refactor: 改用 TypeScript。close #1.

lib/utils/htmlEscaper.ts

@@ -0,0 +1,22 @@
+const { replace } = ''
+
+// escape
+const ca = /[&<>'"]/g
+
+const esca = {
+  '&': '&amp;',
+  '<': '&lt;',
+  '>': '&gt;',
+  "'": '&#39;',
+  '"': '&quot;',
+}
+const pe = (m: keyof typeof esca) => esca[m]
+
+/**
+ * Safely escape HTML entities such as `&`, `<`, `>`, `"`, and `'`.
+ * @param {string} es the input to safely escape
+ * @returns {string} the escaped input, and it **throws** an error if
+ *  the input type is unexpected, except for boolean and numbers,
+ *  converted as string.
+ */
+export const escape = (es: string): string => replace.call(es, ca, pe)