test: Add --gitlab flag

test/main.sh

@@ -7,11 +7,21 @@ GREEN="\e[32m"
 YELLOW="\e[33m"
 RESET="\e[0m"
 
-if [[ "$1" =~ --all|-a ]]; then
-	check_all=true
-else
-	check_all=false
-fi
+DIFF_COMMAND="diff --color"
+
+for arg in "$@"; do
+	case "$arg" in
+		--all|-a)
+			check_all=true
+			;;
+		--gitlab|-g)
+			# Disable colored output, because alpine diff is missing --color flag
+			DIFF_COMMAND="diff"
+			;;
+	esac
+done
+
+
 
 EXIT_STATUS=0
 
@@ -74,7 +84,7 @@ _test_dir() {
 		input_file=${input//*\/}
 		test_case_number=${input_file%%_in.txt}
 
-		if ! diff --color <(./a.out < "test_data/${test_case_number}_in.txt")  "test_data/${test_case_number}_out.txt"; then
+		if ! $DIFF_COMMAND <(./a.out < "test_data/${test_case_number}_in.txt")  "test_data/${test_case_number}_out.txt"; then
 			EXIT_STATUS=1
 			((failed_inputs++))
 			_log 2 "$dir (#$test_case_number)"