XState

XState models list updates as actor events. The official @xstate/react useSelector() hook renders the actor snapshot, while Likftc handles transition-safe keys.

Live before-and-after

Executed source

Imported verbatim with ?raw from every implementation file shown below. Playback timing and FLIP controls come from the shared demo harness.

main.tsxreact-state-panels.tsx

src/xstate/main.tsxTSX · 43 linesCopy

/** @jsxImportSource react */

import { useLikftc } from "@vp-tw/likftc/react";
import { useSelector } from "@xstate/react";
import { StrictMode } from "react";
import { flushSync } from "react-dom";
import { createRoot } from "react-dom/client";
import { createActor, fromTransition, type ActorRefFrom } from "xstate";

import { mountFrameworkDemo, type DemoFrameState, type DemoRuntime } from "../shared/demo.js";
import { ReactStatePanels } from "../shared/react-state-panels.js";

type FrameEvent = { readonly frame: DemoFrameState; readonly type: "frame.changed" };

function Runtime({ actor }: { readonly actor: ActorRefFrom<ReturnType<typeof createFrameLogic>> }) {
  const frame = useSelector(actor, (snapshot) => snapshot.context);
  const entries = useLikftc(frame.items, { getId: (item) => item.id });
  return <ReactStatePanels entries={entries} frame={frame} label="XSTATE" />;
}

function createFrameLogic(initialState: DemoFrameState) {
  return fromTransition((_state: DemoFrameState, event: FrameEvent) => event.frame, initialState);
}

await mountFrameworkDemo("XState + React", (target, initialState): DemoRuntime => {
  const actor = createActor(createFrameLogic(initialState));
  actor.start();
  const root = createRoot(target);
  flushSync(() =>
    root.render(
      <StrictMode>
        <Runtime actor={actor} />
      </StrictMode>,
    ),
  );
  return {
    destroy: () => {
      flushSync(() => root.unmount());
      actor.stop();
    },
    update: (frame) => flushSync(() => actor.send({ frame, type: "frame.changed" })),
  };
});

src/shared/react-state-panels.tsxTSX · 68 linesCopy

/** @jsxImportSource react */

import {
  createAfterRows,
  createBeforeRows,
  describeRow,
  type DemoFrameState,
  type DemoItem,
  type DemoRenderedRow,
} from "./demo.js";

function Row({ row }: { readonly row: DemoRenderedRow }) {
  return (
    <li
      className="runtime-row"
      data-collision={String(row.kind === "collision")}
      data-id={row.item.id}
      data-key={row.keyText}
      data-kind={row.kind}
      data-phase={row.kind === "exiting" ? "exiting" : "current"}
      data-slot={String(row.slot)}
    >
      <b>{row.item.id.toUpperCase()}</b>
      <span>{row.item.label}</span>
      <code>{row.keyText}</code>
      <em>{describeRow(row.kind)}</em>
    </li>
  );
}

function Panel({
  corrected,
  label,
  rows,
}: {
  readonly corrected: boolean;
  readonly label: string;
  readonly rows: readonly DemoRenderedRow[];
}) {
  return (
    <article className="runtime-panel">
      <small>{corrected ? `WITH LIKFTC + ${label}` : `WITHOUT + ${label}`}</small>
      <h3>{corrected ? "Presence identity" : "Logical ID key"}</h3>
      <ol data-list={corrected ? "after" : "before"}>
        {rows.map((row) => (
          <Row key={row.key} row={row} />
        ))}
      </ol>
    </article>
  );
}

export function ReactStatePanels({
  entries,
  frame,
  label,
}: {
  readonly entries: readonly { readonly item: DemoItem; readonly key: number }[];
  readonly frame: DemoFrameState;
  readonly label: string;
}) {
  return (
    <div className="runtime-grid">
      <Panel corrected={false} label={label} rows={createBeforeRows(frame)} />
      <Panel corrected label={label} rows={createAfterRows(frame, entries)} />
    </div>
  );
}

This uses full XState v5 actor semantics rather than @xstate/store, so the example can grow into guards, event routing, or actor composition without changing its React integration.