add failing tests

I noticed that some of the tests were failing, and while looking at
them, it happened because the tests were structured like this:

```html
    <div
      class="
        backdrop-filter
        backdrop-filter-none
        backdrop-blur-lg
        backdrop-brightness-50
        backdrop-contrast-0
        backdrop-grayscale
        backdrop-hue-rotate-90
        backdrop-invert
        backdrop-opacity-75
        backdrop-saturate-150
        backdrop-sepia
      "
    ></div>
```

This means that the class names themselves eventually end up like this: `backdrop-filter-none\n`
-> (Notice the `\n`)

/cc @thecrypticace

oxide/crates/core/src/parser.rs

@@ -564,6 +564,49 @@ mod test {
         assert_eq!(candidates, vec!["content-['hello_[_]_world']"]);
     }
 
+    #[test]
+    fn it_should_ignore_leading_spaces() {
+        let candidates = run("        backdrop-filter-none", false);
+        assert_eq!(candidates, vec!["backdrop-filter-none"]);
+    }
+
+    #[test]
+    fn it_should_ignore_trailing_spaces() {
+        let candidates = run("backdrop-filter-none        ", false);
+        assert_eq!(candidates, vec!["backdrop-filter-none"]);
+    }
+
+    #[test]
+    fn it_should_keep_classes_before_an_ending_newline() {
+        let candidates = run("backdrop-filter-none\n", false);
+        assert_eq!(candidates, vec!["backdrop-filter-none"]);
+    }
+
+    #[test]
+    fn it_should_parse_out_the_correct_classes_from_tailwind_tests() {
+        // From: tests/arbitrary-variants.test.js
+        let candidates = run(
+            r#"
+                <div class="dark:lg:hover:[&>*]:underline"></div>
+
+                <div class="[&_.foo\_\_bar]:hover:underline"></div>
+                <div class="hover:[&_.foo\_\_bar]:underline"></div>
+            "#,
+            false,
+        );
+        // TODO: it should not include additional (separate) classes: class, hover:, foo: bar, underline
+        // TODO: Double check the expectations based on above information
+        assert_eq!(
+            candidates,
+            vec![
+                "class",
+                r#"dark:lg:hover:[&>*]:underline"#,
+                r#"[&_.foo\_\_bar]:hover:underline"#,
+                r#"hover:[&_.foo\_\_bar]:underline"#
+            ]
+        );
+    }
+
     #[test]
     fn potential_candidates_are_skipped_when_hitting_impossible_characters() {
         let candidates = run("        <p class=\"text-sm text-blue-700\">A new software update is available. See what’s new in version 2.0.4.</p>", false);