add more test cases

README.md

@@ -1,6 +1,6 @@
 # ESLint Plugin: eslint-plugin-no-explicit-undefined
 
-Disallow the use of `undefined` as an explicit type in TypeScript and instead use optional chaining (`?:`) instead.
+Disallow the use of `undefined` as an explicit type in TypeScript and instead use optional operator (`?`) instead.
 
 ## 📚 Rule Examples
 

package.json

@@ -1,7 +1,7 @@
 {
   "name": "eslint-plugin-no-explicit-undefined",
-  "version": "0.0.7",
-  "description": "Eslint rule to prevent undefined declaration in favor of optional chaining (?:) operator in Typescript",
+  "version": "1.0.0",
+  "description": "Eslint rule to prevent undefined declaration in favor of optional parameter (?) operator in Typescript",
   "main": "index.js",
   "scripts": {
     "test": "jest"

tests/no-undefined-type-declaration.test.js

@@ -30,5 +30,9 @@ ruleTester.run('no-undefined-type', rule, {
       code: "interface Example { prop: string | undefined; }",
       errors: [{ message }],
     },
+    {
+      code: "const example = (param?: string | undefined) => {}",
+      errors: [{ message }]
+    }
   ],
 });