eml.go

@@ -112,8 +112,26 @@ func parseEMLHeaders(mailHeader *netmail.Header, msg *Msg) error {
 	}
 
 	// Extract content type, charset and encoding first
-	parseEMLEncoding(mailHeader, msg)
+	if value := mailHeader.Get(HeaderContentTransferEnc.String()); value != "" {
-	parseEMLContentTypeCharset(mailHeader, msg)
+		switch {
+		case strings.EqualFold(value, EncodingQP.String()):
+			msg.SetEncoding(EncodingQP)
+		case strings.EqualFold(value, EncodingB64.String()):
+			msg.SetEncoding(EncodingB64)
+		default:
+			msg.SetEncoding(NoEncoding)
+		}
+	}
+	if value := mailHeader.Get(HeaderContentType.String()); value != "" {
+		contentType, charSet := parseContentType(value)
+		if charSet != "" {
+			msg.SetCharset(Charset(charSet))
+		}
+		msg.setEncoder()
+		if contentType != "" {
+			msg.SetGenHeader(HeaderContentType, contentType)
+		}
+	}
 
 	// Extract address headers
 	if value := mailHeader.Get(HeaderFrom.String()); value != "" {
@@ -184,8 +202,8 @@ func parseEMLBodyParts(parsedMsg *netmail.Message, bodybuf *bytes.Buffer, msg *M
 			return fmt.Errorf("failed to parse plain body: %w", err)
 		}
 	case strings.EqualFold(mediatype, TypeMultipartAlternative.String()),
-		strings.EqualFold(mediatype, TypeMultipartMixed.String()):
+		strings.EqualFold(mediatype, "multipart/mixed"):
-		if err = parseEMLMultipart(params, bodybuf, msg); err != nil {
+		if err = parseEMLMultipartAlternative(params, bodybuf, msg); err != nil {
 			return fmt.Errorf("failed to parse multipart/alternative body: %w", err)
 		}
 	default:
@@ -224,32 +242,18 @@ func parseEMLBodyPlain(mediatype string, parsedMsg *netmail.Message, bodybuf *by
 	return fmt.Errorf("unsupported Content-Transfer-Encoding")
 }
 
-// parseEMLMultipart parses a multipart body part of a EML
+// parseEMLMultipartAlternative parses a multipart/alternative body part of a EML
-func parseEMLMultipart(params map[string]string, bodybuf *bytes.Buffer, msg *Msg) error {
+func parseEMLMultipartAlternative(params map[string]string, bodybuf *bytes.Buffer, msg *Msg) error {
 	boundary, ok := params["boundary"]
 	if !ok {
 		return fmt.Errorf("no boundary tag found in multipart body")
 	}
 	multipartReader := multipart.NewReader(bodybuf, boundary)
-ReadNextPart:
 	multiPart, err := multipartReader.NextPart()
-	defer func() {
+	if err != nil {
-		if multiPart != nil {
-			_ = multiPart.Close()
-		}
-	}()
-	if err != nil && !errors.Is(err, io.EOF) {
 		return fmt.Errorf("failed to get next part of multipart message: %w", err)
 	}
 	for err == nil {
-		// Content-Disposition header means we have an attachment or embed
-		if contentDisposition, ok := multiPart.Header[HeaderContentDisposition.String()]; ok {
-			if err := parseEMLAttachmentEmbed(contentDisposition, multiPart, msg); err != nil {
-				return fmt.Errorf("failed to parse attachment/embed: %w", err)
-			}
-			goto ReadNextPart
-		}
-
 		multiPartData, mperr := io.ReadAll(multiPart)
 		if mperr != nil {
 			_ = multiPart.Close()
@@ -260,11 +264,9 @@ ReadNextPart:
 		if !ok {
 			return fmt.Errorf("failed to get content-type from part")
 		}
-		contentType, optional := parseMultiPartHeader(multiPartContentType[0])
+		contentType, charSet := parseContentType(multiPartContentType[0])
-		part := msg.newPart(ContentType(contentType))
+		p := msg.newPart(ContentType(contentType))
-		if charset, ok := optional["charset"]; ok {
+		p.SetCharset(Charset(charSet))
-			part.SetCharset(Charset(charset))
-		}
 
 		mutliPartTransferEnc, ok := multiPart.Header[HeaderContentTransferEnc.String()]
 		if !ok {
@@ -276,52 +278,25 @@ ReadNextPart:
 
 		switch {
 		case strings.EqualFold(mutliPartTransferEnc[0], EncodingB64.String()):
-			if err := handleEMLMultiPartBase64Encoding(multiPartData, part); err != nil {
+			if err := handleEMLMultiPartBase64Encoding(multiPartData, p); err != nil {
 				return fmt.Errorf("failed to handle multipart base64 transfer-encoding: %w", err)
 			}
 		case strings.EqualFold(mutliPartTransferEnc[0], EncodingQP.String()):
-			part.SetContent(string(multiPartData))
+			p.SetContent(string(multiPartData))
 		default:
 			return fmt.Errorf("unsupported Content-Transfer-Encoding")
 		}
 
-		msg.parts = append(msg.parts, part)
+		msg.parts = append(msg.parts, p)
 		multiPart, err = multipartReader.NextPart()
 	}
 	if !errors.Is(err, io.EOF) {
+		_ = multiPart.Close()
 		return fmt.Errorf("failed to read multipart: %w", err)
 	}
 	return nil
 }
 
-// parseEMLEncoding parses and determines the encoding of the message
-func parseEMLEncoding(mailHeader *netmail.Header, msg *Msg) {
-	if value := mailHeader.Get(HeaderContentTransferEnc.String()); value != "" {
-		switch {
-		case strings.EqualFold(value, EncodingQP.String()):
-			msg.SetEncoding(EncodingQP)
-		case strings.EqualFold(value, EncodingB64.String()):
-			msg.SetEncoding(EncodingB64)
-		default:
-			msg.SetEncoding(NoEncoding)
-		}
-	}
-}
-
-// parseEMLContentTypeCharset parses and determines the charset and content type of the message
-func parseEMLContentTypeCharset(mailHeader *netmail.Header, msg *Msg) {
-	if value := mailHeader.Get(HeaderContentType.String()); value != "" {
-		contentType, optional := parseMultiPartHeader(value)
-		if charset, ok := optional["charset"]; ok {
-			msg.SetCharset(Charset(charset))
-		}
-		msg.setEncoder()
-		if contentType != "" {
-			msg.SetGenHeader(HeaderContentType, contentType)
-		}
-	}
-}
-
 // handleEMLMultiPartBase64Encoding sets the content body of a base64 encoded Part
 func handleEMLMultiPartBase64Encoding(multiPartData []byte, part *Part) error {
 	part.SetEncoding(EncodingB64)
@@ -333,37 +308,19 @@ func handleEMLMultiPartBase64Encoding(multiPartData []byte, part *Part) error {
 	return nil
 }
 
-// parseMultiPartHeader parses a multipart header and returns the value and optional parts as
+// parseContentType parses the Content-Type header and returns the type and charse as
-// separate map
+// separate string values
-func parseMultiPartHeader(multiPartHeader string) (header string, optional map[string]string) {
+func parseContentType(contentTypeHeader string) (contentType string, charSet string) {
-	optional = make(map[string]string)
+	contentTypeSplit := strings.SplitN(contentTypeHeader, "; ", 2)
-	headerSplit := strings.SplitN(multiPartHeader, "; ", 2)
+	if len(contentTypeSplit) != 2 {
-	header = headerSplit[0]
+		return
-	if len(headerSplit) == 2 {
+	}
-		optSplit := strings.SplitN(headerSplit[1], "=", 2)
+	contentType = contentTypeSplit[0]
-		if len(optSplit) == 2 {
+	if strings.HasPrefix(strings.ToLower(contentTypeSplit[1]), "charset=") {
-			optional[optSplit[0]] = optSplit[1]
+		charSetSplit := strings.SplitN(contentTypeSplit[1], "=", 2)
+		if len(charSetSplit) == 2 {
+			charSet = charSetSplit[1]
 		}
 	}
 	return
 }
-
-// parseEMLAttachmentEmbed parses a multipart that is an attachment or embed
-func parseEMLAttachmentEmbed(contentDisposition []string, multiPart *multipart.Part, msg *Msg) error {
-	cdType, optional := parseMultiPartHeader(contentDisposition[0])
-	filename := "generic.attachment"
-	if name, ok := optional["filename"]; ok {
-		filename = name[1 : len(name)-1]
-	}
-	switch strings.ToLower(cdType) {
-	case "attachment":
-		if err := msg.AttachReader(filename, multiPart); err != nil {
-			return fmt.Errorf("failed to attach multipart body: %w", err)
-		}
-	case "inline":
-		if err := msg.EmbedReader(filename, multiPart); err != nil {
-			return fmt.Errorf("failed to embed multipart body: %w", err)
-		}
-	}
-	return nil
-}

eml_test.go

@@ -5,8 +5,6 @@
 package mail
 
 import (
-	"fmt"
-	"os"
 	"strings"
 	"testing"
 	"time"
@@ -121,37 +119,6 @@ RGVhciBDdXN0b21lciwKClRoaXMgaXMgYSB0ZXN0IG1haWwuIFBsZWFzZSBkbyBub3QgcmVwbHkg
 dG8gdGhpcy4gQWxzbyB0aGlzIGxpbmUgaXMgdmVyeSBsb25nIHNvIGl0CnNob3VsZCBiZSB3cmFw
 cGVkLgoKClRoYW5rIHlvdXIgZm9yIHlvdXIgYnVzaW5lc3MhClRoZSBnby1tYWlsIHRlYW0KCi0t
 ClRoaXMgaXMgYSBzaWduYXR1cmU=`
-	exampleMailPlainB64WithAttachment = `Date: Wed, 01 Nov 2023 00:00:00 +0000
-MIME-Version: 1.0
-Message-ID: <1305604950.683004066175.AAAAAAAAaaaaaaaaB@go-mail.dev>
-Subject: Example mail // plain text base64 with attachment
-User-Agent: go-mail v0.4.1 // https://github.com/wneessen/go-mail
-X-Mailer: go-mail v0.4.1 // https://github.com/wneessen/go-mail
-From: "Toni Tester" <go-mail@go-mail.dev>
-To: <go-mail+test@go-mail.dev>
-Cc: <go-mail+cc@go-mail.dev>
-Content-Type: multipart/mixed;
- boundary=45c75ff528359022eb03679fbe91877d75343f2e1f8193e349deffa33ff7
-
---45c75ff528359022eb03679fbe91877d75343f2e1f8193e349deffa33ff7
-Content-Transfer-Encoding: base64
-Content-Type: text/plain; charset=UTF-8
-
-RGVhciBDdXN0b21lciwKClRoaXMgaXMgYSB0ZXN0IG1haWwuIFBsZWFzZSBkbyBub3QgcmVwbHkg
-dG8gdGhpcy4gQWxzbyB0aGlzIGxpbmUgaXMgdmVyeSBsb25nIHNvIGl0CnNob3VsZCBiZSB3cmFw
-cGVkLgoKClRoYW5rIHlvdXIgZm9yIHlvdXIgYnVzaW5lc3MhClRoZSBnby1tYWlsIHRlYW0KCi0t
-ClRoaXMgaXMgYSBzaWduYXR1cmU=
-
---45c75ff528359022eb03679fbe91877d75343f2e1f8193e349deffa33ff7
-Content-Disposition: attachment; filename="test.attachment"
-Content-Transfer-Encoding: base64
-Content-Type: application/octet-stream; name="test.attachment"
-
-VGhpcyBpcyBhIHNpbXBsZSB0ZXN0IHRleHQgZmlsZSBhdHRhY2htZW50LgoKSXQgCiAgaGFzCiAg
-ICAgc2V2ZXJhbAogICAgICAgICAgICBuZXdsaW5lcwoJICAgICAgICAgICAgYW5kCgkgICAgc3Bh
-Y2VzCiAgICAgaW4KICBpdAouCgpBcyB3ZWxsIGFzIGFuIGVtb2ppOiDwn5mCCg==
-
---45c75ff528359022eb03679fbe91877d75343f2e1f8193e349deffa33ff7--`
 )
 
 func TestEMLToMsgFromString(t *testing.T) {
@@ -176,68 +143,15 @@ func TestEMLToMsgFromString(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			msg, err := EMLToMsgFromString(tt.eml)
+			m, err := EMLToMsgFromString(tt.eml)
 			if err != nil {
 				t.Errorf("failed to parse EML: %s", err)
 			}
-			if msg.Encoding() != tt.enc {
+			if m.Encoding() != tt.enc {
-				t.Errorf("EMLToMsgFromString failed: expected encoding: %s, but got: %s", tt.enc, msg.Encoding())
+				t.Errorf("EMLToMsgFromString failed: expected encoding: %s, but got: %s", tt.enc, m.Encoding())
 			}
-			if subject := msg.GetGenHeader(HeaderSubject); len(subject) > 0 && !strings.EqualFold(subject[0], tt.sub) {
+			if s := m.GetGenHeader(HeaderSubject); len(s) > 0 && !strings.EqualFold(s[0], tt.sub) {
-				t.Errorf("EMLToMsgFromString failed: expected subject: %s, but got: %s",
+				t.Errorf("EMLToMsgFromString failed: expected subject: %s, but got: %s", tt.sub, s[0])
-					tt.sub, subject[0])
-			}
-		})
-	}
-}
-
-func TestEMLToMsgFromFile(t *testing.T) {
-	tests := []struct {
-		name string
-		eml  string
-		enc  string
-		sub  string
-	}{
-		{
-			"Plain text no encoding", exampleMailPlainNoEnc, "8bit",
-			"Example mail // plain text without encoding",
-		},
-		{
-			"Plain text quoted-printable", exampleMailPlainQP, "quoted-printable",
-			"Example mail // plain text quoted-printable",
-		},
-		{
-			"Plain text base64", exampleMailPlainB64, "base64",
-			"Example mail // plain text base64",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			tempDir, err := os.MkdirTemp("", fmt.Sprintf("*-%s", tt.name))
-			if err != nil {
-				t.Errorf("failed to create temp dir: %s", err)
-				return
-			}
-			defer func() {
-				if err = os.RemoveAll(tempDir); err != nil {
-					t.Error("failed to remove temp dir:", err)
-				}
-			}()
-			err = os.WriteFile(fmt.Sprintf("%s/%s.eml", tempDir, tt.name), []byte(tt.eml), 0666)
-			if err != nil {
-				t.Error("failed to write mail to temp file:", err)
-				return
-			}
-			msg, err := EMLToMsgFromFile(fmt.Sprintf("%s/%s.eml", tempDir, tt.name))
-			if err != nil {
-				t.Errorf("failed to parse EML: %s", err)
-			}
-			if msg.Encoding() != tt.enc {
-				t.Errorf("EMLToMsgFromString failed: expected encoding: %s, but got: %s", tt.enc, msg.Encoding())
-			}
-			if subject := msg.GetGenHeader(HeaderSubject); len(subject) > 0 && !strings.EqualFold(subject[0], tt.sub) {
-				t.Errorf("EMLToMsgFromString failed: expected subject: %s, but got: %s",
-					tt.sub, subject[0])
 			}
 		})
 	}
@@ -263,33 +177,3 @@ func TestEMLToMsgFromStringBrokenDate(t *testing.T) {
 		t.Errorf("EML with no date expected: %s, got: %s", now.Format(time.RFC1123Z), d)
 	}
 }
-
-func TestEMLToMsgFromStringWithAttachment(t *testing.T) {
-	wantSubject := "Example mail // plain text base64 with attachment"
-	msg, err := EMLToMsgFromString(exampleMailPlainB64WithAttachment)
-	if err != nil {
-		t.Errorf("EML with attachment failed: %s", err)
-	}
-	if subject := msg.GetGenHeader(HeaderSubject); len(subject) > 0 && !strings.EqualFold(subject[0], wantSubject) {
-		t.Errorf("EMLToMsgFromString of EML with attachment failed: expected subject: %s, but got: %s",
-			wantSubject, subject[0])
-	}
-	if len(msg.attachments) != 1 {
-		t.Errorf("EMLToMsgFromString of EML with attachment failed: expected no. of attachments: %d, but got: %d",
-			1, len(msg.attachments))
-	}
-	contentTypeHeader := msg.GetGenHeader(HeaderContentType)
-	if len(contentTypeHeader) != 1 {
-		t.Errorf("EMLToMsgFromString of EML with attachment failed: expected no. of content-type header: %d, "+
-			"but got: %d", 1, len(contentTypeHeader))
-	}
-	contentTypeSplit := strings.SplitN(contentTypeHeader[0], "; ", 2)
-	if len(contentTypeSplit) != 2 {
-		t.Error("failed to split Content-Type header")
-		return
-	}
-	if !strings.EqualFold(contentTypeSplit[0], "multipart/mixed") {
-		t.Errorf("EMLToMsgFromString of EML with attachment failed: expected content-type: %s, "+
-			"but got: %s", "multipart/mixed", contentTypeSplit[0])
-	}
-}