fix(core): restore undo of autoformat conversions

packages/core/src/api/blockManipulation/commands/updateBlock/updateBlock.test.ts

@@ -1,13 +1,45 @@
+import { closeHistory } from "@tiptap/pm/history";
+import { ReplaceStep, Transform } from "prosemirror-transform";
 import { describe, expect, it } from "vite-plus/test";
 
-import type { PartialBlock } from "../../../../blocks/defaultBlocks.js";
+import type {
+  DefaultBlockSchema,
+  DefaultInlineContentSchema,
+  DefaultStyleSchema,
+  PartialBlock,
+} from "../../../../blocks/defaultBlocks.js";
 import { getBlockInfo } from "../../../getBlockInfoFromPos.js";
 import { getNodeById } from "../../../nodeUtil.js";
 import { setupTestEnv } from "../../setupTestEnv.js";
-import { updateBlock } from "./updateBlock.js";
+import { updateBlock, updateBlockTr } from "./updateBlock.js";
 
 const getEditor = setupTestEnv();
 
+describe("Test updateBlock undo/redo", () => {
+  it.each([
+    ["paragraph", "divider"],
+    ["heading", "divider"],
+    ["codeBlock", "image"],
+    ["divider", "paragraph"],
+    ["paragraph", "heading"],
+  ] as const)("can undo and redo %s → %s", (from, to) => {
+    const editor = getEditor();
+    editor.updateBlock("empty-paragraph", { type: from });
+    const before = editor.prosemirrorState.doc;
+    // Isolate the conversion from fixture preparation.
+    editor.prosemirrorView.dispatch(closeHistory(editor.prosemirrorState.tr));
+    editor.updateBlock("empty-paragraph", { type: to });
+    const after = editor.prosemirrorState.doc;
+    expect(editor.getBlock("empty-paragraph")?.type).toBe(to);
+    after.check();
+
+    expect(editor.undo()).toBe(true);
+    expect(editor.prosemirrorState.doc.eq(before)).toBe(true);
+    expect(editor.redo()).toBe(true);
+    expect(editor.prosemirrorState.doc.eq(after)).toBe(true);
+  });
+});
+
 describe("Test updateBlock typing", () => {
   it("Type is inferred correctly", () => {
     try {
@@ -626,6 +658,59 @@ describe("Test updateBlock", () => {
  * only a small part changed.
  */
 describe("Test updateBlock minimal steps", () => {
+  it.each([
+    ["paragraph", "divider"],
+    ["heading", "divider"],
+    ["codeBlock", "image"],
+  ] as const)(
+    "%s → %s replaces only the empty content node and can be inverted",
+    (from, to) => {
+      const editor = getEditor();
+      editor.updateBlock("paragraph-with-children", {
+        content: [],
+        props: { backgroundColor: "red" },
+      });
+      editor.updateBlock("paragraph-with-children", { type: from });
+      const before = editor.prosemirrorState.doc;
+      const original = getNodeById("paragraph-with-children", before)!;
+      const contentPos = original.posBeforeNode + 1;
+      const tr = new Transform(before);
+      updateBlockTr<
+        DefaultBlockSchema,
+        DefaultInlineContentSchema,
+        DefaultStyleSchema
+      >(tr, original.posBeforeNode, { type: to });
+
+      // Only the paragraph's two structural tokens become one leaf token.
+      // Its enclosing container and nonempty children must not be replaced.
+      expect(tr.steps).toHaveLength(1);
+      const step = tr.steps[0];
+      expect(step).toBeInstanceOf(ReplaceStep);
+      if (!(step instanceof ReplaceStep)) {
+        throw new Error("Expected a single content-node ReplaceStep");
+      }
+      expect(step.from).toBe(contentPos);
+      expect(step.to).toBe(contentPos + 2);
+      expect(step.slice.size).toBe(1);
+      expect(step.slice.content.firstChild?.type.name).toBe(to);
+      const updated = getNodeById("paragraph-with-children", tr.doc)!;
+      expect(updated.node.attrs).toEqual(original.node.attrs);
+      expect(updated.node.child(1)).toBe(original.node.child(1));
+      expect(getNodeById("paragraph-0", tr.doc)!.node).toBe(
+        getNodeById("paragraph-0", before)!.node,
+      );
+      expect(getNodeById("paragraph-9", tr.doc)!.node).toBe(
+        getNodeById("paragraph-9", before)!.node,
+      );
+      tr.doc.check();
+
+      const inverse = new Transform(tr.doc);
+      inverse.step(step.invert(before));
+      expect(inverse.doc.eq(before)).toBe(true);
+      inverse.doc.check();
+    },
+  );
+
   // Runs `updateBlock` in a throwaway transaction and returns the resulting
   // steps as JSON for inspection.
   const getSteps = (blockId: string, update: PartialBlock<any, any, any>) => {

packages/core/src/api/blockManipulation/commands/updateBlock/updateBlock.ts

@@ -435,7 +435,7 @@ function replaceContentMinimal(
  *   for each changed attribute. These are minimal steps that don't touch the
  *   node's content.
  * - If the type changes, `setNodeMarkup` is used, which keeps the node's content
- *   via a `ReplaceAroundStep`.
+ *   via a `ReplaceAroundStep`, except when converting a non-leaf into a leaf.
  */
 function setNodeMarkupMinimal(
   tr: Transform,
@@ -471,6 +471,30 @@ function setNodeMarkupMinimal(
     return;
   }
 
+  if (!node.isLeaf && newType.isLeaf) {
+    // setNodeMarkup preserves a non-leaf's content gap via a ReplaceAroundStep.
+    // After conversion to a leaf, that gap sits outside the node and the inverse
+    // step fails its structure check. A leaf accepts only empty content, so
+    // there is no gap to preserve: changing these two structural tokens into
+    // one leaf token is the smallest possible replacement. Leave the enclosing
+    // block container, its children, and adjacent blocks untouched. Use a strict
+    // step so invalid parent content is rejected instead of fitted/coerced.
+    tr.step(
+      new ReplaceStep(
+        pos,
+        pos + node.nodeSize,
+        new Slice(
+          Fragment.from(
+            newType.createChecked(mergedAttrs, node.content, node.marks),
+          ),
+          0,
+          0,
+        ),
+      ),
+    );
+    return;
+  }
+
   // Type changed - setNodeMarkup keeps the content via a ReplaceAroundStep.
   tr.setNodeMarkup(pos, newType, mergedAttrs);
 }

packages/core/src/yjs/comments/RESTYjsThreadStore.test.ts

@@ -40,46 +40,51 @@ describe("RESTYjsThreadStore", () => {
   it("sends resolvable yjs positions along with the thread", async () => {
     const { editor, doc, fragment } = createCollabEditor();
 
-    const requests: any[] = [];
-    vi.spyOn(globalThis, "fetch").mockImplementation((async (
-      _url: any,
-      init: any,
-    ) => {
-      requests.push(JSON.parse(init.body));
-      return new Response("{}", {
-        status: 200,
-        headers: { "Content-Type": "application/json" },
-      });
-    }) as any);
+    try {
+      const requests: any[] = [];
+      vi.spyOn(globalThis, "fetch").mockImplementation((async (
+        _url: any,
+        init: any,
+      ) => {
+        requests.push(JSON.parse(init.body));
+        return new Response("{}", {
+          status: 200,
+          headers: { "Content-Type": "application/json" },
+        });
+      }) as any);
 
-    const store = new RESTYjsThreadStore(
-      "https://example.com/threads",
-      {},
-      doc.getMap("threads"),
-      new DefaultThreadStoreAuth("user-1", "editor"),
-    );
+      const store = new RESTYjsThreadStore(
+        "https://example.com/threads",
+        {},
+        doc.getMap("threads"),
+        new DefaultThreadStoreAuth("user-1", "editor"),
+      );
 
-    await store.addThreadToDocument({
-      threadId: "thread-1",
-      selection: { anchor: 3, head: 8 },
-      editor,
-    });
+      await store.addThreadToDocument({
+        threadId: "thread-1",
+        selection: { anchor: 3, head: 8 },
+        editor,
+      });
 
-    expect(requests).toHaveLength(1);
-    const { yjs } = requests[0].selection;
-    expect(yjs).toBeDefined();
+      expect(requests).toHaveLength(1);
+      const { yjs } = requests[0].selection;
+      expect(yjs).toBeDefined();
 
-    // the relative positions must resolve back to the positions we passed in
-    const state = ySyncPluginKey.getState(editor.prosemirrorState) as any;
-    const resolve = (relPos: any) =>
-      relativePositionToAbsolutePosition(
-        fragment.doc!,
-        state.binding.type,
-        Y.createRelativePositionFromJSON(relPos),
-        state.binding.mapping,
-      );
+      // the relative positions must resolve back to the positions we passed in
+      const state = ySyncPluginKey.getState(editor.prosemirrorState) as any;
+      const resolve = (relPos: any) =>
+        relativePositionToAbsolutePosition(
+          fragment.doc!,
+          state.binding.type,
+          Y.createRelativePositionFromJSON(relPos),
+          state.binding.mapping,
+        );
 
-    expect(resolve(yjs.anchor)).toBe(3);
-    expect(resolve(yjs.head)).toBe(8);
+      expect(resolve(yjs.anchor)).toBe(3);
+      expect(resolve(yjs.head)).toBe(8);
+    } finally {
+      editor._tiptapEditor.destroy();
+      doc.destroy();
+    }
   });
 });

packages/core/src/yjs/extensions/YUndo.test.ts

@@ -0,0 +1,84 @@
+import { closeHistory } from "@tiptap/pm/history";
+import {
+  afterEach,
+  beforeEach,
+  describe,
+  expect,
+  it,
+  vi,
+} from "vite-plus/test";
+import { yUndoPluginKey } from "y-prosemirror";
+import * as Y from "yjs";
+
+import { BlockNoteEditor } from "../../editor/BlockNoteEditor.js";
+import { withCollaboration } from "../index.js";
+
+describe("YUndo history boundaries", () => {
+  let doc: Y.Doc;
+  let editor: BlockNoteEditor;
+  let undoManager: Y.UndoManager;
+
+  beforeEach(() => {
+    doc = new Y.Doc();
+    const fragment = doc.getXmlFragment("document");
+    editor = BlockNoteEditor.create(
+      withCollaboration({
+        collaboration: {
+          fragment,
+          user: { name: "Test", color: "#ff0000" },
+          provider: undefined,
+        },
+      }),
+    );
+    editor.mount(document.createElement("div"));
+    const undoState = yUndoPluginKey.getState(editor.prosemirrorState);
+    if (!undoState) {
+      throw new Error("Missing Yjs undo plugin in collaborative test editor");
+    }
+    undoManager = undoState.undoManager;
+    undoManager.clear();
+    undoManager.stopCapturing();
+    // Both edits occur within one capture window, regardless of test speed.
+    vi.spyOn(Date, "now").mockReturnValue(Date.now());
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+    undoManager.destroy();
+    editor._tiptapEditor.destroy();
+    doc.destroy();
+  });
+
+  function insert(value: string) {
+    editor.prosemirrorView.dispatch(
+      editor.prosemirrorState.tr.insertText(value),
+    );
+  }
+
+  it("groups consecutive edits without a history boundary", () => {
+    insert("first");
+    insert("second");
+
+    undoManager.undo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("");
+    expect(undoManager.canUndo()).toBe(false);
+    undoManager.redo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("firstsecond");
+  });
+
+  it("separates edits across closeHistory for undo and redo", () => {
+    insert("first");
+    editor.prosemirrorView.dispatch(closeHistory(editor.prosemirrorState.tr));
+    insert("second");
+
+    undoManager.undo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("first");
+    undoManager.undo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("");
+    expect(undoManager.canUndo()).toBe(false);
+    undoManager.redo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("first");
+    undoManager.redo();
+    expect(editor.prosemirrorState.doc.textContent).toBe("firstsecond");
+  });
+});

packages/core/src/yjs/extensions/YUndo.ts

@@ -1,10 +1,25 @@
+import { Plugin } from "prosemirror-state";
 import { redoCommand, undoCommand, yUndoPlugin } from "y-prosemirror";
 import { createExtension } from "../../editor/BlockNoteExtension.js";
 
 export const YUndoExtension = createExtension(() => {
+  const undoPlugin = yUndoPlugin();
+  const historyBoundaryPlugin = new Plugin({
+    appendTransaction(transactions, _oldState, newState) {
+      // @handlewithcare/prosemirror-inputrules dispatches closeHistory between
+      // inserting the literal trigger and applying its conversion. Yjs doesn't
+      // read that marker, so otherwise both changes enter the same undo item.
+      // prosemirror-history doesn't export the marker's PluginKey; keep this
+      // compatibility dependency here, guarded by the history-boundary tests.
+      if (transactions.some((tr) => tr.getMeta("closeHistory$"))) {
+        undoPlugin.getState(newState)?.undoManager.stopCapturing();
+      }
+      return null;
+    },
+  });
   return {
     key: "yUndo",
-    prosemirrorPlugins: [yUndoPlugin()],
+    prosemirrorPlugins: [undoPlugin, historyBoundaryPlugin],
     dependsOn: ["yCursor", "ySync"],
     undoCommand: undoCommand,
     redoCommand: redoCommand,