This closes #1955, refs #119, support to set cell value with an IEEE 754 "not-a-number" value or infinity

cell.go

@@ -15,6 +15,7 @@ import (
 	"bytes"
 	"encoding/xml"
 	"fmt"
+	"math"
 	"os"
 	"reflect"
 	"strconv"
@@ -385,6 +386,9 @@ func setCellBool(value bool) (t string, v string) {
 //	var x float32 = 1.325
 //	f.SetCellFloat("Sheet1", "A1", float64(x), 2, 32)
 func (f *File) SetCellFloat(sheet, cell string, value float64, precision, bitSize int) error {
+	if math.IsNaN(value) || math.IsInf(value, 0) {
+		return f.SetCellStr(sheet, cell, fmt.Sprint(value))
+	}
 	f.mu.Lock()
 	ws, err := f.workSheetReader(sheet)
 	if err != nil {
@@ -399,17 +403,20 @@ func (f *File) SetCellFloat(sheet, cell string, value float64, precision, bitSiz
 		return err
 	}
 	c.S = ws.prepareCellStyle(col, row, c.S)
-	c.T, c.V = setCellFloat(value, precision, bitSize)
-	c.IS = nil
+	c.setCellFloat(value, precision, bitSize)
 	return f.removeFormula(c, ws, sheet)
 }
 
 // setCellFloat prepares cell type and string type cell value by a given float
 // value.
-func setCellFloat(value float64, precision, bitSize int) (t string, v string) {
-	v = strconv.FormatFloat(value, 'f', precision, bitSize)
+func (c *xlsxC) setCellFloat(value float64, precision, bitSize int) {
+	if math.IsNaN(value) || math.IsInf(value, 0) {
+		c.setInlineStr(fmt.Sprint(value))
 		return
 	}
+	c.T, c.V = "", strconv.FormatFloat(value, 'f', precision, bitSize)
+	c.IS = nil
+}
 
 // SetCellStr provides a function to set string type value of a cell. Total
 // number of characters that a cell can contain 32767 characters.

cell_test.go

@@ -292,6 +292,19 @@ func TestSetCellValue(t *testing.T) {
 	val, err = f.GetCellValue("Sheet1", "B1")
 	assert.NoError(t, err)
 	assert.Equal(t, "b", val)
+
+	f = NewFile()
+	// Test set cell value with an IEEE 754 "not-a-number" value or infinity
+	for num, expected := range map[float64]string{
+		math.NaN():   "NaN",
+		math.Inf(0):  "+Inf",
+		math.Inf(-1): "-Inf",
+	} {
+		assert.NoError(t, f.SetCellValue("Sheet1", "A1", num))
+		val, err := f.GetCellValue("Sheet1", "A1")
+		assert.NoError(t, err)
+		assert.Equal(t, expected, val)
+	}
 }
 
 func TestSetCellValues(t *testing.T) {

stream.go

@@ -529,9 +529,9 @@ func (sw *StreamWriter) setCellValFunc(c *xlsxC, val interface{}) error {
 	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64:
 		setCellIntFunc(c, val)
 	case float32:
-		c.T, c.V = setCellFloat(float64(val), -1, 32)
+		c.setCellFloat(float64(val), -1, 32)
 	case float64:
-		c.T, c.V = setCellFloat(val, -1, 64)
+		c.setCellFloat(val, -1, 64)
 	case string:
 		c.setCellValue(val)
 	case []byte:

stream_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io"
+	"math"
 	"math/rand"
 	"os"
 	"path/filepath"
@@ -76,6 +77,8 @@ func TestStreamWriter(t *testing.T) {
 	assert.NoError(t, streamWriter.SetRow("A7", nil, RowOpts{Height: 20, Hidden: true, StyleID: styleID}))
 	assert.Equal(t, ErrMaxRowHeight, streamWriter.SetRow("A8", nil, RowOpts{Height: MaxRowHeight + 1}))
 
+	assert.NoError(t, streamWriter.SetRow("A9", []interface{}{math.NaN(), math.Inf(0), math.Inf(-1)}))
+
 	for rowID := 10; rowID <= 51200; rowID++ {
 		row := make([]interface{}, 50)
 		for colID := 0; colID < 50; colID++ {
@@ -145,7 +148,7 @@ func TestStreamWriter(t *testing.T) {
 		cells += len(row)
 	}
 	assert.NoError(t, rows.Close())
-	assert.Equal(t, 2559559, cells)
+	assert.Equal(t, 2559562, cells)
 	// Save spreadsheet with password.
 	assert.NoError(t, file.SaveAs(filepath.Join("test", "EncryptionTestStreamWriter.xlsx"), Options{Password: "password"}))
 	assert.NoError(t, file.Close())