Implement pre-commit hooks.

Author: owenlittlejohns

.pre-commit-config.yaml

@@ -1,19 +1,19 @@
-# See https://pre-commit.com for more information
-# See https://pre-commit.com/hooks.html for more hooks
 repos:
-- repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.4.0
-  hooks:
-    - id: trailing-whitespace
-    - id: end-of-file-fixer
-    - id: check-yaml
-    - id: check-added-large-files
-- repo: https://github.com/akaihola/darker
-  rev: 1.7.2
-  hooks:
-    - id: darker
-      args:
-        - --isort
-        - --skip-string-normalization
-      additional_dependencies:
-        - isort~=5.13.1
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.2.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-json
+      - id: check-yaml
+      - id: check-added-large-files
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.3.4
+    hooks:
+      - id: ruff
+        args: ["--fix", "--show-fixes"]
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 24.3.0
+    hooks:
+      - id: black-jupyter
+        language_version: python3.11

README.md

@@ -140,6 +140,39 @@ newest relate of the code (starting at the top of the file).
 ## vX.Y.Z
 ```
 
+### pre-commit hooks:
+
+This repository uses [pre-commit](https://pre-commit.com/) to enable pre-commit
+checking the repository for some coding standard best practices. These include:
+
+* Removing trailing whitespaces.
+* Removing blank lines at the end of a file.
+* JSON files have valid formats.
+* [ruff](https://github.com/astral-sh/ruff) Python linting checks.
+* [black](https://black.readthedocs.io/en/stable/index.html) Python code
+  formatting checks.
+
+To enable these checks:
+
+```bash
+# Install pre-commit Python package as part of test requirements:
+pip install -r tests/pip_test_requirements.txt
+
+# Install the git hook scripts:
+pre-commit install
+
+# (Optional) Run against all files:
+pre-commit run --all-files
+```
+
+When you try to make a new commit locally, `pre-commit` will automatically run.
+If any of the hooks detect non-compliance (e.g., trailing whitespace), that
+hook will state it failed, and also try to fix the issue. You will need to
+review and `git add` the changes before you can make a commit.
+
+It is planned to implement additional hooks, possibly including tools such as
+`mypy`.
+
 ## Releasing a new version of the service:
 
 Once a new Docker image has been published with a new semantic version tag,

tests/unit/test_adapter.py

@@ -1,4 +1,4 @@
-from unittest import TestCase, skip
+from unittest import TestCase
 
 from harmony.message import Message
 from harmony.util import config