Perf: append large array

Build/lib/append-array-in-place.ts

@@ -0,0 +1,21 @@
+const MAX_BLOCK_SIZE = 65535; // max parameter array size for use in Webkit
+
+export function appendArrayInPlace<T>(dest: T[], source: T[]) {
+  let offset = 0;
+  let itemsLeft = source.length;
+
+  if (itemsLeft <= MAX_BLOCK_SIZE) {
+    // eslint-disable-next-line prefer-spread -- performance
+    dest.push.apply(dest, source);
+  } else {
+    while (itemsLeft > 0) {
+      const pushCount = Math.min(MAX_BLOCK_SIZE, itemsLeft);
+      const subSource = source.slice(offset, offset + pushCount);
+      // eslint-disable-next-line prefer-spread -- performance
+      dest.push.apply(dest, subSource);
+      itemsLeft -= pushCount;
+      offset += pushCount;
+    }
+  }
+  return dest;
+}