Merge pull request #172 from wneessen/feature/171_implement-per-part-…

…charsets

Add Charset support for message parts

msg.go

@@ -1141,6 +1141,7 @@ func (m *Msg) hasPGPType() bool {
 func (m *Msg) newPart(ct ContentType, o ...PartOption) *Part {
  p := &Part{
  ctype: ct,
+ cset: m.charset,
  enc: m.encoding,
  }
 

msgwriter.go

@@ -245,7 +245,11 @@ func (mw *msgWriter) newPart(h map[string][]string) {
 
 // writePart writes the corresponding part to the Msg body
 func (mw *msgWriter) writePart(p *Part, cs Charset) {
- ct := fmt.Sprintf("%s; charset=%s", p.ctype, cs)
+ pcs := p.cset
+ if pcs.String() == "" {
+ pcs = cs
+ }
+ ct := fmt.Sprintf("%s; charset=%s", p.ctype, pcs)
  cte := p.enc.String()
  if mw.d == 0 {
  mw.writeHeader(HeaderContentType, ct)

msgwriter_test.go

@@ -53,6 +53,7 @@ func TestMsgWriter_writeMsg(t *testing.T) {
  m.SetDateWithValue(now)
  m.SetMessageIDWithValue("message@id.com")
  m.SetBodyString(TypeTextPlain, "This is the body")
+ m.AddAlternativeString(TypeTextHTML, "This is the alternative body")
  buf := bytes.Buffer{}
  mw := &msgWriter{w: &buf, c: CharsetUTF8, en: mime.QEncoding}
  mw.writeMsg(m)
@@ -95,6 +96,26 @@ func TestMsgWriter_writeMsg(t *testing.T) {
  if !strings.Contains(ms, "\r\n\r\nThis is the body") {
  ea = append(ea, "Message body")
  }
+
+ pl := m.GetParts()
+ if len(pl) <= 0 {
+ t.Errorf("expected multiple parts but got none")
+ return
+ }
+ if len(pl) == 2 {
+ ap := pl[1]
+ ap.SetCharset(CharsetISO88591)
+ }
+ buf.Reset()
+ mw.writeMsg(m)
+ ms = buf.String()
+ if !strings.Contains(ms, "\r\n\r\nThis is the alternative body") {
+ ea = append(ea, "Message alternative body")
+ }
+ if !strings.Contains(ms, `Content-Type: text/html; charset=ISO-8859-1`) {
+ ea = append(ea, "alternative body charset")
+ }
+
  if len(ea) > 0 {
  em := "writeMsg() failed. The following errors occurred:\n"
  for e := range ea {

part.go

@@ -15,6 +15,7 @@ type PartOption func(*Part)
 // Part is a part of the Msg
 type Part struct {
  ctype ContentType
+ cset Charset
  desc string
  enc Encoding
  del bool
@@ -30,6 +31,11 @@ func (p *Part) GetContent() ([]byte, error) {
  return b.Bytes(), nil
 }
 
+// GetCharset returns the currently set Charset of the Part
+func (p *Part) GetCharset() Charset {
+ return p.cset
+}
+
 // GetContentType returns the currently set ContentType of the Part
 func (p *Part) GetContentType() ContentType {
  return p.ctype
@@ -61,6 +67,11 @@ func (p *Part) SetContentType(c ContentType) {
  p.ctype = c
 }
 
+// SetCharset overrides the Charset of the Part
+func (p *Part) SetCharset(c Charset) {
+ p.cset = c
+}
+
 // SetEncoding creates a new mime.WordEncoder based on the encoding setting of the message
 func (p *Part) SetEncoding(e Encoding) {
  p.enc = e
@@ -82,6 +93,13 @@ func (p *Part) Delete() {
  p.del = true
 }
 
+// WithPartCharset overrides the default Part charset
+func WithPartCharset(c Charset) PartOption {
+ return func(p *Part) {
+ p.cset = c
+ }
+}
+
 // WithPartEncoding overrides the default Part encoding
 func WithPartEncoding(e Encoding) PartOption {
  return func(p *Part) {

part_test.go

@@ -45,6 +45,33 @@ func TestPartEncoding(t *testing.T) {
  }
 }
 
+// TestWithPartCharset tests the WithPartCharset method
+func TestWithPartCharset(t *testing.T) {
+ tests := []struct {
+ name string
+ cs Charset
+ want string
+ }{
+ {"Part charset: UTF-8", CharsetUTF8, "UTF-8"},
+ {"Part charset: ISO-8859-1", CharsetISO88591, "ISO-8859-1"},
+ {"Part charset: empty", "", ""},
+ }
+ for _, tt := range tests {
+ m := NewMsg()
+ t.Run(tt.name, func(t *testing.T) {
+ part := m.newPart(TypeTextPlain, WithPartCharset(tt.cs), nil)
+ if part == nil {
+ t.Errorf("newPart() WithPartCharset() failed: no part returned")
+ return
+ }
+ if part.cset.String() != tt.want {
+ t.Errorf("newPart() WithPartCharset() failed: expected charset: %s, got: %s",
+ tt.want, part.cset.String())
+ }
+ })
+ }
+}
+
 // TestPart_WithPartContentDescription tests the WithPartContentDescription method
 func TestPart_WithPartContentDescription(t *testing.T) {
  tests := []struct {
@@ -320,3 +347,32 @@ func getPartList(m *Msg) ([]*Part, error) {
  }
  return pl, nil
 }
+
+// TestPart_SetCharset tests Part.SetCharset method
+func TestPart_SetCharset(t *testing.T) {
+ tests := []struct {
+ name string
+ cs Charset
+ want string
+ }{
+ {"Charset: UTF-8", CharsetUTF8, "UTF-8"},
+ {"Charset: ISO-8859-1", CharsetISO88591, "ISO-8859-1"},
+ {"Charset: empty", "", ""},
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ m := NewMsg()
+ m.SetBodyString(TypeTextPlain, "This is a test with ümläutß")
+ pl, err := getPartList(m)
+ if err != nil {
+ t.Errorf("failed: %s", err)
+ return
+ }
+ pl[0].SetCharset(tt.cs)
+ cs := pl[0].GetCharset()
+ if string(cs) != tt.want {
+ t.Errorf("SetCharset failed. Got: %s, expected: %s", string(cs), tt.want)
+ }
+ })
+ }
+}