Cover gmail-gmail plain cases

__tests__/html-gmail-gmail.test.ts

@@ -13,5 +13,5 @@ describe("[HTML] GMail-GMail", () => {
     EMAIL_VENDORS.GMAIL
   );
 
-  describe("One", describeFunction("one", ["0ssss"]));
+  describe("One", describeFunction("one", [""]));
 });

__tests__/plain-gmail-gmail.test.ts

+const path = require("path");
+import { describe } from "@jest/globals";
+import { createDescribePlainTestCases } from "./utils";
+
+const TESTS_GLOBAL_PATH = "/files/gmail-gmail";
+const testsPath = path.resolve(__dirname, `.${TESTS_GLOBAL_PATH}`);
+
+describe("[Plain] GMail-GMail", () => {
+  const describeFunction = createDescribePlainTestCases(testsPath);
+
+  describe("One", describeFunction("one", ["04", "17", "18", "20"]));
+});