Repository navigation
[2.0 / next] A first-load <Loading> reveals with isPending() === true when the memo only holds an answer to an older question (F-9) #4569
Description
Describe the bug
a2 awaits a0, and a0 depends on a signal s. On the first load under <Loading>, a0:0 lands and a2 asks a2:11. Then s changes, so a0 asks a0:1. When a2:11 lands, a2 holds an answer to the old question while the current one is still in flight. At that point the boundary reveals its content with isPending(() => a2()) reading true, and keeps showing pending until a2:20 lands.
a2 has never committed, so per F-9 it has no verdict: "a first load is loading, not pending", and isPending "cannot be true on creation". Inside an owner, isPending of such a node should do what the read does and hold the boundary until the answer to the current question lands.
Found by diffing generated programs from ryansolid/reactivescript against Solid.
Your Example Website or App
The vitest spec below (in packages/web/test/), on next @ 62745f6.
Steps to Reproduce the Bug or Issue
import { render } from "@solidjs/web";
import { createMemo, createSignal, flush, isPending, Loading } from "solid-js";
import { expect, it } from "vitest";
const tick = async () => { for (let i = 0; i < 2; i++) { await new Promise(r => setTimeout(r, 0)); flush(); } };
it("a first load does not reveal with isPending() === true", async () => {
const flights = new Map<string, (v: number) => void>();
const ask = (key: string) => new Promise<number>(resolve => flights.set(key, resolve));
const [s, setS] = createSignal(0);
const el = document.createElement("div");
const frames: string[] = [];
const dispose = render(() => {
const a0 = createMemo(() => ask("a0:" + s()));
const a2 = createMemo(async () => ask("a2:" + (await a0())));
return (
<Loading fallback={<p>loading</p>}>
<b>{isPending(() => a2()) ? "pending" : "settled"}</b>
</Loading>
);
}, el);
await tick(); frames.push(el.textContent!);
flights.get("a0:0")!(11); await tick(); frames.push(el.textContent!); // asks a2:11
setS(1); flush(); await tick(); frames.push(el.textContent!); // asks a0:1
flights.get("a2:11")!(16); await tick(); frames.push(el.textContent!); // an answer to the old question
flights.get("a0:1")!(20); await tick(); frames.push(el.textContent!); // asks a2:20
flights.get("a2:20")!(21); await tick(); frames.push(el.textContent!);
dispose();
expect(frames).toEqual(["loading", "loading", "loading", "loading", "loading", "settled"]);
});npx vitest run in packages/web. Received frames: loading, loading, loading, pending, pending, settled.
Expected behavior
Frames loading, loading, loading, loading, loading, settled: the boundary first reveals when a2 answers the current question, and its first frame shows no pending verdict.
Platform
- OS: macOS
- Browser: n/a (jsdom)
- Version: solid-js 2.0.0-rc.20,
next@ 62745f6
Activity
ryansolid commentedon Nov 1, 2026
test(signals): pin #4569 — a first load answered while pending by pro…
ryansolid commentedon Nov 1, 2026
Ruled and pinned on
nextby #4571 (77931d6): a first load answered while pending by propagation is committed and pending (D-23).Generated by Claude Code