refactoring and implementing clippy suggestions

src/syntax/check/test.rs

@@ -0,0 +1,28 @@
+use crate::syntax::{
+    check::{check_missing_filters, check_missing_sink, check_missing_streamer},
+    parse_syntax,
+};
+
+#[test]
+fn test_check_missing_streamer() {
+    let test_data = "| invert | save \"./image_processed.jpg\"";
+    let syntax = parse_syntax(test_data).unwrap();
+
+    assert_eq!(check_missing_streamer(&syntax), Err(0..1))
+}
+
+#[test]
+fn test_check_missing_filters() {
+    let test_data = "meow | | test | awa |   | nya";
+    let syntax = parse_syntax(test_data).unwrap();
+
+    assert_eq!(check_missing_filters(&syntax), Err(vec![5..8, 20..25]))
+}
+
+#[test]
+fn test_check_missing_sink() {
+    let test_data = "meow | invert | ";
+    let syntax = parse_syntax(test_data).unwrap();
+
+    assert_eq!(check_missing_sink(&syntax), Err(14..15))
+}