perf: replace Object assign with direct mutation in feature code (#5048)

Object.assign is very performance Heavy, when compared with direct assignment, and can easily be replaced with direct mutations in the creational functions. Since theese get called *a lot* when the data changes, especially with large amounts of data, the performance impact is quite huge.

Co-authored-by: Günter Manz <[email protected]>

packages/table-core/src/core/cell.ts

@@ -52,14 +52,11 @@ export function createCell<TData extends RowData, TValue>(
  }
 
  table._features.forEach(feature => {
- Object.assign(
- cell,
- feature.createCell?.(
- cell as Cell<TData, TValue>,
- column,
- row as Row<TData>,
- table
- )
+ feature.createCell?.(
+ cell as Cell<TData, TValue>,
+ column,
+ row as Row<TData>,
+ table
  )
  }, {})
 

packages/table-core/src/core/column.ts

@@ -119,9 +119,9 @@ export function createColumn<TData extends RowData, TValue>(
  ),
  }
 
- column = table._features.reduce((obj, feature) => {
- return Object.assign(obj, feature.createColumn?.(column, table))
- }, column)
+ for (const feature of table._features) {
+ feature.createColumn?.(column, table)
+ }
 
  // Yes, we have to convert table to uknown, because we know more than the compiler here.
  return column as Column<TData, TValue>