feat: add pre-conventional-commit hook

Author: Atiqur Rahman

scripts/conventional-pre-commit.sh

@@ -1,13 +1,52 @@
 #!/usr/bin/env bash
 
-if ! grep -qE "^\bbuild\b|\bchore\b|\bci\b|\bdocs\b|\bfeat\b|\bfix\b|\bperf\b|\brefactor\b|\brevert\b|\bstyle\b|\btest\b(\([a-z ]+\)!)?: [\w ]+$" "$1"; then
-    cat $1
-    echo "
-Your commit message doesn't conform to Convential Commit Rules (https://www.conventionalcommits.org/).
-At a minimum, your commit should start with one of the below keywords:
-build: chore: ci: docs: feat: fix: perf: refactor: revert: style: test:
-Example commit message to add a feature: 'feat: Changed something to add a lovely new feature'
-Example commit message to fix an issue: 'fix: Removed infinite loop causing that annoying bug'
+# list of Conventional Commits types
+cc_types=("feat" "fix")
+default_types=("build" "chore" "ci" "docs" "${cc_types[@]}" "perf" "refactor" "revert" "style" "test")
+types=( "${cc_types[@]}" )
+
+if [ $# -eq 1 ]; then
+    types=( "${default_types[@]}" )
+else
+    # assume all args but the last are types
+    while [ $# -gt 1 ]; do
+        types+=( "$1" )
+        shift
+    done
+fi
+
+# the commit message file is the last remaining arg
+msg_file="$1"
+
+# join types with | to form regex ORs
+r_types="($(IFS='|'; echo "${types[*]}"))"
+# optional (scope)
+r_scope="(\([[:alnum:] \/-]+\))?"
+# optional breaking change indicator and colon delimiter
+r_delim='!?:'
+# subject line, body, footer
+r_subject=" [[:alnum:]].+"
+# the full regex pattern
+pattern="^$r_types$r_scope$r_delim$r_subject$"
+merge_msg_regex="^Merge branch '.+'\$"
+
+# Check if commit is conventional commit
+if grep -Eq "$pattern|$merge_msg_regex" "$msg_file"; then
+    exit 0
+fi
+
+echo "[Commit message] $( cat "$msg_file" )"
+echo "
+Your commit message does not follow Conventional Commits formatting
+https://www.conventionalcommits.org/
+Conventional Commits start with one of the below types, followed by a colon,
+followed by the commit message:
+    $(IFS=' '; echo "${types[*]}")
+Example commit message adding a feature:
+    feat: implement new API
+Example commit message fixing an issue:
+    fix: remove infinite loop
+Optionally, include a scope in parentheses after the type for more context:
+    fix(account): remove infinite loop
 "
-    exit 1
-fi
+exit 1