Repository navigation
writeXlsx and writeXlsxStream format a styled cell in a formatted column differently #616
Description
What happens
A column with a number format, and a cell in it with its own style that doesn't mention a number format:
const columns = [{ numFmt: "0.00" }]
const own = { font: { bold: true } }
// writeXlsx
writeXlsx({ sheets: [{ name: "S", columns, rows: [[1.5]], cells: new Map([["0,0", { value: 1.5, style: own }]]) }] })
// writeXlsxStream
writeXlsxStream([[{ value: 1.5, style: own }]], { name: "S", columns })The two writers give A1 different formats:
| writer | A1's xf |
Excel shows |
|---|---|---|
writeXlsx |
bold, numFmtId="0" (General) |
1.5 |
writeXlsxStream |
bold, numFmtId="164" (0.00) |
1.50 |
writeXlsx uses the cell's own style as is, so the column's format is dropped. The stream writer's RowSerializer.serializeRow adds the column's numFmt to any style that has none, but not the column's font, fill or anything else.
Expected
Both writers resolve a cell's format the same way. Which way is right is a design choice:
- Own style replaces the column's (what
writeXlsxdoes): simple, but a bold cell in a currency column loses its currency format. - Own style layered over the column's: closer to Excel, where a cell in a formatted column keeps the column's format when you make it bold. The stream writer half-does this, for
numFmtonly.
Repro (main at c991ad0)
Write the two workbooks above and compare <c r="A1" s="…"> and its xf in xl/styles.xml.
Where
resolveRows / columnCellStyle in src/xlsx/worksheet-writer.ts, and RowSerializer.serializeRow in src/xlsx/stream-writer.ts.
Note
#612 (row formats) adds a row style between the cell and the column. It keeps this existing difference as it is, rather than half-fixing it there.
Activity
ronistrom commentedon Oct 21, 2026
A second difference between the two writers, also about column formats:
writeXlsxStreamnever writes a column's style onto<col>. The cells it writes do get the style, so the rows you streamed look right. But a cell typed into the column later doesn't get the format, and the column comes back without its style when the file is read.<col>readStyles: truewriteXlsx<col min="1" max="1" width="12" customWidth="true" style="1"/>s="1"{ width: 12, style: { numFmt: "\"$\"#,##0.00" } }writeXlsxStream<col min="1" max="1" width="12" customWidth="true"/>s="1"{ width: 12 }main at c991ad0.
buildSheetPreludeinsrc/xlsx/stream-writer.tswriteswidth,hiddenandoutlineLevelon<col>but notstyle, and it writes no<col>at all for a column with only a style or anumFmt. The buffered writer has done both since #439 §W. CodeRabbit raised this while reviewing #614. That PR only touches the<col>width, so it leaves this alone.fix(xlsx): resolve a styled cell in a formatted column the same in bo…