ci: adding Conventional Commits linting (#10)

* https://www.conventionalcommits.org/en/v1.0.0/

.github/workflows/conventional-commits.yml

@@ -0,0 +1,22 @@
+name: Conventional Commits
+
+on: pull_request
+
+env:
+  # Forcing Earthly to use colours, to make reading output easier.
+  FORCE_COLOR: 1
+
+jobs:
+  linting:
+    name: Linting
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download Earthly v0.8.1.
+        run: "sudo /bin/sh -c 'wget https://github.com/earthly/earthly/releases/download/v0.8.1/earthly-linux-amd64 -O /usr/local/bin/earthly && chmod +x /usr/local/bin/earthly'"
+      - name: Checkout code.
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 0
+      - name: Check Conventional Commits linting.
+        run: earthly --ci +check-conventional-commits-linting --from_reference "origin/${{ github.base_ref }}"

Earthfile

@@ -25,6 +25,14 @@ check-clean-git-history:
     RUN ./ci/check-clean-git-history.sh --from-reference "${from_reference}"
 
 
+check-conventional-commits-linting:
+    FROM +rust-base
+    RUN cargo install conventional_commits_linter --version 0.12.3
+    DO +COPY_METADATA
+    ARG from_reference="origin/HEAD"
+    RUN ./ci/check-conventional-commits-linting.sh --from-reference "${from_reference}"
+
+
 golang-base:
     FROM golang:1.20.4
     ENV GOPROXY=direct

ci/check-conventional-commits-linting.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+
+# ARG_OPTIONAL_SINGLE([from-reference],[],[],[origin/HEAD])
+# ARGBASH_GO()
+# needed because of Argbash --> m4_ignore([
+### START OF CODE GENERATED BY Argbash v2.9.0 one line above ###
+# Argbash is a bash code generator used to get arguments parsing right.
+# Argbash is FREE SOFTWARE, see https://argbash.io for more info
+# Generated online by https://argbash.io/generate
+
+die() {
+	local _ret="${2:-1}"
+	test "${_PRINT_HELP:-no}" = yes && print_help >&2
+	echo "$1" >&2
+	exit "${_ret}"
+}
+
+begins_with_short_option() {
+	local first_option all_short_options=''
+	first_option="${1:0:1}"
+	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
+}
+
+# THE DEFAULTS INITIALIZATION - OPTIONALS
+_arg_from_reference="origin/HEAD"
+
+print_help() {
+	printf 'Usage: %s [--from-reference <arg>]\n' "$0"
+}
+
+parse_commandline() {
+	while test $# -gt 0; do
+		_key="$1"
+		case "$_key" in
+		--from-reference)
+			test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+			_arg_from_reference="$2"
+			shift
+			;;
+		--from-reference=*)
+			_arg_from_reference="${_key##--from-reference=}"
+			;;
+		*)
+			_PRINT_HELP=yes die "FATAL ERROR: Got an unexpected argument '$1'" 1
+			;;
+		esac
+		shift
+	done
+}
+
+parse_commandline "$@"
+
+# OTHER STUFF GENERATED BY Argbash
+
+### END OF CODE GENERATED BY Argbash (sortof) ### ])
+# [ <-- needed because of Argbash
+set -o errexit
+set -o xtrace
+
+"${CARGO_HOME}/bin/conventional_commits_linter" --from-reference "${_arg_from_reference}" --allow-angular-type-only
+# ] <-- needed because of Argbash