update elements and fix some bugs

lib/src/prism/tests/languages/scss/selector_feature.test

Index: lib/src/prism/tests/languages/scss/selector_feature.test
diff --git a/lib/src/prism/tests/languages/scss/selector_feature.test b/lib/src/prism/tests/languages/scss/selector_feature.test
new file mode 100644
index 0000000000000000000000000000000000000000..3749f2262b17f3b87f9cfc4e90f34238f723f4a9
--- /dev/null
+++ b/lib/src/prism/tests/languages/scss/selector_feature.test
@@ -0,0 +1,23 @@
+a {}
+p, div {}
+#foobar .foo {}
+&:hover {}
+&-sidebar {}
+#context a%extreme {}
+#{$selector}:before {}
+
+----------------------------------------------------
+
+[
+	["selector", ["a "]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["p, div "]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["#foobar .foo "]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["&:hover "]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["&-sidebar "]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["#context a", ["placeholder", "%extreme"]]], ["punctuation", "{"], ["punctuation", "}"],
+	["selector", ["#{$selector}:before "]], ["punctuation", "{"], ["punctuation", "}"]
+]
+
+----------------------------------------------------
+
+Checks for selectors.