refactoring for testing parser

spec/parser.spec.js

@@ -0,0 +1,10 @@
+const parser = require('../src/services/search/parser');
+
+describe("Parser", () => {
+    it("fulltext parser without content", () => {
+        const exps = parser(["hello", "hi"], [], false);
+
+        expect(exps.constructor.name).toEqual("NoteCacheFulltextExp");
+        expect(exps.tokens).toEqual(["hello", "hi"]);
+    });
+});