{src,test}/assert_regex: Make case-sensitivity transparent

src/assert_regex.bash

@@ -41,9 +41,15 @@ assert_regex() {
 		| batslib_decorate 'ERROR: assert_regex' \
 		| fail
 	elif ! [[ "${value}" =~ ${pattern} ]]; then
+		if shopt -p nocasematch &>/dev/null; then
+			local case_sensitive=insensitive
+		else
+			local case_sensitive=sensitive
+		fi
 		batslib_print_kv_single_or_multi 8 \
 			'value' "${value}" \
 			'pattern'  "${pattern}" \
+			'case' "${case_sensitive}" \
 		| batslib_decorate 'value does not match regular expression' \
 		| fail
 	fi

test/assert_regex.bats

@@ -19,6 +19,7 @@ load test_helper
 -- value does not match regular expression --
 value    : bcd
 pattern  : ^[a-z]b[c-z]+
+case     : sensitive
 --
 ERR_MSG
 }
@@ -47,6 +48,23 @@ value (2 lines):
   123
 pattern (1 lines):
   ^[a-z]b[c-z]+
+case (1 lines):
+  sensitive
+--
+ERR_MSG
+
+  shopt -s nocasematch
+  run assert_regex $'bcd\n123' '^[a-z]b[c-z]+'
+  assert_test_fail <<'ERR_MSG'
+
+-- value does not match regular expression --
+value (2 lines):
+  bcd
+  123
+pattern (1 lines):
+  ^[a-z]b[c-z]+
+case (1 lines):
+  insensitive
 --
 ERR_MSG
 }