Add fix for $.fn.data calls

src/jquery/data.js

@@ -1,7 +1,8 @@
 import { migrateWarn } from "../main.js";
 import { camelCase } from "../utils.js";
 
-var oldData = jQuery.data;
+var oldData = jQuery.data,
+ oldFnData = jQuery.fn.data;
 
 jQuery.data = function( elem, name, value ) {
 	var curData, sameKeys, key;
@@ -38,3 +39,42 @@ jQuery.data = function( elem, name, value ) {
 
 	return oldData.apply( this, arguments );
 };
+
+jQuery.fn.extend( {
+    data: function( key, value ) {
+        var args, result;
+        if ( arguments.length === 0 && typeof Proxy !== "undefined" ) {
+            result = oldFnData.call( this );
+	    if(!result) {
+ 	      return result;
+	    }
+            // eslint-disable-next-line no-undef
+            return new Proxy( result, {
+                get: function( target, prop ) {
+                    if (
+                        prop !== camelCase( prop ) &&
+                        target[ prop ] === undefined
+                    ) {
+                        migrateWarn(
+                            "jQuery.fn.data() always sets/gets camelCased names: " +
+                                prop
+                        );
+                        return target[ camelCase( prop ) ];
+                    }
+                    return target[ prop ];
+                }
+            } );
+        }
+        if ( arguments.length > 0 && typeof key === "string" && key !== camelCase( key ) ) {
+            migrateWarn(
+                "jQuery.fn.data() always sets/gets camelCased names: " + key
+            );
+            args =
+                arguments.length > 1 ?
+                    [ camelCase( key ), value ] :
+                    [ camelCase( key ) ];
+            return oldFnData.apply( this, args );
+        }
+        return oldFnData.apply( this, arguments );
+    }
+} );