What version of Go are you using (go version)?

1.20

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

Playground

What did you do?

Used the csv.Writer to write-out a string with a CRLF.

What did you expect to see?

The same string, but with the CR dropped; just LF.

What did you see instead?

The exact same string, the CRLF.

The documentation makes the blanket assertion:

Carriage returns before newline characters are silently removed.

Yet the single-field record, []string{" foo1 \r\n foo2 "} will be written-out as " foo1 \r\n foo2 ", and not " foo1 \n foo2 " as I interpret the documentation (and #22746).

package main

import (
	"encoding/csv"
	"fmt"
	"strings"
)

func main() {
	var b strings.Builder
	w := csv.NewWriter(&b)
	w.Write([]string{" foo1 \r\n foo2 "})
	w.Flush()

	want := " foo1 \n foo2 "
	got := b.String()
	got = got[1 : len(got)-2] // trim field quotes

	fmt.Printf("%q != %q", got, want)
}

Prints:

" foo1 \r\n foo2 " != " foo1 \n foo2 "

I use the term "blanket assertion" because that documentation doesn't differentiate between reading and writing, so I expect—and especially after reading #22746—the csv package to effectively disallow a carriage return (CR, \r).

Does the documentation need clarification? Is this a bug with the Writer?