src: Add `assert_regex.bash`

Add a convenient version of `[[ =~ ]]`.

1 files changed, 16 insertions, 0 deletions

diff --git a/src/assert_regex.bash b/src/assert_regex.bash
new file mode 100644
index 0000000..b371bf3
--- /dev/null
+++ b/src/assert_regex.bash
@@ -0,0 +1,16 @@
+assert_regex() {
+	local -r value="${1}"
+	local -r pattern="${2}"
+
+	if [[ '' =~ ${pattern} ]] || (( ${?} == 2 )); then
+		echo "Invalid extended regular expression: \`${pattern}'" \
+		| batslib_decorate 'ERROR: assert_regex' \
+		| fail
+	elif ! [[ "${value}" =~ ${pattern} ]]; then
+		batslib_print_kv_single_or_multi 8 \
+			'value' "${value}" \
+			'pattern'  "${pattern}" \
+		| batslib_decorate 'value does not match regular expression' \
+		| fail
+	fi
+}