update elements and fix some bugs

lib/src/prism/tests/languages/twig/string_feature.test

Index: lib/src/prism/tests/languages/twig/string_feature.test
diff --git a/lib/src/prism/tests/languages/twig/string_feature.test b/lib/src/prism/tests/languages/twig/string_feature.test
new file mode 100644
index 0000000000000000000000000000000000000000..ab108d02e018c2ce4660703142a60f876bc96150
--- /dev/null
+++ b/lib/src/prism/tests/languages/twig/string_feature.test
@@ -0,0 +1,33 @@
+{{ '' }}
+{{ "" }}
+{{ "ba\"r" }}
+{{ 'ba\'z' }}
+
+----------------------------------------------------
+
+[
+	["tag", [
+		["ld", [["punctuation", "{{"]]],
+		["string", [["punctuation", "'"], ["punctuation", "'"]]],
+		["rd", [["punctuation", "}}"]]]
+	]],
+	["tag", [
+		["ld", [["punctuation", "{{"]]],
+		["string", [["punctuation", "\""], ["punctuation", "\""]]],
+		["rd", [["punctuation", "}}"]]]
+	]],
+	["tag", [
+		["ld", [["punctuation", "{{"]]],
+		["string", [["punctuation", "\""], "ba\\\"r", ["punctuation", "\""]]],
+		["rd", [["punctuation", "}}"]]]
+	]],
+	["tag", [
+		["ld", [["punctuation", "{{"]]],
+		["string", [["punctuation", "'"], "ba\\'z", ["punctuation", "'"]]],
+		["rd", [["punctuation", "}}"]]]
+	]]
+]
+
+----------------------------------------------------
+
+Checks for strings.