Add enforce insert issue number unit tests

tests/enforce-insert-issue-number-test.bats

@@ -0,0 +1,47 @@
+#!/usr/bin/env bats
+
+LOG="./tests/tests.log"
+TEST_BRANCH="issue-9999999999/add-this-and-that"
+
+logTest() {
+    # $1 indicates the test status [PASS, FAIL]
+    date >> "$LOG"
+    echo "enforce insert issue number test: $1" >> "$LOG"
+    echo "" >> "$LOG"
+    echo "--------------------------------------------" >> "$LOG"
+    echo "" >> "$LOG"
+}
+
+setup() {
+    # Create a test branch that will be used to verify that the `commit-msg` hook works
+    # 'issue-9999999999' is highly unlikely to exists and thus safer than having a normal issue number
+    # which might collide with a real branch.
+    git checkout -b "$TEST_BRANCH"
+}
+
+teardown() {
+    # Go back to the previous branch
+    git checkout -
+    # Remove test branch
+    git branch -D "$TEST_BRANCH"
+}
+
+@test "correct issue number format" {
+    run $(git commit --allow-empty -m "$TEST_BRANCH")
+    if [ "$status" -eq 0 ]; then
+	logTest "PASS"
+    else
+	logTest "FAIL"
+	[ "$output" = "incorrect commit message specified" ]
+    fi
+}
+
+@test "wrong issue number format" {
+    run git commit --allow-empty -m "NOT-CORRECT-ISSUE-FORMAT"
+    if [ "$status" -eq 1 ]; then
+	logTest "PASS"
+    else
+	logTest "FAIL"
+	[ "$output" = "incorrect commit message specified" ]
+    fi
+}