Issue #46: Move and rename writer; add comments

3 files changed, 21 insertions, 12 deletions

diff --git a/internal/feed/mail.go b/internal/feed/mail.go
index 0bc7d37..3010bfb 100644
--- a/internal/feed/mail.go
+++ b/internal/feed/mail.go
@@ -23,7 +23,7 @@ import (
 	"github.com/Necoro/feed2imap-go/internal/msg"
 	"github.com/Necoro/feed2imap-go/pkg/config"
 	"github.com/Necoro/feed2imap-go/pkg/log"
-	"github.com/Necoro/feed2imap-go/pkg/util"
+	"github.com/Necoro/feed2imap-go/pkg/rfc822"
 	"github.com/Necoro/feed2imap-go/pkg/version"
 )
 
@@ -98,7 +98,7 @@ func (item *item) writeContentPart(w *message.Writer, typ string, tpl template.T
 	}
 	defer partW.Close()
 
-	if err = tpl.Execute(util.FixWriter(w), item); err != nil {
+	if err = tpl.Execute(rfc822.Writer(w), item); err != nil {
 		return fmt.Errorf("writing %s part: %w", typ, err)
 	}
 
diff --git a/pkg/util/fixWriter.go b/pkg/rfc822/writer.go
index d78b618..07751ea 100644
--- a/pkg/util/fixWriter.go
+++ b/pkg/rfc822/writer.go
@@ -1,15 +1,25 @@
-package util
+// Package rfc822 provides a writer that ensures the intrinsics of RFC 822.
+//
+// Rationale
+//
+// Cyrus IMAP really cares about the hard specifics of RFC 822, namely not allowing single \r and \n.
+//
+// See also: https://www.cyrusimap.org/imap/reference/faqs/interop-barenewlines.html
+// and: https://github.com/Necoro/feed2imap-go/issues/46
+//
+// NB: This package currently only cares about the newlines.
+package rfc822
 
 import "io"
 
-type fixWriter struct {
+type rfc822Writer struct {
 	w io.Writer
 }
 
 var lf = []byte{'\n'}
 var cr = []byte{'\r'}
 
-func (f fixWriter) Write(p []byte) (n int, err error) {
+func (f rfc822Writer) Write(p []byte) (n int, err error) {
 	crFound := false
 	start := 0
 
@@ -56,8 +66,7 @@ func (f fixWriter) Write(p []byte) (n int, err error) {
 	return
 }
 
-// Cyrus IMAP really cares about single \r and \n.
-// Implement this fixer to change them into \r\n.
-func FixWriter(w io.Writer) io.Writer {
-	return fixWriter{w}
+// Writer creates a new RFC 822 conform writer.
+func Writer(w io.Writer) io.Writer {
+	return rfc822Writer{w}
 }
diff --git a/pkg/util/fixWriter_test.go b/pkg/rfc822/writer_test.go
index 91961be..7beae8d 100644
--- a/pkg/util/fixWriter_test.go
+++ b/pkg/rfc822/writer_test.go
@@ -1,4 +1,4 @@
-package util
+package rfc822
 
 import (
 	"bytes"
@@ -6,7 +6,7 @@ import (
 	"testing"
 )
 
-func TestFixWriter_Write(t *testing.T) {
+func TestRfc822Writer_Write(t *testing.T) {
 	tests := []struct {
 		before string
 		after  string
@@ -33,7 +33,7 @@ func TestFixWriter_Write(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.before, func(t *testing.T) {
 			b := bytes.Buffer{}
-			w := FixWriter(&b)
+			w := Writer(&b)
 			if _, err := io.WriteString(w, tt.before); err != nil {
 				t.Errorf("Error: %v", err)
 				return