Don't request viewer_metadata when getting info by link

newsletter.go

@@ -159,11 +159,11 @@ type respGetNewsletterInfo struct {
 	Newsletter *types.NewsletterMetadata `json:"xwa2_newsletter"`
 }
 
-func (cli *Client) getNewsletterInfo(input map[string]any) (*types.NewsletterMetadata, error) {
+func (cli *Client) getNewsletterInfo(input map[string]any, fetchViewerMeta bool) (*types.NewsletterMetadata, error) {
 	data, err := cli.sendMexIQ(context.TODO(), queryFetchNewsletter, map[string]any{
 		"fetch_creation_time":   true,
 		"fetch_full_image":      true,
-		"fetch_viewer_metadata": true,
+		"fetch_viewer_metadata": fetchViewerMeta,
 		"input":                 input,
 	})
 	if err != nil {
@@ -182,17 +182,19 @@ func (cli *Client) GetNewsletterInfo(jid types.JID) (*types.NewsletterMetadata,
 	return cli.getNewsletterInfo(map[string]any{
 		"key":  jid.String(),
 		"type": types.NewsletterKeyTypeJID,
-	})
+	}, true)
 }
 
 // GetNewsletterInfoWithInvite gets the info of a newsletter with an invite link.
 //
 // You can either pass the full link (https://whatsapp.com/channel/...) or just the `...` part.
+//
+// Note that the ViewerMeta field of the returned NewsletterMetadata will be nil.
 func (cli *Client) GetNewsletterInfoWithInvite(key string) (*types.NewsletterMetadata, error) {
 	return cli.getNewsletterInfo(map[string]any{
 		"key":  strings.TrimPrefix(key, NewsletterLinkPrefix),
 		"type": types.NewsletterKeyTypeInvite,
-	})
+	}, false)
 }
 
 type CreateNewsletterParams struct {

types/newsletter.go

@@ -97,10 +97,10 @@ const (
 )
 
 type NewsletterMetadata struct {
-	ID         JID                      `json:"id"`
-	State      WrappedNewsletterState   `json:"state"`
-	ThreadMeta NewsletterThreadMetadata `json:"thread_metadata"`
-	ViewerMeta NewsletterViewerMetadata `json:"viewer_metadata"`
+	ID         JID                       `json:"id"`
+	State      WrappedNewsletterState    `json:"state"`
+	ThreadMeta NewsletterThreadMetadata  `json:"thread_metadata"`
+	ViewerMeta *NewsletterViewerMetadata `json:"viewer_metadata"`
 }
 
 type NewsletterViewerMetadata struct {