Fix company cards import crash by transposing spreadsheet data densely

src/libs/actions/ImportSpreadsheet.ts

@@ -37,7 +37,7 @@ function setSpreadsheetData(
     const numColumns = firstRow.length;
 
     // Transpose data from row-major to column-major format
-    const transposedData: string[][] = firstRow.map((_, colIndex) => data.map((row) => String(row.at(colIndex) ?? '')));
+    const transposedData: string[][] = Array.from({length: numColumns}, (_, colIndex) => data.map((row) => String(row.at(colIndex) ?? '')));
 
     const columnNames: Record<number, string> = {};
     for (let colIndex = 0; colIndex < numColumns; colIndex++) {

tests/unit/ImportSpreadsheetTest.ts

@@ -0,0 +1,130 @@
+import {setSpreadsheetData} from '@libs/actions/ImportSpreadsheet';
+
+import CONST from '@src/CONST';
+import ONYXKEYS from '@src/ONYXKEYS';
+import type ImportedSpreadsheet from '@src/types/onyx/ImportedSpreadsheet';
+
+import Onyx from 'react-native-onyx';
+
+/**
+ * Builds a sparse row, mirroring what `XLSX.utils.sheet_to_json(worksheet, {header: 1})` returns for a sheet with a
+ * blank column: the missing cell is left as an array *hole*, not as `undefined`.
+ */
+function buildSparseRow(cells: string[], holeIndexes: number[]): string[] {
+    const row = new Array<string>(cells.length);
+    for (const [index, cell] of cells.entries()) {
+        if (holeIndexes.includes(index)) {
+            continue;
+        }
+        row[index] = cell;
+    }
+    return row;
+}
+
+function isImportedSpreadsheet(value: unknown): value is ImportedSpreadsheet {
+    return typeof value === 'object' && !!value && 'data' in value;
+}
+
+/** Replays the column-major to row-major transpose the company cards import runs when Import is pressed. */
+function transposeBackToRows(columns: string[][]): string[][] {
+    const rows: string[][] = [];
+    for (let rowIndex = 0; rowIndex < (columns.at(0)?.length ?? 0); rowIndex++) {
+        const row: string[] = [];
+        for (const column of columns) {
+            row.push(column.at(rowIndex) ?? '');
+        }
+        rows.push(row);
+    }
+    return rows;
+}
+
+describe('ImportSpreadsheet', () => {
+    describe('setSpreadsheetData', () => {
+        let storedSpreadsheet: ImportedSpreadsheet | undefined;
+
+        beforeEach(() => {
+            storedSpreadsheet = undefined;
+            jest.spyOn(Onyx, 'set').mockImplementation((key, value) => {
+                if (key === ONYXKEYS.IMPORTED_SPREADSHEET && isImportedSpreadsheet(value)) {
+                    storedSpreadsheet = value;
+                }
+                return Promise.resolve();
+            });
+        });
+
+        afterEach(() => {
+            jest.restoreAllMocks();
+        });
+
+        async function importData(data: string[][]) {
+            await setSpreadsheetData(data, 'file://spreadsheet.csv', 'text/csv', 'spreadsheet.csv', false);
+            expect(storedSpreadsheet).toBeDefined();
+            return storedSpreadsheet;
+        }
+
+        it('transposes dense data to column-major format', async () => {
+            const spreadsheet = await importData([
+                ['Date', 'Merchant', 'Amount'],
+                ['2026-07-21', 'Starbucks', '10'],
+                ['2026-07-22', 'Amazon', '20'],
+            ]);
+
+            expect(spreadsheet?.data).toEqual([
+                ['Date', '2026-07-21', '2026-07-22'],
+                ['Merchant', 'Starbucks', 'Amazon'],
+                ['Amount', '10', '20'],
+            ]);
+            expect(Object.values(spreadsheet?.columns ?? {})).toEqual([CONST.CSV_IMPORT_COLUMNS.IGNORE, CONST.CSV_IMPORT_COLUMNS.IGNORE, CONST.CSV_IMPORT_COLUMNS.IGNORE]);
+        });
+
+        it('produces a dense column for a blank column in the header row', async () => {
+            const spreadsheet = await importData([buildSparseRow(['Date', '', 'Amount'], [1]), buildSparseRow(['2026-07-21', '', '10'], [1])]);
+
+            expect(spreadsheet?.data).toEqual([
+                ['Date', '2026-07-21'],
+                ['', ''],
+                ['Amount', '10'],
+            ]);
+            // Object.keys skips array holes, so this only matches the length when every index holds a real column
+            expect(Object.keys(spreadsheet?.data ?? []).length).toBe(spreadsheet?.data?.length);
+        });
+
+        it('keeps the column count in sync with the generated column roles', async () => {
+            const spreadsheet = await importData([buildSparseRow(['Date', '', '', 'Amount'], [1, 2]), buildSparseRow(['2026-07-21', '', '', '10'], [1, 2])]);
+
+            expect(spreadsheet?.data?.length).toBe(4);
+            expect(Object.keys(spreadsheet?.data ?? []).length).toBe(4);
+            expect(Object.keys(spreadsheet?.columns ?? {}).length).toBe(4);
+        });
+
+        it('lets the company cards import transpose the data back without throwing', async () => {
+            const spreadsheet = await importData([buildSparseRow(['Date', '', 'Amount'], [1]), buildSparseRow(['2026-07-21', '', '10'], [1]), buildSparseRow(['2026-07-22', '', '20'], [1])]);
+
+            expect(transposeBackToRows(spreadsheet?.data ?? [])).toEqual([
+                ['Date', '', 'Amount'],
+                ['2026-07-21', '', '10'],
+                ['2026-07-22', '', '20'],
+            ]);
+        });
+
+        it('pads ragged rows so every column has one cell per row', async () => {
+            const spreadsheet = await importData([
+                ['Date', 'Merchant', 'Amount'],
+                ['2026-07-21', 'Starbucks'],
+            ]);
+
+            expect(spreadsheet?.data).toEqual([
+                ['Date', '2026-07-21'],
+                ['Merchant', 'Starbucks'],
+                ['Amount', ''],
+            ]);
+        });
+
+        it('rejects data that does not have at least a header and one row', async () => {
+            await expect(setSpreadsheetData([['Date', 'Amount']], 'file://spreadsheet.csv', 'text/csv', 'spreadsheet.csv', false)).rejects.toThrow(
+                'Invalid data format: file must contain at least 2 rows',
+            );
+            expect(storedSpreadsheet).toBeUndefined();
+        });
+    });
+});