implemented language tag (please review this first)

consume_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"reflect"
+	"strings"
 	"testing"
 
 	"github.com/kr/pretty"
@@ -403,3 +404,37 @@ func TestAtomUnmarshal(t *testing.T) {
 		t.Error("object was not unmarshalled correctly")
 	}
 }
+
+func TestRssFeedLanguageSerialization(t *testing.T) {
+	// Case 1: No language set (empty)
+	feed := &RssFeed{
+		Title:       "Test Feed",
+		Link:        "http://example.com",
+		Description: "Test Description",
+	}
+
+	// Marshal just the feed (channel)
+	bytes, err := xml.Marshal(feed)
+	if err != nil {
+		t.Fatalf("Failed to marshal feed without language: %v", err)
+	}
+	xmlStr := string(bytes)
+
+	if strings.Contains(xmlStr, "<language>") {
+		t.Errorf("Expected no <language> tag when empty, but found: %s", xmlStr)
+	}
+
+	// Case 2: Language set to "en"
+	feed.Language = "en"
+
+	bytes, err = xml.Marshal(feed)
+	if err != nil {
+		t.Fatalf("Failed to marshal feed with language: %v", err)
+	}
+	xmlStr = string(bytes)
+
+	expected := "<language>en</language>"
+	if !strings.Contains(xmlStr, expected) {
+		t.Errorf("Expected %q in output, got: %s", expected, xmlStr)
+	}
+}

language.go

@@ -0,0 +1,21 @@
+package feeds
+
+import (
+	"encoding/xml"
+	"errors"
+	"regexp"
+)
+
+var iso639Regex = regexp.MustCompile(`^[a-z]{2,3}(-[a-zA-Z0-9-]+)?$`)
+
+type ISO639Code string
+
+func (c ISO639Code) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	if c == "" {
+		return nil
+	}
+	if !iso639Regex.MatchString(string(c)) {
+		return errors.New("invalid ISO 639 code")
+	}
+	return e.EncodeElement(string(c), start)
+}

language_test.go

@@ -0,0 +1,85 @@
+package feeds
+
+import (
+	"encoding/xml"
+	"testing"
+)
+
+type LanguageTestStruct struct {
+	XMLName  xml.Name   `xml:"test"`
+	Language ISO639Code `xml:"language"`
+}
+
+func TestISO639CodeMarshalXML(t *testing.T) {
+	tests := []struct {
+		name    string
+		code    ISO639Code
+		wantXML string
+		wantErr bool
+	}{
+		{
+			name:    "valid code en",
+			code:    "en",
+			wantXML: "<test><language>en</language></test>",
+			wantErr: false,
+		},
+		{
+			name:    "valid code de",
+			code:    "de",
+			wantXML: "<test><language>de</language></test>",
+			wantErr: false,
+		},
+		{
+			name:    "valid code de-AT",
+			code:    "de-AT",
+			wantXML: "<test><language>de-AT</language></test>",
+			wantErr: false,
+		},
+		{
+			name:    "valid code en-us",
+			code:    "en-us",
+			wantXML: "<test><language>en-us</language></test>",
+			wantErr: false,
+		},
+		{
+			name:    "valid code eng",
+			code:    "eng",
+			wantXML: "<test><language>eng</language></test>",
+			wantErr: false,
+		},
+		{
+			name:    "invalid code case",
+			code:    "EN",
+			wantXML: "",
+			wantErr: true,
+		},
+		{
+			name:    "invalid code numeric",
+			code:    "12",
+			wantXML: "",
+			wantErr: true,
+		},
+		{
+			name:    "empty code",
+			code:    "",
+			wantXML: "<test></test>",
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := LanguageTestStruct{Language: tt.code}
+			bytes, err := xml.Marshal(s)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("MarshalXML() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !tt.wantErr {
+				if string(bytes) != tt.wantXML {
+					t.Errorf("MarshalXML() got = %s, want %s", string(bytes), tt.wantXML)
+				}
+			}
+		})
+	}
+}

rss.go

@@ -41,34 +41,35 @@ type RssTextInput struct {
 }
 
 type RssFeed struct {
-	XMLName        xml.Name `xml:"channel"`
-	Title          string   `xml:"title"`       // required
-	Link           string   `xml:"link"`        // required
-	Description    string   `xml:"description"` // required
-	Language       string   `xml:"language,omitempty"`
-	Copyright      string   `xml:"copyright,omitempty"`
-	ManagingEditor string   `xml:"managingEditor,omitempty"` // Author used
-	WebMaster      string   `xml:"webMaster,omitempty"`
-	PubDate        string   `xml:"pubDate,omitempty"`       // created or updated
-	LastBuildDate  string   `xml:"lastBuildDate,omitempty"` // updated used
-	Category       string   `xml:"category,omitempty"`
-	Generator      string   `xml:"generator,omitempty"`
-	Docs           string   `xml:"docs,omitempty"`
-	Cloud          string   `xml:"cloud,omitempty"`
-	Ttl            int      `xml:"ttl,omitempty"`
-	Rating         string   `xml:"rating,omitempty"`
-	SkipHours      string   `xml:"skipHours,omitempty"`
-	SkipDays       string   `xml:"skipDays,omitempty"`
+	XMLName        xml.Name   `xml:"channel"`
+	Title          string     `xml:"title"`       // required
+	Link           string     `xml:"link"`        // required
+	Description    string     `xml:"description"` // required
+	Language       ISO639Code `xml:"language,omitempty"`
+	Copyright      string     `xml:"copyright,omitempty"`
+	ManagingEditor string     `xml:"managingEditor,omitempty"` // Author used
+	WebMaster      string     `xml:"webMaster,omitempty"`
+	PubDate        string     `xml:"pubDate,omitempty"`       // created or updated
+	LastBuildDate  string     `xml:"lastBuildDate,omitempty"` // updated used
+	Category       string     `xml:"category,omitempty"`
+	Generator      string     `xml:"generator,omitempty"`
+	Docs           string     `xml:"docs,omitempty"`
+	Cloud          string     `xml:"cloud,omitempty"`
+	Ttl            int        `xml:"ttl,omitempty"`
+	Rating         string     `xml:"rating,omitempty"`
+	SkipHours      string     `xml:"skipHours,omitempty"`
+	SkipDays       string     `xml:"skipDays,omitempty"`
 	Image          *RssImage
 	TextInput      *RssTextInput
 	Items          []*RssItem `xml:"item"`
 }
 
 type RssItem struct {
 	XMLName     xml.Name `xml:"item"`
-	Title       string   `xml:"title"`       // required
-	Link        string   `xml:"link"`        // required
-	Description string   `xml:"description"` // required
+	Title       string   `xml:"title"`              // required
+	Link        string   `xml:"link"`               // required
+	Description string   `xml:"description"`        // required
+	Language    string   `xml:"language,omitempty"` //
 	Content     *RssContent
 	Author      string `xml:"author,omitempty"`
 	Category    string `xml:"category,omitempty"`

to-implement.md

@@ -16,5 +16,4 @@
 <itunes:owner>
 <itunes:subtitle>
 <itunes:summary>
-<language>
 ```