update elements and fix some bugs

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

Index: lib/src/prism/tests/languages/scss/statement_feature.test
diff --git a/lib/src/prism/tests/languages/scss/statement_feature.test b/lib/src/prism/tests/languages/scss/statement_feature.test
new file mode 100644
index 0000000000000000000000000000000000000000..7a85f9c77a28e80b11cfa68d189d33633ef3e004
--- /dev/null
+++ b/lib/src/prism/tests/languages/scss/statement_feature.test
@@ -0,0 +1,21 @@
+$foo: "bar" !default;
+@extend .baz !optional;
+
+----------------------------------------------------
+
+[
+	["variable", "$foo"],
+	["punctuation", ":"],
+	["string", "\"bar\""],
+	["statement", "!default"],
+	["punctuation", ";"],
+
+	["keyword", "@extend"],
+	" .baz ",
+	["statement", "!optional"],
+	["punctuation", ";"]
+]
+
+----------------------------------------------------
+
+Checks for statements.