pre-commit hooks demo

.codespellignore

@@ -0,0 +1,3 @@
+connectd
+crate
+mut

.codespellrc

@@ -0,0 +1,4 @@
+[codespell]
+
+count = true
+ignore-words = .codespellignore

.pre-commit-config.yaml

@@ -11,3 +11,63 @@ repos:
     - id: ruff-format
       args: [ --diff ]
       exclude: "contrib/pyln-grpc-proto/pyln/grpc/(primitives|node)_pb2(|_grpc).py"
+
+- repo: https://github.com/shellcheck-py/shellcheck-py
+  rev: v0.11.0.1
+  hooks:
+    - id: shellcheck
+      args: [ -fgcc ]
+
+- repo: https://github.com/python-jsonschema/check-jsonschema
+  rev: 0.30.0
+  hooks:
+    - id: check-jsonschema
+      name: check doc JSON schemas
+      args: ["--schemafile", "doc/rpc-schema-draft.json"]
+      files: ^doc/schemas/.*\.json$
+      types: [ json ]
+
+    - id: check-metaschema
+      name: check doc JSON metaschemas
+      args: ["--verbose"]
+      files: ^doc/schemas/.*\.json$
+      types: [ json ]
+
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v5.0.0
+  hooks:
+    - id: pretty-format-json
+      args: [ "--indent", "2", "--no-sort-keys" ]
+      files: ^doc/schemas/.*\.json$
+      types: [ json ]
+    - id: trailing-whitespace
+      args: [ "--markdown-linebreak-ext=md" ]
+      exclude: ccan|contrib|tests/fuzz/corpora
+    - id: end-of-file-fixer
+      exclude: ccan|contrib|tests/fuzz/corpora
+
+- repo: https://github.com/codespell-project/codespell
+  rev: v2.3.0
+  hooks:
+    - id: codespell
+      description: Checks for common misspellings.
+      exclude: ccan|contrib|tests/fuzz/corpora
+
+- repo: local
+  hooks:
+    # Reimplementation of `make check-amount-access` for pygrep.
+    - id: check-amount-access
+      name: Check amount_msat and amount_sat members are not accessed directly
+      description: "Don't access amount_msat and amount_sat members directly without a good reason since it risks overflow."
+      language: pygrep
+      entry: (->|\.)(milli)?satoshis(?!.*\/\*\ Raw:)|(?<!sizeof)\(struct\ amount_(m)?sat\)
+      types: [ c ]
+      exclude: common/amount|.*/test/.*
+
+    # Reimplementation of `make check-discouraged-functions` for pygrep.
+    - id: check-discouraged-functions
+      name: Check for usage of discouraged funtions
+      language: pygrep
+      entry: '[^a-z_/](?:fgets|fputs|gets|scanf|sprintf)\('
+      types: [ c ]
+      exclude: ccan|contrib

doc/contribute-to-core-lightning/contributor-workflow.md

@@ -61,6 +61,19 @@ uv build contrib/pyln-client/
 uv build contrib/pyln-proto/
 ```
 
+## Local checks with pre-commit
+
+You can avoid common mistakes, speed up your development workflow and avoid wasteful CI runs by opting in to the local code checks managed by [pre-commit](https://pre-commit.com). The `pre-commit` Python package is part of the `dev` group and should be installed along with the other packages using `pip` or `uv` when [installing from source](https://docs.corelightning.org/docs/installation#installing-from-source). Activate it on your local development environment from the root of your Core Lightning working directory with:
+```shell
+pre-commit install
+```
+
+You can disable and remove it with:
+```shell
+pre-commit uninstall
+pre-commit clean
+```
+
 ## Making BOLT Modifications
 
 All of code for marshalling/unmarshalling BOLT protocol messages is generated directly from the spec. These are pegged to the BOLTVERSION, as specified in `Makefile`.

pyproject.toml

@@ -36,6 +36,7 @@ dev = [
   "tqdm",
   "pytest-benchmark",
   "pdoc3>=0.11.6",
+  "pre-commit>=4.3.0",
 ]
 
 [project.optional-dependencies]

tools/fix-style-errors

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Takes a list of files and applies style fixes for Python using `ruff` and C using
+# `clang-format`. Also corrects spelling using `codespell`. This tool is an auxiliary to the
+# `pre-commit` hooks found in:
+#   `.pre-commit-config.yaml`
+#
+# WARNING: Changes are destructive. Ensure a clean working environment before running.
+#
+# By: @sangbida
+
+for file in "$@"; do
+    case "$file" in
+        *.py)  ruff check --fix "$file"; ruff format "$file" ;;
+        *.c|*.h)  clang-format -i "$file" 2>/dev/null ;;
+    esac
+    codespell -w "$file" 2>/dev/null
+done