#60 Working on Get/Set methods to access the Msg part slice

Still some tests needed

msg.go

@@ -483,6 +483,11 @@ func (m *Msg) GetGenHeader(h Header) []string {
 	return m.genHeader[h]
 }
 
+// GetParts returns the message parts of the Msg
+func (m *Msg) GetParts() []*Part {
+	return m.parts
+}
+
 // SetBodyString sets the body of the message.
 func (m *Msg) SetBodyString(ct ContentType, b string, o ...PartOption) {
 	buf := bytes.NewBufferString(b)

part.go

@@ -4,7 +4,10 @@
 
 package mail
 
-import "io"
+import (
+	"bytes"
+	"io"
+)
 
 // PartOption returns a function that can be used for grouping Part options
 type PartOption func(*Part)
@@ -16,11 +19,45 @@ type Part struct {
 	w     func(io.Writer) (int64, error)
 }
 
+// GetContent executes the WriteFunc of the Part and returns the content as byte slice
+func (p *Part) GetContent() ([]byte, error) {
+	var b bytes.Buffer
+	if _, err := p.w(&b); err != nil {
+		return nil, err
+	}
+	return b.Bytes(), nil
+}
+
+// GetContentType returns the currently set ContentType of the Part
+func (p *Part) GetContentType() ContentType {
+	return p.ctype
+}
+
+// GetEncoding returns the currently set Encoding of the Part
+func (p *Part) GetEncoding() Encoding {
+	return p.enc
+}
+
+// GetWriteFunc returns the currently set WriterFunc of the Part
+func (p *Part) GetWriteFunc() func(io.Writer) (int64, error) {
+	return p.w
+}
+
+// SetContentType overrides the ContentType of the Part
+func (p *Part) SetContentType(c ContentType) {
+	p.ctype = c
+}
+
 // SetEncoding creates a new mime.WordEncoder based on the encoding setting of the message
 func (p *Part) SetEncoding(e Encoding) {
 	p.enc = e
 }
 
+// SetWriteFunc overrides the WriteFunc of the Part
+func (p *Part) SetWriteFunc(w func(io.Writer) (int64, error)) {
+	p.w = w
+}
+
 // WithPartEncoding overrides the default Part encoding
 func WithPartEncoding(e Encoding) PartOption {
 	return func(p *Part) {

part_test.go

@@ -4,7 +4,11 @@
 
 package mail
 
-import "testing"
+import (
+	"bytes"
+	"fmt"
+	"testing"
+)
 
 // TestPartEncoding tests the WithPartEncoding and Part.SetEncoding methods
 func TestPartEncoding(t *testing.T) {
@@ -38,3 +42,88 @@ func TestPartEncoding(t *testing.T) {
 		})
 	}
 }
+
+// TestPartEncoding tests Part.GetEncoding
+func TestPart_GetEncoding(t *testing.T) {
+	tests := []struct {
+		name string
+		enc  Encoding
+		want string
+	}{
+		{"Part encoding: Base64", EncodingB64, "base64"},
+		{"Part encoding: Quoted-Printable", EncodingQP, "quoted-printable"},
+		{"Part encoding: 8bit", NoEncoding, "8bit"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			m := NewMsg()
+			m.SetBodyString(TypeTextPlain, "This is a test with ümläutß", WithPartEncoding(tt.enc))
+			pl, err := getPartList(m)
+			if err != nil {
+				t.Errorf("failed: %s", err)
+				return
+			}
+			e := pl[0].GetEncoding()
+			if e.String() != tt.want {
+				t.Errorf("Part.GetEncoding failed. Expected: %s, got: %s", tt.want, e.String())
+			}
+		})
+	}
+}
+
+// TestPart_GetContentType tests Part.GetContentType
+func TestPart_GetContentType(t *testing.T) {
+	tests := []struct {
+		name string
+		ct   ContentType
+		want string
+	}{
+		{"ContentType: text/plain", TypeTextPlain, "text/plain"},
+		{"ContentType: text/html", TypeTextHTML, "text/html"},
+		{"ContentType: application/json", "application/json", "application/json"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			m := NewMsg()
+			m.SetBodyString(tt.ct, "This is a test with ümläutß")
+			pl, err := getPartList(m)
+			if err != nil {
+				t.Errorf("failed: %s", err)
+				return
+			}
+			c := pl[0].GetContentType()
+			if string(c) != tt.want {
+				t.Errorf("Part.GetContentType failed. Expected: %s, got: %s", tt.want, string(c))
+			}
+		})
+	}
+}
+
+// TestPart_GetWriteFunc tests Part.GetWriteFunc
+func TestPart_GetWriteFunc(t *testing.T) {
+	c := "This is a test with ümläutß"
+	m := NewMsg()
+	m.SetBodyString(TypeTextPlain, c)
+	pl, err := getPartList(m)
+	if err != nil {
+		t.Errorf("failed: %s", err)
+		return
+	}
+	wf := pl[0].GetWriteFunc()
+	var b bytes.Buffer
+	if _, err := wf(&b); err != nil {
+		t.Errorf("failed to execute writefunc: %s", err)
+	}
+	if b.String() != c {
+		t.Errorf("GetWriteFunc failed. Expected: %s, got: %s", c, b.String())
+	}
+}
+
+// getPartList is a helper function
+func getPartList(m *Msg) ([]*Part, error) {
+	pl := m.GetParts()
+	if len(pl) <= 0 {
+		return nil, fmt.Errorf("Msg.GetParts failed. Part list is empty")
+	}
+	return pl, nil
+}