optimize: short-circuit update (//)

2026-02-19 21:54:49 +08:00
parent 4380fa85c4
commit b57fea3104
1 changed files with 6 additions and 0 deletions
--- a/nix-js/runtime-ts/src/operators.ts
+++ b/nix-js/runtime-ts/src/operators.ts
@@ -270,6 +270,12 @@ export const op = {
  update: (a: NixValue, b: NixValue): NixAttrs => {
    const mapA = forceAttrs(a);
    const mapB = forceAttrs(b);
+    if (mapA.size === 0) {
+      return mapB;
+    }
+    if (mapB.size === 0) {
+      return mapA;
+    }
    const result: NixAttrs = new Map(mapA);
    for (const [k, v] of mapB) {
      result.set(k, v);