From cb12daa429236a220a37308b5923b5df762bc6b9 Mon Sep 17 00:00:00 2001
From: chh-ay <vinchhaysea30@gmail.com>
Date: Tue, 6 Oct 2026 23:06:10 +0700
Subject: [PATCH] fix(core): paste across hidden columns

---
 .changeset/paste-hidden-columns.md        |  5 +++
 packages/core/src/clipboard-controller.ts |  1 +
 packages/core/test/grid.test.ts           | 40 +++++++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 .changeset/paste-hidden-columns.md

diff --git a/.changeset/paste-hidden-columns.md b/.changeset/paste-hidden-columns.md
new file mode 100644
index 000000000..23781881b
--- /dev/null
+++ b/.changeset/paste-hidden-columns.md
@@ -0,0 +1,5 @@
+---
+"@sheetwrite/core": patch
+---
+
+Fix pasting across hidden columns. Paste into the visible columns, leave hidden cells unchanged, and undo the paste in one step.
diff --git a/packages/core/src/clipboard-controller.ts b/packages/core/src/clipboard-controller.ts
index 6739ab4e3..c3e9c45da 100644
--- a/packages/core/src/clipboard-controller.ts
+++ b/packages/core/src/clipboard-controller.ts
@@ -691,6 +691,7 @@ export class ClipboardController {
       availableRows > 0 &&
       width > 0 &&
       targetCols.length === width &&
+      targetCols.every((col, index) => col === focus.col + index) &&
       Array.from({ length: availableRows }, (_, row) => row).every(
         (row) =>
           widthAt(row) === width && this.deps.toDataRow(focus.row + row) === firstDataRow + row,
diff --git a/packages/core/test/grid.test.ts b/packages/core/test/grid.test.ts
index cbbe574f0..dcb009d8e 100644
--- a/packages/core/test/grid.test.ts
+++ b/packages/core/test/grid.test.ts
@@ -4,6 +4,7 @@ import type { XlsxTableExportBackend } from "../src/export.js";
 import { setXlsxTableExportBackend } from "../src/export.js";
 import {
   AUTO_FIT_CHUNK_CELLS,
+  createGrid,
   DEFAULT_THEME,
   GridImpl,
   initSheetwrite,
@@ -141,6 +142,45 @@ describe("Grid editing (Layer 3)", () => {
     await initSheetwrite();
   });
 
+  it("pastes across hidden columns without changing them and undoes in one step", async () => {
+    const workbook = makeWorkbook(2);
+    const sheet = workbook.sheets[0];
+    const hiddenColumn = sheet?.columns[1];
+    if (!hiddenColumn) throw new Error("expected the amount column in the fixture");
+    hiddenColumn.visible = false;
+    const clipboardDescriptor = Object.getOwnPropertyDescriptor(navigator, "clipboard");
+    Object.defineProperty(navigator, "clipboard", {
+      configurable: true,
+      value: { readText: async () => "Alice\tParis\nBob\tTokyo" },
+    });
+    const grid = createGrid(mountHost(), { workbook, data: makeColumnarData(2) });
+    const changes: ChangeEvent[] = [];
+    grid.on("change", (event) => changes.push(event));
+    const readCells = () =>
+      [0, 1].map((row) =>
+        [0, 1, 2].map((col) => grid.store.getCell({ sheet: "s1", row, col }).resolved),
+      );
+    try {
+      expect(grid.store).toBeInstanceOf(SheetwriteStore);
+      grid.setSelection({ kind: "cell", addr: { sheet: "s1", row: 0, col: 0 } });
+      expect(await grid.actions.paste()).toBe("done");
+      expect(readCells()).toEqual([
+        ["Alice", 0.5, "Paris"],
+        ["Bob", 10.5, "Tokyo"],
+      ]);
+      grid.undo();
+      expect(readCells()).toEqual([
+        ["Customer 0", 0.5, "Phnom Penh"],
+        ["Customer 1", 10.5, "Tokyo"],
+      ]);
+      expect(changes.map((event) => event.commitReason)).toEqual(["paste", "undo"]);
+    } finally {
+      grid.destroy();
+      if (clipboardDescriptor) Object.defineProperty(navigator, "clipboard", clipboardDescriptor);
+      else Reflect.deleteProperty(navigator, "clipboard");
+    }
+  });
+
   it("commits a typed edit through the editor into the store", () => {
     const workbook = makeWorkbook(20);
     const store = new SheetwriteStore(workbook, makeColumnarData(20));