[index.js] convert keyboard numeric keystroke values

Detail Notes :

1. if the KeyboardEvent doesn't have a 'key' option,
2. in the keyDown event,
3. in the keyboard input is in the range 0-9,
4. returns the number corresponding to event.key

com.twin.app.shoptime/src/index.js

@@ -42,6 +42,25 @@ if (typeof window === "object") {
     document.addEventListener("keyup", getFalseOnRepeat, true);
   }
 
+  // Adding the 'key' option to KeyboardEvent in webOS3.0
+  if (!("key" in window.KeyboardEvent.prototype)) {
+    const getKeyOption = (event) => {
+      console.log(
+        "KeyDown Event / This browser does not have a 'key' value for KeyboardEvent"
+      );
+
+      if (event.keyCode >= 48 && event.keyCode <= 57) {
+        Object.defineProperty(event, "key", {
+          get: function () {
+            return this.keyCode - 48;
+          },
+        });
+      }
+    };
+
+    document.addEventListener("keydown", getKeyOption, true);
+  }
+
   window.store = store;
 
   render(appElement, document.getElementById("root"));