update elements and fix some bugs

lib/src/prism/tests/languages/dart/operator_feature.test

Index: lib/src/prism/tests/languages/dart/operator_feature.test
diff --git a/lib/src/prism/tests/languages/dart/operator_feature.test b/lib/src/prism/tests/languages/dart/operator_feature.test
new file mode 100644
index 0000000000000000000000000000000000000000..5d631fd0bb5415638a09ad4474448851406a7bc3
--- /dev/null
+++ b/lib/src/prism/tests/languages/dart/operator_feature.test
@@ -0,0 +1,33 @@
+++ --
+* / % ~/
++ - ! ~
+<< >> ?
+& ^ |
+>= > <= <
+as is is!
+== != && ||
+= *= /= ~/=
+%= += -=
+<<= >>=
+&= ^= |=
+
+----------------------------------------------------
+
+[
+	["operator", "++"], ["operator", "--"],
+	["operator", "*"], ["operator", "/"], ["operator", "%"], ["operator", "~/"],
+	["operator", "+"], ["operator", "-"], ["operator", "!"], ["operator", "~"],
+	["operator", "<<"], ["operator", ">>"], ["operator", "?"],
+	["operator", "&"], ["operator", "^"], ["operator", "|"],
+	["operator", ">="], ["operator", ">"], ["operator", "<="], ["operator", "<"],
+	["operator", "as"], ["operator", "is"], ["operator", "is!"],
+	["operator", "=="], ["operator", "!="], ["operator", "&&"], ["operator", "||"],
+	["operator", "="], ["operator", "*="], ["operator", "/="], ["operator", "~/="],
+	["operator", "%="], ["operator", "+="], ["operator", "-="],
+	["operator", "<<="], ["operator", ">>="],
+	["operator", "&="], ["operator", "^="], ["operator", "|="]
+]
+
+----------------------------------------------------
+
+Checks for all operators.