perf: v-for fragments do not need to track dynamicChildren

2019-10-20 23:43:56 -04:00
parent 71f3826f99
commit 1b9bd6912e
4 changed files with 19 additions and 18 deletions
--- a/packages/compiler-core/src/transforms/vFor.ts
+++ b/packages/compiler-core/src/transforms/vFor.ts
@@ -71,7 +71,8 @@ export const transformFor = createStructuralDirectiveTransform(
      ? PatchFlags.KEYED_FRAGMENT
      : PatchFlags.UNKEYED_FRAGMENT
    const codegenNode = createSequenceExpression([
-      createCallExpression(helper(OPEN_BLOCK)),
+      // fragment blocks disable tracking since they always diff their children
+      createCallExpression(helper(OPEN_BLOCK), [`false`]),
      createCallExpression(helper(CREATE_BLOCK), [
        helper(FRAGMENT),
        `null`,