Use fully quoted CSV writer for changes.csv

util/csv.go

@@ -0,0 +1,71 @@
+// This file is Free Software under the MIT License
+// without warranty, see README.md and LICENSES/MIT.txt for details.
+//
+// SPDX-License-Identifier: MIT
+//
+// SPDX-FileCopyrightText: 2022 German Federal Office for Information Security (BSI) <https://www.bsi.bund.de>
+// Software-Engineering: 2022 Intevation GmbH <https://intevation.de>
+
+package util
+
+import (
+	"bufio"
+	"io"
+	"strings"
+)
+
+// FullyQuotedCSVWriter implements a CSV writer
+// which puts each field in double quotes (").
+type FullyQuotedCSVWriter struct {
+	// Comma is the separator between fields. Defaults to ','.
+	Comma rune
+	// UseCRLF indicates if "\r\n" should be used for line separation.
+	UseCRLF bool
+	w       *bufio.Writer
+}
+
+// NewFullyQuotedCSWWriter returns a new writer that writes to w.
+func NewFullyQuotedCSWWriter(w io.Writer) *FullyQuotedCSVWriter {
+	return &FullyQuotedCSVWriter{
+		Comma: ',',
+		w:     bufio.NewWriter(w),
+	}
+}
+
+// Write writes a single CSV record to w along with any necessary quoting.
+// A record is a slice of strings with each string being one field.
+// Writes are buffered, so Flush must eventually be called to ensure
+// that the record is written to the underlying io.Writer.
+func (fqcw *FullyQuotedCSVWriter) Write(record []string) error {
+
+	for i, field := range record {
+		if i > 0 {
+			fqcw.w.WriteRune(fqcw.Comma)
+		}
+		fqcw.w.WriteByte('"')
+		if !fqcw.UseCRLF {
+			field = strings.ReplaceAll(field, "\r\n", "\n")
+		}
+		fqcw.w.WriteString(strings.ReplaceAll(field, `"`, `""`))
+		fqcw.w.WriteByte('"')
+	}
+	var err error
+	if fqcw.UseCRLF {
+		_, err = fqcw.w.WriteString("\r\n")
+	} else {
+		err = fqcw.w.WriteByte('\n')
+	}
+	return err
+}
+
+// Flush writes any buffered data to the underlying io.Writer.
+// To check if an error occurred during the Flush, call Error.
+func (fqcw *FullyQuotedCSVWriter) Flush() {
+	fqcw.w.Flush()
+}
+
+// Error reports any error that has occurred during a previous Write or Flush.
+func (fqcw *FullyQuotedCSVWriter) Error() error {
+	_, err := fqcw.w.Write(nil)
+	return err
+}