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+import { afterEach, beforeEach, describe, expect, it } from "vite-plus/test";
+
+import { BlockNoteSchema } from "../../blocks/BlockNoteSchema.js";
+import { defaultBlockSpecs } from "../../blocks/defaultBlocks.js";
+import { BlockNoteEditor } from "../../editor/BlockNoteEditor.js";
+import { createBlockSpec } from "../../schema/index.js";
+import { TableHandlesExtension } from "./TableHandles.js";
+
+// Unit tests for the mouse handling in `TableHandlesView`, which decides
+// whether the row/column handles should be attached to the cell under the
+// cursor. It reads the DOM (`getBoundingClientRect`, node views, hit testing),
+// so it runs in the browser suite rather than as a node unit test.
+
+// A custom block which renders a real `<table>` of its own, without having any
+// table content in the document. Table cells like these are indistinguishable
+// from a table block's cells when only looking at the DOM.
+const fakeTableBlock = createBlockSpec(
+  {
+    type: "fakeTable",
+    propSchema: {},
+    content: "none",
+  },
+  {
+    render: () => {
+      const dom = document.createElement("div");
+      dom.className = "fake-table";
+      dom.innerHTML =
+        "<table><tbody><tr><td>Not a real cell</td></tr></tbody></table>";
+
+      return { dom };
+    },
+  },
+);
+
+// A custom block which embeds a second editor, itself containing a table. The
+// nested editor's cells live inside the outer editor's DOM, so they reach the
+// outer editor's mouse handlers, but its block IDs are unknown to the outer
+// document.
+const nestedEditorBlock = createBlockSpec(
+  {
+    type: "nestedEditor",
+    propSchema: {},
+    content: "none",
+  },
+  {
+    render: () => {
+      const dom = document.createElement("div");
+      dom.className = "nested-editor";
+      dom.contentEditable = "false";
+
+      const nestedEditor = BlockNoteEditor.create({
+        initialContent: [
+          {
+            id: "nested-table",
+            type: "table",
+            content: {
+              type: "tableContent",
+              rows: [{ cells: ["Nested cell"] }],
+            },
+          },
+        ],
+      });
+      nestedEditor.mount(dom, { portalTarget: document.body });
+
+      return { dom, destroy: () => nestedEditor.unmount() };
+    },
+  },
+);
+
+const schema = BlockNoteSchema.create({
+  blockSpecs: {
+    ...defaultBlockSpecs,
+    fakeTable: fakeTableBlock(),
+    nestedEditor: nestedEditorBlock(),
+  },
+});
+
+describe("TableHandlesView mouse handling", () => {
+  let editor: BlockNoteEditor<any, any, any>;
+  let mountPoint: HTMLElement;
+
+  beforeEach(() => {
+    mountPoint = document.createElement("div");
+    document.body.appendChild(mountPoint);
+
+    editor = BlockNoteEditor.create({
+      schema,
+      initialContent: [
+        {
+          id: "table-0",
+          type: "table",
+          content: {
+            type: "tableContent",
+            rows: [
+              { cells: ["Cell 1", "Cell 2", "Cell 3"] },
+              { cells: ["Cell 4", "Cell 5", "Cell 6"] },
+            ],
+          },
+        },
+        { id: "paragraph-0", type: "paragraph", content: "Paragraph" },
+        { id: "fake-table-0", type: "fakeTable" },
+        { id: "nested-editor-0", type: "nestedEditor" },
+      ],
+    }) as BlockNoteEditor<any, any, any>;
+    editor.mount(mountPoint);
+  });
+
+  afterEach(() => {
+    editor.unmount();
+    editor._tiptapEditor.destroy();
+    mountPoint.remove();
+  });
+
+  function tableHandlesState() {
+    return editor.getExtension(TableHandlesExtension)!.store.state;
+  }
+
+  function queryElement(selector: string) {
+    const element = mountPoint.querySelector<HTMLElement>(selector);
+    if (!element) {
+      throw new Error(`No element matching "${selector}"`);
+    }
+    return element;
+  }
+
+  // The cell in the (only) real table block, at the given row and column.
+  function tableCell(rowIndex: number, colIndex: number) {
+    const cell = queryElement(
+      `[data-id="table-0"] tbody tr:nth-child(${rowIndex + 1})`,
+    ).children[colIndex];
+    if (!(cell instanceof HTMLElement)) {
+      throw new Error(`No cell at row ${rowIndex}, column ${colIndex}`);
+    }
+    return cell;
+  }
+
+  function dispatchMouseEvent(
+    type: "mousemove" | "mousedown",
+    el: HTMLElement,
+  ) {
+    const rect = el.getBoundingClientRect();
+    el.dispatchEvent(
+      new MouseEvent(type, {
+        bubbles: true,
+        clientX: rect.left + rect.width / 2,
+        clientY: rect.top + rect.height / 2,
+      }),
+    );
+  }
+
+  // Moves the mouse over `el` and asserts the handler survived it. An event
+  // listener that throws doesn't propagate the error to `dispatchEvent`'s
+  // caller - the browser reports it as an `error` event on `window` instead -
+  // so the error has to be picked up from there to be visible to the test.
+  function moveMouseOver(el: HTMLElement) {
+    const errors: unknown[] = [];
+    const collectError = (event: ErrorEvent) => {
+      errors.push(event.error ?? event.message);
+    };
+
+    window.addEventListener("error", collectError);
+    try {
+      dispatchMouseEvent("mousemove", el);
+    } finally {
+      window.removeEventListener("error", collectError);
+    }
+
+    expect(errors).toEqual([]);
+  }
+
+  it("attaches the handles to the hovered cell", () => {
+    moveMouseOver(tableCell(1, 1));
+
+    expect(tableHandlesState()).toMatchObject({
+      show: true,
+      rowIndex: 1,
+      colIndex: 1,
+      block: { id: "table-0" },
+    });
+  });
+
+  it("only offers the add/remove buttons on the last row and column", () => {
+    moveMouseOver(tableCell(0, 0));
+
+    expect(tableHandlesState()).toMatchObject({
+      showAddOrRemoveRowsButton: false,
+      showAddOrRemoveColumnsButton: false,
+    });
+
+    moveMouseOver(tableCell(1, 2));
+
+    expect(tableHandlesState()).toMatchObject({
+      showAddOrRemoveRowsButton: true,
+      showAddOrRemoveColumnsButton: true,
+    });
+  });
+
+  it("hides the handles when the mouse leaves the table", () => {
+    moveMouseOver(tableCell(0, 0));
+    expect(tableHandlesState()?.show).toBe(true);
+
+    moveMouseOver(queryElement('[data-id="paragraph-0"]'));
+
+    expect(tableHandlesState()?.show).toBe(false);
+  });
+
+  it("hides the handles while text is being selected with the mouse", () => {
+    moveMouseOver(tableCell(0, 0));
+    expect(tableHandlesState()?.show).toBe(true);
+
+    dispatchMouseEvent("mousedown", tableCell(0, 0));
+    moveMouseOver(tableCell(0, 1));
+
+    expect(tableHandlesState()?.show).toBe(false);
+  });
+
+  it("keeps the handles on the same cell while frozen", () => {
+    moveMouseOver(tableCell(0, 0));
+    editor.getExtension(TableHandlesExtension)!.freezeHandles();
+
+    moveMouseOver(tableCell(1, 2));
+
+    expect(tableHandlesState()).toMatchObject({
+      show: true,
+      rowIndex: 0,
+      colIndex: 0,
+    });
+
+    editor.getExtension(TableHandlesExtension)!.unfreezeHandles();
+    moveMouseOver(tableCell(1, 2));
+
+    expect(tableHandlesState()).toMatchObject({
+      show: true,
+      rowIndex: 1,
+      colIndex: 2,
+    });
+  });
+
+  it("does not show the handles when the editor is not editable", () => {
+    editor.isEditable = false;
+
+    moveMouseOver(tableCell(0, 0));
+
+    expect(tableHandlesState()?.show).toBeFalsy();
+  });
+
+  // Regression test for https://github.com/TypeCellOS/BlockNote/issues/2964.
+  // The hovered block used to be treated as a table as soon as the schema had
+  // a table block in it, so a custom block rendering a `<table>` ended up on
+  // the table path and crashed on its (absent) table content.
+  it("ignores cells of a custom block that renders its own table", () => {
+    moveMouseOver(queryElement(".fake-table td"));
+
+    expect(tableHandlesState()?.show).toBeFalsy();
+  });
+
+  it("hides the handles when moving from a table onto a custom block's table", () => {
+    moveMouseOver(tableCell(0, 0));
+    expect(tableHandlesState()?.show).toBe(true);
+
+    moveMouseOver(queryElement(".fake-table td"));
+
+    expect(tableHandlesState()?.show).toBe(false);
+  });
+
+  // The other half of #2964: the hovered cell belongs to a nested editor, so
+  // its block ID cannot be resolved in the outer editor's document. That used
+  // to throw `Block with ID <id> not found` on every mouse move.
+  it("ignores table cells belonging to a nested editor", () => {
+    moveMouseOver(queryElement(".nested-editor td"));
+
+    expect(tableHandlesState()?.show).toBeFalsy();
+  });
+
+  it("hides the handles when moving from a table onto a nested editor's table", () => {
+    moveMouseOver(tableCell(0, 0));
+    expect(tableHandlesState()?.show).toBe(true);
+
+    moveMouseOver(queryElement(".nested-editor td"));
+
+    expect(tableHandlesState()?.show).toBe(false);
+  });
+});