@sometic/history

Undo and redo for Sometic: execute reversible entries, walk an undo stack, redo cleared branches, and checkpoint named markers.

createHistoryController is store-agnostic. You supply execute and undo (plus optional redo). Depth is capped, concurrent operations are serialized, and a new execute clears the redo branch the way desktop editors do.

Why it exists: reversible edits show up in canvases, document editors, and settings screens. Without a shared stack, each UI reinvents race handling and depth limits. This package owns that timeline so adapters only bind buttons.

Depends on @sometic/core only.

Docs: introduction and https://sometic.dev.

Install

pnpm add @sometic/history

npm install @sometic/history

yarn add @sometic/history

Usage

import { createHistoryController } from "@sometic/history";

const history = createHistoryController({ maxDepth: 50 });
let title = "Untitled";

await history.execute({
    label: "Rename",
    execute: () => {
        const previous = title;
        title = "Invoice";
        return previous;
    },
    undo: (previous) => {
        title = previous;
    },
});

await history.undo();
await history.redo();
history.checkpoint("before-export");
history.clear();
history.dispose();

Subscribe for toolbar state:

const stop = history.subscribe((state) => {
    setUndoEnabled(state.canUndo);
    setRedoEnabled(state.canRedo);
});

stop();

API

• createHistoryController({ maxDepth?, onChange? }).
• execute(entry), undo(), redo(), canUndo(), canRedo().
• checkpoint(label?), clear(), getState().
• subscribe(listener), dispose(), disposed.

Empty undo/redo stacks and calls after dispose() throw typed errors (HISTORY_*). If redo is omitted, redo re-runs execute.

When not to use

Skip it for append-only audit logs; use @sometic/activity instead. Prefer operational transforms or CRDTs when multiple users edit the same document concurrently. This package is a local undo stack, not a sync protocol.

Docs

• Introduction
• https://sometic.dev

License

MIT