fix(data-grid): apply improvements from code review findings

src/components/data-grid/data-grid-cell-variants.tsx

@@ -63,7 +63,7 @@ export function ShortTextCell<TData>({
   const [value, setValue] = React.useState(initialValue);
   const cellRef = React.useRef<HTMLDivElement>(null);
   const containerRef = React.useRef<HTMLDivElement>(null);
-  const prevIsEditingRef = React.useRef(isEditing);
+  const prevIsEditingRef = React.useRef(false);
 
   const prevInitialValueRef = React.useRef(initialValue);
   if (initialValue !== prevInitialValueRef.current) {
@@ -428,7 +428,7 @@ export function NumberCell<TData>({
   const max = numberCellOpts?.max;
   const step = numberCellOpts?.step;
 
-  const prevIsEditingRef = React.useRef(isEditing);
+  const prevIsEditingRef = React.useRef(false);
 
   const prevInitialValueRef = React.useRef(initialValue);
   if (initialValue !== prevInitialValueRef.current) {
@@ -550,7 +550,7 @@ export function UrlCell<TData>({
   const [value, setValue] = React.useState(initialValue ?? "");
   const cellRef = React.useRef<HTMLDivElement>(null);
   const containerRef = React.useRef<HTMLDivElement>(null);
-  const prevIsEditingRef = React.useRef(isEditing);
+  const prevIsEditingRef = React.useRef(false);
 
   const prevInitialValueRef = React.useRef(initialValue);
   if (initialValue !== prevInitialValueRef.current) {

src/hooks/test/use-data-grid.test.tsx

@@ -1166,6 +1166,51 @@ describe("useDataGrid", () => {
     });
 
     it("should preserve multiline content within cells when pasting", async () => {
+      const onPaste = vi.fn().mockResolvedValue(undefined);
+      mockClipboard.readText.mockResolvedValue(
+        'Alice\tKickflip\t95\nBob\t"Trick with\nmultiple\nlines"\t98',
+      );
+
+      const { result } = renderHook(
+        () =>
+          useDataGrid({
+            data: testData,
+            columns: testColumns,
+            onPaste,
+          }),
+        { wrapper: createWrapper() },
+      );
+
+      act(() => {
+        result.current.tableMeta.onCellClick?.(0, "name");
+      });
+
+      await act(async () => {
+        await result.current.tableMeta.onCellsPaste?.();
+      });
+
+      expect(onPaste).toHaveBeenCalledWith(
+        expect.arrayContaining([
+          expect.objectContaining({
+            rowIndex: 0,
+            columnId: "score",
+            value: 95,
+          }),
+          expect.objectContaining({
+            rowIndex: 1,
+            columnId: "trick",
+            value: "Trick with\nmultiple\nlines",
+          }),
+          expect.objectContaining({
+            rowIndex: 1,
+            columnId: "score",
+            value: 98,
+          }),
+        ]),
+      );
+    });
+
+    it("should preserve unquoted multiline content when pasting (Excel format)", async () => {
       const onPaste = vi.fn().mockResolvedValue(undefined);
       mockClipboard.readText.mockResolvedValue(
         "Alice\tKickflip\t95\nBob\tTrick with\nmultiple\nlines\t98",

src/hooks/use-data-grid.ts

@@ -406,7 +406,7 @@ function useDataGrid<TData>({
         const existingRow = currentData[i];
 
         if (!existingRow) {
-          newData[i] = {} as TData;
+          newData[i] = existingRow as TData;
           continue;
         }
 
@@ -1950,14 +1950,18 @@ function useDataGrid<TData>({
       const currentState = store.getState();
       const rows = tableRef.current?.getRowModel().rows ?? [];
       const currentRowIndex = rows.findIndex((r) => r.id === rowId);
-      const currentRow = currentRowIndex >= 0 ? rows[currentRowIndex] : null;
-      if (!currentRow) return;
+      if (currentRowIndex === -1) return;
 
       if (shiftKey && currentState.lastClickedRowId !== null) {
         const lastClickedRowIndex = rows.findIndex(
           (r) => r.id === currentState.lastClickedRowId,
         );
-        if (lastClickedRowIndex >= 0) {
+        if (lastClickedRowIndex === -1) {
+          onRowSelectionChange({
+            ...currentState.rowSelection,
+            [rowId]: selected,
+          });
+        } else {
           const startIndex = Math.min(lastClickedRowIndex, currentRowIndex);
           const endIndex = Math.max(lastClickedRowIndex, currentRowIndex);
 
@@ -1973,16 +1977,11 @@ function useDataGrid<TData>({
           }
 
           onRowSelectionChange(newRowSelection);
-        } else {
-          onRowSelectionChange({
-            ...currentState.rowSelection,
-            [currentRow.id]: selected,
-          });
         }
       } else {
         onRowSelectionChange({
           ...currentState.rowSelection,
-          [currentRow.id]: selected,
+          [rowId]: selected,
         });
       }
 

src/lib/data-grid.ts

@@ -266,6 +266,67 @@ export function parseTsv(
   text: string,
   fallbackColumnCount: number,
 ): string[][] {
+  if (text.startsWith('"') || text.includes('\t"')) {
+    const rows: string[][] = [];
+    let currentRow: string[] = [];
+    let currentField = "";
+    let inQuotes = false;
+    let i = 0;
+
+    while (i < text.length) {
+      const char = text[i];
+      const nextChar = text[i + 1];
+
+      if (inQuotes) {
+        if (char === '"' && nextChar === '"') {
+          currentField += '"';
+          i += 2;
+        } else if (char === '"') {
+          inQuotes = false;
+          i++;
+        } else {
+          currentField += char;
+          i++;
+        }
+      } else {
+        if (char === '"' && currentField === "") {
+          inQuotes = true;
+          i++;
+        } else if (char === "\t") {
+          currentRow.push(currentField);
+          currentField = "";
+          i++;
+        } else if (char === "\n") {
+          currentRow.push(currentField);
+          if (currentRow.length > 1 || currentRow.some((f) => f.length > 0)) {
+            rows.push(currentRow);
+          }
+          currentRow = [];
+          currentField = "";
+          i++;
+        } else if (char === "\r" && nextChar === "\n") {
+          currentRow.push(currentField);
+          if (currentRow.length > 1 || currentRow.some((f) => f.length > 0)) {
+            rows.push(currentRow);
+          }
+          currentRow = [];
+          currentField = "";
+          i += 2;
+        } else {
+          currentField += char;
+          i++;
+        }
+      }
+    }
+
+    currentRow.push(currentField);
+    if (currentRow.length > 1 || currentRow.some((f) => f.length > 0)) {
+      rows.push(currentRow);
+    }
+
+    return rows;
+  }
+
   const lines = text.split("\n");
   let maxTabs = 0;
   for (const line of lines) {
@@ -277,26 +338,28 @@ export function parseTsv(
 
   const rows: string[][] = [];
   let buf = "";
+  let bufTabs = 0;
 
   for (const line of lines) {
     const tc = countTabs(line);
 
     if (tc === cols - 1) {
-      if (buf && countTabs(buf) === cols - 1) rows.push(buf.split("\t"));
+      if (buf && bufTabs === cols - 1) rows.push(buf.split("\t"));
       buf = "";
+      bufTabs = 0;
       rows.push(line.split("\t"));
-    } else if (tc === 0 && rows.length > 0 && !buf) {
-      const last = rows[rows.length - 1];
-      if (last) {
-        const cell = last[cols - 1];
-        if (cell !== undefined) last[cols - 1] = `${cell}\n${line}`;
-      }
     } else {
       buf = buf ? `${buf}\n${line}` : line;
+      bufTabs += tc;
+      if (bufTabs === cols - 1) {
+        rows.push(buf.split("\t"));
+        buf = "";
+        bufTabs = 0;
+      }
     }
   }
 
-  if (buf && countTabs(buf) === cols - 1) rows.push(buf.split("\t"));
+  if (buf && bufTabs === cols - 1) rows.push(buf.split("\t"));
 
   return rows.length > 0
     ? rows

src/lib/test/data-grid.test.ts

@@ -0,0 +1,140 @@
+import { describe, expect, it } from "vitest";
+import { parseTsv } from "@/lib/data-grid";
+
+describe("parseTsv", () => {
+  describe("basic parsing", () => {
+    it("should parse simple single-row TSV", () => {
+      expect(parseTsv("Alice\tKickflip\t95", 3)).toEqual([
+        ["Alice", "Kickflip", "95"],
+      ]);
+    });
+
+    it("should parse multiple rows", () => {
+      expect(parseTsv("Alice\tKickflip\t95\nBob\tOllie\t88", 3)).toEqual([
+        ["Alice", "Kickflip", "95"],
+        ["Bob", "Ollie", "88"],
+      ]);
+    });
+
+    it("should handle single-column paste", () => {
+      expect(parseTsv("Alice\nBob\nCharlie", 1)).toEqual([
+        ["Alice"],
+        ["Bob"],
+        ["Charlie"],
+      ]);
+    });
+
+    it("should skip empty rows", () => {
+      expect(parseTsv("Alice\tKickflip\t95\n\nBob\tOllie\t88", 3)).toEqual([
+        ["Alice", "Kickflip", "95"],
+        ["Bob", "Ollie", "88"],
+      ]);
+    });
+  });
+
+  describe("quoted fields (standard TSV)", () => {
+    it("should handle quoted multiline content", () => {
+      const text =
+        'Alice\tKickflip\t95\nBob\t"Trick with\nmultiple\nlines"\t98';
+      expect(parseTsv(text, 3)).toEqual([
+        ["Alice", "Kickflip", "95"],
+        ["Bob", "Trick with\nmultiple\nlines", "98"],
+      ]);
+    });
+
+    it("should handle escaped quotes", () => {
+      const text = '"She said ""hello"""\t42';
+      expect(parseTsv(text, 2)).toEqual([['She said "hello"', "42"]]);
+    });
+
+    it("should handle Windows line endings", () => {
+      const text = '"Line 1\r\nLine 2"\tvalue';
+      expect(parseTsv(text, 2)).toEqual([["Line 1\r\nLine 2", "value"]]);
+    });
+
+    it("should handle mixed quoted and unquoted fields", () => {
+      const text = 'plain\t"quoted\nfield"\t123';
+      expect(parseTsv(text, 3)).toEqual([["plain", "quoted\nfield", "123"]]);
+    });
+  });
+
+  describe("unquoted multiline (tab counting)", () => {
+    it("should handle multiline in last column", () => {
+      const text = "Alice\tKickflip\t95\nBob\tTrick with\nmultiple\nlines\t98";
+      expect(parseTsv(text, 3)).toEqual([
+        ["Alice", "Kickflip", "95"],
+        ["Bob", "Trick with\nmultiple\nlines", "98"],
+      ]);
+    });
+
+    it("should handle multiline in middle column", () => {
+      const text =
+        "Alice\tShort note\t95\nBob\tLine 1\nLine 2\nLine 3\t88\nCharlie\tSimple\t77";
+      expect(parseTsv(text, 3)).toEqual([
+        ["Alice", "Short note", "95"],
+        ["Bob", "Line 1\nLine 2\nLine 3", "88"],
+        ["Charlie", "Simple", "77"],
+      ]);
+    });
+
+    it("should handle multiple rows with multiline in middle columns", () => {
+      const text = [
+        "Alice\tShort\t1",
+        "Bob\tMulti",
+        "line",
+        "content\t2",
+        "Charlie\tAnother",
+        "multi\t3",
+        "Dave\tPlain\t4",
+      ].join("\n");
+      expect(parseTsv(text, 3)).toEqual([
+        ["Alice", "Short", "1"],
+        ["Bob", "Multi\nline\ncontent", "2"],
+        ["Charlie", "Another\nmulti", "3"],
+        ["Dave", "Plain", "4"],
+      ]);
+    });
+  });
+
+  describe("data with JSON values (no false positives)", () => {
+    it("should use tab counting when quotes are inside field values not delimiters", () => {
+      const text = 'Alice\t["React","Node.js"]\t95\nBob\t["Python"]\t88';
+      expect(parseTsv(text, 3)).toEqual([
+        ["Alice", '["React","Node.js"]', "95"],
+        ["Bob", '["Python"]', "88"],
+      ]);
+    });
+
+    it("should handle JSON values with unquoted multiline", () => {
+      const text = [
+        'Alice\tShort note\t["React"]\t1',
+        "Bob\tLine 1",
+        'Line 2\t["Python"]\t2',
+        'Charlie\tPlain\t["SQL"]\t3',
+      ].join("\n");
+      expect(parseTsv(text, 4)).toEqual([
+        ["Alice", "Short note", '["React"]', "1"],
+        ["Bob", "Line 1\nLine 2", '["Python"]', "2"],
+        ["Charlie", "Plain", '["SQL"]', "3"],
+      ]);
+    });
+  });
+
+  describe("edge cases", () => {
+    it("should return empty array for empty string", () => {
+      expect(parseTsv("", 0)).toEqual([]);
+    });
+
+    it("should handle single cell", () => {
+      expect(parseTsv("hello", 1)).toEqual([["hello"]]);
+    });
+
+    it("should fallback to simple split when no tabs detected", () => {
+      expect(parseTsv("line1\nline2\nline3", 1)).toEqual([
+        ["line1"],
+        ["line2"],
+        ["line3"],
+      ]);
+    });
+  });
+});