prettybat: Allow reading from pipe (#51)

src/prettybat.sh

@@ -181,8 +181,10 @@ process_file() {
 	local formatter
 	
 	# Check that the file exists, and is a file.
-	check_exists  "$file" || return 1
-	check_is_file "$file" || return 1
+	if [[ "$file" != "-" ]]; then
+		check_exists  "$file" || return 1
+		check_is_file "$file" || return 1
+	fi
 
 	# Determine the formatter.
 	if [[ -n "$OPT_LANGUAGE" ]]; then
@@ -190,7 +192,9 @@ process_file() {
 		fext="$(map_language_to_extension "$lang")"
 	fi
 
-	formatter="$(map_extension_to_formatter "$fext")"
+	if [[ "$ext" != "-" ]]; then
+		formatter="$(map_extension_to_formatter "$fext")"
+	fi
 
 	# Debug: Print the name and formatter.
 	if "$DEBUG_PRINT_FORMATTER"; then
@@ -272,6 +276,9 @@ while shiftopt; do
 	# Debug options
 	--debug:formatter) DEBUG_PRINT_FORMATTER=true ;;
 
+	# Read from stdin
+	-) FILES+=("-") ;;
+
 	# bat options
 	-*) {
 		BAT_ARGS+=("$OPT=$OPT_VAL")

test/suite/prettybat.sh

@@ -10,3 +10,16 @@ test:version() {
 	prettybat --version | awk 'FNR <= 1 { print $1 }'
 	prettybat --version | awk 'p{print} /^$/ { p=1 }'
 }
+
+test:read_from_pipe() {
+	description "Test 'prettybat -'"
+
+	assert_equal "ABC" "$(echo "ABC" | prettybat)" 
+	assert_equal "ABC" "$(echo "ABC" | prettybat -)" 
+}
+
+test:read_from_pipe_with_formatter() {
+	description "Test 'prettybat - -lsh'"
+
+	assert_equal "-: shfmt" "$(echo "" | prettybat - -lsh --debug:formatter)" 
+}