check 140 digits for twitter

main.go

@@ -5,10 +5,13 @@ import (
 	"os"
 	"tweetdistributor/discord"
 	"tweetdistributor/output"
+	"unicode/utf8"
 
 	"github.com/bwmarrin/discordgo"
 )
 
+const maxTweetLength = 140
+
 func main() {
 	d := discord.Discord(os.Getenv("DISCORD_TOKEN"), os.Getenv("DISCORD_CHANNEL"))
 
@@ -23,6 +26,12 @@ func main() {
 	outputs = append(outputs, output.BlueskyOutput(os.Getenv("BSKY_IDENTIFIER"), os.Getenv("BSKY_PASSWORD")))
 
 	for tweet := range tweetchannel {
+		if length := utf8.RuneCountInString(tweet.Content); length > maxTweetLength {
+			errstr := fmt.Sprintf("Error: message is %d characters, exceeding the %d character limit; not posted", length, maxTweetLength)
+			fmt.Fprintln(os.Stderr, errstr)
+			d.Write(errstr)
+			continue
+		}
 		for _, output := range outputs {
 			err := output.Write(tweet.Content)
 			if err != nil {