#applySlateOp doesn't properly adjust indices for move_node operations

[ezeidman]

moveNode.ts doesn't properly handle the case when the origin and the target of the move operation are under the same parent and the target node is being moved forward to a later position under the parent.

Repro:

const paragraph: Paragraph = {
  type: "paragraph",
  elementId: "uuid-1",
  children: [
    {
      type: "text",
      text: "",
    },
    {
      type: "user-mention",
      elementId: "uuid-2",
      collaborator: {
        user: "bob",
        type: "user",
      },
      children: [{ text: "" } as any],
    },
    {
      type: "text",
      text: "abc",
    },
    {
      type: "text",
      text: "def",
      bold: true,
    },
  ],
};

describe("move inline forward", () => {
  it("move inline forward", () => {
    const { editor1 } = setupTreeTestEnvironment();

    editor1.apply({
      type: "insert_node",
      node: paragraph,
      path: [0],
    });
    editor1.flushLocalChanges();
    checkSlateMatchesYjs(editor1, createTreeSlateEditor);
    editor1.apply({
      type: "move_node",
      path: [0, 1],
      newPath: [0, 3],
    });
    editor1.flushLocalChanges();
    checkSlateMatchesYjs(editor1, createTreeSlateEditor);
  });
});

[BitPhinix]

Interesting find - happy to look into this in about a week. Super swamped at the moment. Glad to release a new version sooner if you put in a PR with a fix!