Revert "refactor(treeChanges): Simplify variables when calculating tree changes"

This reverts commit f65cfb3
Also adds retainedWithToParams

Author: christopherthielen

src/path/pathUtils.ts

@@ -125,13 +125,16 @@ export class PathUtils {
 
     let from: PathNode[], retained: PathNode[], exiting: PathNode[], entering: PathNode[], to: PathNode[];
 
-    from     = fromPath;
-    retained = from.slice(0, keep).map(applyToParams); // applyToParams to update dynamic params
-    exiting  = from.slice(keep);
-    entering = toPath.slice(keep);
-    to       = (retained).concat(entering);
+    from                  = fromPath;
+    retained              = from.slice(0, keep);
+    exiting               = from.slice(keep);
 
-    return { from, to, retained, exiting, entering };
+    // Create a new retained path (with shallow copies of nodes) which have the params of the toPath mapped
+    const retainedWithToParams  = retained.map(applyToParams);
+    entering              = toPath.slice(keep);
+    to                    = (retainedWithToParams).concat(entering);
+
+    return { from, to, retained, retainedWithToParams, exiting, entering };
   }
 
   /**