feat: add conventional-pre-commit hook

Author: Atiqur Rahman

detekt.gradle

@@ -17,3 +17,15 @@ task createDetektPreCommitHook() {
 """
     "chmod +x .git/hooks/pre-commit".execute()
 }
+
+task createConventionalMessagePreCommitHook() {
+    def gitHooksDirectory = new File("$project.rootDir/.git/hooks/")
+    if (!gitHooksDirectory.exists()) gitHooksDirectory.mkdirs()
+    new File("$project.rootDir/.git/hooks", "commit-msg").text = """
+    #!/bin/bash
+    echo "Running Conventional Commit check"
+    commit_message="\$1"
+    ./scripts/conventional-pre-commit.sh "\$commit_message"
+"""
+    "chmod +x .git/hooks/commit-msg".execute()
+}

scripts/conventional-pre-commit.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+# 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$"
+
+# Check if commit is conventional commit
+if grep -Eq "$pattern" "$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

scripts/pre-commit.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 echo "Running detekt check"
-./gradlew detekt
+./gradlew detekt