, education, socio-economic status, nationality, personal
+level of experience, education, socioeconomic status, nationality, personal
 appearance, race, religion, or sexual identity and orientation.
 
 ## Our Standards

ops/_private/harness.py

@@ -380,7 +380,7 @@ def begin(self) -> None:
         if self._charm is not None:
             raise RuntimeError('cannot call the begin method on the harness more than once')
 
-        # The Framework adds attributes to class objects for events, etc. As such, we can't re-use
+        # The Framework adds attributes to class objects for events, etc. As such, we can't reuse
         # the original class against multiple Frameworks. So create a locally defined class
         # and register it.
         # TODO: jam 2020-03-16 We are looking to changes this to Instance attributes instead of

ops/model.py

@@ -3133,7 +3133,7 @@ def _format_action_result_dict(
     parent_key: Optional[str] = None,
     output: Optional[Dict[str, str]] = None,
 ) -> Dict[str, str]:
-    """Turn a nested dictionary into a flattened dictionary, using '.' as a key seperator.
+    """Turn a nested dictionary into a flattened dictionary, using '.' as a key separator.
 
     This is used to allow nested dictionaries to be translated into the dotted format required by
     the Juju `action-set` hook tool in order to set nested data on an action.
@@ -3973,7 +3973,7 @@ class CloudSpec:
     """A list of CA certificates."""
 
     skip_tls_verify: bool = False
-    """Whether to skip TLS verfication."""
+    """Whether to skip TLS verification."""
 
     is_controller_cloud: bool = False
     """If this is the cloud used by the controller, defaults to False."""

pyproject.toml

@@ -224,3 +224,7 @@ reportUnnecessaryComparison = false
 reportUnnecessaryTypeIgnoreComment = "error"
 disableBytesTypePromotions = false
 stubPath = ""
+
+[tool.codespell]
+skip = './docs/_build,.venv,venv,build'
+quiet-level = 3

tox.ini

@@ -68,9 +68,11 @@ commands =
 description = Check code against coding style standards
 deps =
     ruff==0.4.5
+    codespell==2.3.0
 commands =
     ruff check --preview
     ruff format --preview --check
+    codespell
 
 [testenv:static]
 description = Run static type checker