chore(deps): update dependency @types/estree to v0.0.48 (#966)

Author: JustinBeckwith

package.json

@@ -62,7 +62,7 @@
     "@compodoc/compodoc": "1.1.11",
     "@types/acorn": "^4.0.2",
     "@types/console-log-level": "^1.4.0",
-    "@types/estree": "0.0.45",
+    "@types/estree": "0.0.48",
     "@types/extend": "^3.0.0",
     "@types/mocha": "^8.0.0",
     "@types/mv": "^2.1.0",

src/agent/util/validator.ts

@@ -23,7 +23,7 @@ import * as estree from 'estree';
  * @param {Object} node AST Node (as per the Mozilla Parser API)
  * @return {boolean} if the exper
  */
-export function isValid(node: estree.Node): boolean {
+export function isValid(node: estree.Node | null): boolean {
   // Empty expression is allowed
   if (node === null) {
     return true;