Moved the logic to append and write.

helper/README.md

@@ -152,7 +152,7 @@ fmt.Println(actual) // [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
 ```
 
 <a name="AppendOrWriteToCsvFile"></a>
-## func [AppendOrWriteToCsvFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L294>)
+## func [AppendOrWriteToCsvFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L287>)
 
 ```go
 func AppendOrWriteToCsvFile[T any](fileName string, hasHeader bool, rows <-chan *T) error
@@ -553,7 +553,7 @@ fmt.Println(helper.ChanToSlice(squared)) // [4, 9, 25, 100]
 ```
 
 <a name="ReadFromCsvFile"></a>
-## func [ReadFromCsvFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L281>)
+## func [ReadFromCsvFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L274>)
 
 ```go
 func ReadFromCsvFile[T any](fileName string, hasHeader bool) (<-chan *T, error)
@@ -863,7 +863,7 @@ func (c *Csv[T]) ReadFromReader(reader io.Reader) <-chan *T
 ReadFromReader parses the CSV data from the provided reader, maps the data to corresponding struct fields, and delivers the resulting it through the channel.
 
 <a name="Csv[T].WriteToFile"></a>
-### func \(\*Csv\[T\]\) [WriteToFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L176>)
+### func \(\*Csv\[T\]\) [WriteToFile](<https://github.com/cinar/indicator/blob/v2/helper/csv.go#L186>)
 
 ```go
 func (c *Csv[T]) WriteToFile(fileName string, rows <-chan *T) error

helper/csv.go

@@ -168,13 +168,33 @@ func (c *Csv[T]) ReadFromFile(fileName string) (<-chan *T, error) {
 // file's column order matches the field order of the given row struct to ensure consistent
 // data structure.
 func (c *Csv[T]) AppendToFile(fileName string, rows <-chan *T) error {
-	return c.writeToFileWithFlag(fileName, true, rows)
+	file, err := os.OpenFile(filepath.Clean(fileName), os.O_APPEND|os.O_WRONLY, 0600)
+	if err != nil {
+		return err
+	}
+
+	err = c.writeToWriter(file, false, rows)
+	if err != nil {
+		return err
+	}
+
+	return file.Close()
 }
 
 // WriteToFile creates a new file with the given name and writes the provided rows
 // of data to it, overwriting any existing content.
 func (c *Csv[T]) WriteToFile(fileName string, rows <-chan *T) error {
-	return c.writeToFileWithFlag(fileName, false, rows)
+	file, err := os.OpenFile(filepath.Clean(fileName), os.O_CREATE|os.O_WRONLY, 0600)
+	if err != nil {
+		return err
+	}
+
+	err = c.writeToWriter(file, true, rows)
+	if err != nil {
+		return err
+	}
+
+	return file.Close()
 }
 
 // updateColumnIndexes aligns column indices to match the order of column headers.
@@ -201,33 +221,6 @@ func (c *Csv[T]) updateColumnIndexes(csvReader *csv.Reader) error {
 	return nil
 }
 
-// writeToFileWithFlag writes the provided rows of data to a file with the given name, using the
-// specified flag mode for precise control over file opening and writing behavior.
-func (c *Csv[T]) writeToFileWithFlag(fileName string, appendRows bool, rows <-chan *T) error {
-	var file *os.File
-	var err error
-
-	// Gosec complains if flag is a variable.
-	if appendRows {
-		file, err = os.OpenFile(filepath.Clean(fileName), os.O_APPEND|os.O_WRONLY, 0600)
-	} else {
-		file, err = os.OpenFile(filepath.Clean(fileName), os.O_CREATE|os.O_WRONLY, 0600)
-	}
-
-	if err != nil {
-		return err
-	}
-
-	writeHeader := c.hasHeader && !appendRows
-
-	err = c.writeToWriter(file, writeHeader, rows)
-	if err != nil {
-		return err
-	}
-
-	return file.Close()
-}
-
 // writeToWriter writes the provided rows of data to the specified writer, with the option
 // to include or exclude headers for flexibility in data presentation.
 func (c *Csv[T]) writeToWriter(writer io.Writer, writeHeader bool, rows <-chan *T) error {