Fixes #5146: Apply maxReadFileLine limit to Excel files

- Modified extractTextFromXLSX to accept maxRows option
- Updated extractTextFromFile to pass row limit to Excel extraction
- Modified readFileTool to apply maxReadFileLine setting to Excel files
- Added comprehensive tests for row limiting functionality
- Excel files now respect the same line limits as regular text files
- Prevents 'input length too long' errors when reading large Excel files

Author: roomote

src/core/tools/readFileTool.ts

@@ -517,11 +517,28 @@ export async function readFileTool(
 				}
 
 				// Handle normal file read
-				const content = await extractTextFromFile(fullPath)
-				const lineRangeAttr = ` lines="1-${totalLines}"`
-				let xmlInfo = totalLines > 0 ? `<content${lineRangeAttr}>\n${content}</content>\n` : `<content/>`
+				const fileExtension = path.extname(relPath).toLowerCase()
+				let content: string
+				let actualLines = totalLines
+
+				// For Excel files, apply maxReadFileLine as row limit
+				if (fileExtension === ".xlsx" && maxReadFileLine > 0) {
+					content = await extractTextFromFile(fullPath, { maxRows: maxReadFileLine })
+					// Count actual lines in the extracted content to get accurate line count
+					actualLines = content.split("\n").length
+				} else {
+					content = await extractTextFromFile(fullPath)
+				}
+
+				const lineRangeAttr = ` lines="1-${actualLines}"`
+				let xmlInfo = actualLines > 0 ? `<content${lineRangeAttr}>\n${content}</content>\n` : `<content/>`
+
+				// Add truncation notice for Excel files if they were limited
+				if (fileExtension === ".xlsx" && maxReadFileLine > 0 && content.includes("[... truncated at")) {
+					xmlInfo += `<notice>Excel file truncated to ${maxReadFileLine} rows. Use line_range if you need to read more data</notice>\n`
+				}
 
-				if (totalLines === 0) {
+				if (actualLines === 0) {
 					xmlInfo += `<notice>File is empty</notice>\n`
 				}
 

src/integrations/misc/__tests__/extract-text-from-xlsx.test.ts

@@ -218,4 +218,98 @@ describe("extractTextFromXLSX", () => {
 			await expect(extractTextFromXLSX("/non/existent/file.xlsx")).rejects.toThrow()
 		})
 	})
+
+	describe("row limiting", () => {
+		it("should respect maxRows option", async () => {
+			const workbook = new ExcelJS.Workbook()
+			const worksheet = workbook.addWorksheet("Sheet1")
+
+			// Add 10 rows of data
+			for (let i = 1; i <= 10; i++) {
+				worksheet.getCell(`A${i}`).value = `Row ${i}`
+				worksheet.getCell(`B${i}`).value = `Data ${i}`
+			}
+
+			const result = await extractTextFromXLSX(workbook, { maxRows: 5 })
+
+			expect(result).toContain("Row 1")
+			expect(result).toContain("Row 5")
+			expect(result).not.toContain("Row 6")
+			expect(result).toContain("[... truncated at 5 total rows across all sheets ...]")
+		})
+
+		it("should not truncate when maxRows is not exceeded", async () => {
+			const workbook = new ExcelJS.Workbook()
+			const worksheet = workbook.addWorksheet("Sheet1")
+
+			// Add 3 rows of data
+			for (let i = 1; i <= 3; i++) {
+				worksheet.getCell(`A${i}`).value = `Row ${i}`
+			}
+
+			const result = await extractTextFromXLSX(workbook, { maxRows: 5 })
+
+			expect(result).toContain("Row 1")
+			expect(result).toContain("Row 3")
+			expect(result).not.toContain("truncated")
+		})
+
+		it("should handle maxRows across multiple sheets", async () => {
+			const workbook = new ExcelJS.Workbook()
+
+			const sheet1 = workbook.addWorksheet("Sheet1")
+			for (let i = 1; i <= 3; i++) {
+				sheet1.getCell(`A${i}`).value = `Sheet1 Row ${i}`
+			}
+
+			const sheet2 = workbook.addWorksheet("Sheet2")
+			for (let i = 1; i <= 3; i++) {
+				sheet2.getCell(`A${i}`).value = `Sheet2 Row ${i}`
+			}
+
+			const result = await extractTextFromXLSX(workbook, { maxRows: 4 })
+
+			expect(result).toContain("Sheet1 Row 1")
+			expect(result).toContain("Sheet1 Row 3")
+			expect(result).toContain("Sheet2 Row 1")
+			expect(result).not.toContain("Sheet2 Row 2")
+			expect(result).toContain("[... truncated at 4 total rows across all sheets ...]")
+		})
+
+		it("should use default limit when no maxRows specified", async () => {
+			const workbook = new ExcelJS.Workbook()
+			const worksheet = workbook.addWorksheet("Sheet1")
+
+			// Add a few rows
+			for (let i = 1; i <= 5; i++) {
+				worksheet.getCell(`A${i}`).value = `Row ${i}`
+			}
+
+			const result = await extractTextFromXLSX(workbook)
+
+			expect(result).toContain("Row 1")
+			expect(result).toContain("Row 5")
+			expect(result).not.toContain("truncated")
+		})
+
+		it("should handle empty rows correctly when counting towards limit", async () => {
+			const workbook = new ExcelJS.Workbook()
+			const worksheet = workbook.addWorksheet("Sheet1")
+
+			// Add rows with some empty ones
+			worksheet.getCell("A1").value = "Row 1"
+			// Row 2 is empty
+			worksheet.getCell("A3").value = "Row 3"
+			worksheet.getCell("A4").value = "Row 4"
+			worksheet.getCell("A5").value = "Row 5"
+
+			const result = await extractTextFromXLSX(workbook, { maxRows: 3 })
+
+			expect(result).toContain("Row 1")
+			expect(result).toContain("Row 3")
+			expect(result).toContain("Row 4")
+			expect(result).not.toContain("Row 5")
+			expect(result).toContain("[... truncated at 3 total rows across all sheets ...]")
+		})
+	})
 })

src/integrations/misc/extract-text-from-xlsx.ts

@@ -1,6 +1,6 @@
 import ExcelJS from "exceljs"
 
-const ROW_LIMIT = 50000
+const DEFAULT_ROW_LIMIT = 50000
 
 function formatCellValue(cell: ExcelJS.Cell): string {
 	const value = cell.value
@@ -40,9 +40,13 @@ function formatCellValue(cell: ExcelJS.Cell): string {
 	return value.toString()
 }
 
-export async function extractTextFromXLSX(filePathOrWorkbook: string | ExcelJS.Workbook): Promise<string> {
+export async function extractTextFromXLSX(
+	filePathOrWorkbook: string | ExcelJS.Workbook,
+	options?: { maxRows?: number },
+): Promise<string> {
 	let workbook: ExcelJS.Workbook
 	let excelText = ""
+	const maxRows = options?.maxRows ?? DEFAULT_ROW_LIMIT
 
 	if (typeof filePathOrWorkbook === "string") {
 		workbook = new ExcelJS.Workbook()
@@ -51,16 +55,24 @@ export async function extractTextFromXLSX(filePathOrWorkbook: string | ExcelJS.W
 		workbook = filePathOrWorkbook
 	}
 
+	let totalRowsProcessed = 0
+	let truncated = false
+
 	workbook.eachSheet((worksheet, sheetId) => {
 		if (worksheet.state === "hidden" || worksheet.state === "veryHidden") {
 			return
 		}
 
+		if (truncated) {
+			return false // Stop processing sheets if we've already truncated
+		}
+
 		excelText += `--- Sheet: ${worksheet.name} ---\n`
 
 		worksheet.eachRow({ includeEmpty: false }, (row, rowNumber) => {
-			if (rowNumber > ROW_LIMIT) {
-				excelText += `[... truncated at row ${rowNumber} ...]\n`
+			if (totalRowsProcessed >= maxRows) {
+				excelText += `[... truncated at ${totalRowsProcessed} total rows across all sheets ...]\n`
+				truncated = true
 				return false
 			}
 
@@ -77,12 +89,15 @@ export async function extractTextFromXLSX(filePathOrWorkbook: string | ExcelJS.W
 
 			if (hasContent) {
 				excelText += rowTexts.join("\t") + "\n"
+				totalRowsProcessed++
 			}
 
 			return true
 		})
 
-		excelText += "\n"
+		if (!truncated) {
+			excelText += "\n"
+		}
 	})
 
 	return excelText.trim()

src/integrations/misc/extract-text.ts

@@ -48,7 +48,7 @@ export function getSupportedBinaryFormats(): string[] {
 	return Object.keys(SUPPORTED_BINARY_FORMATS)
 }
 
-export async function extractTextFromFile(filePath: string): Promise<string> {
+export async function extractTextFromFile(filePath: string, options?: { maxRows?: number }): Promise<string> {
 	try {
 		await fs.access(filePath)
 	} catch (error) {
@@ -60,6 +60,10 @@ export async function extractTextFromFile(filePath: string): Promise<string> {
 	// Check if we have a specific extractor for this format
 	const extractor = SUPPORTED_BINARY_FORMATS[fileExtension as keyof typeof SUPPORTED_BINARY_FORMATS]
 	if (extractor) {
+		// Pass options to Excel extractor, ignore for others
+		if (fileExtension === ".xlsx") {
+			return extractTextFromXLSX(filePath, options)
+		}
 		return extractor(filePath)
 	}