feat: specify whether URL sources are both missing or both present

1 files changed, 7 insertions, 2 deletions

diff --git a/main.go b/main.go
index b48f6c9..565a2c9 100644
--- a/main.go
+++ b/main.go
@@ -3,7 +3,6 @@
 package main
 
 import (
-	"errors"
 	"flag"
 	"fmt"
 	"log"
@@ -70,7 +69,13 @@ func chooseFrom(urlArg, shortcode, shortcodeFilename string) (string, error) {
 	shortcodeAbsent := (shortcode == "")
 
 	if urlAbsent == shortcodeAbsent {
-		return "", errors.New("-url and -shortcode flags either both missing or both present")
+		messageSlug := "present"
+
+		if urlAbsent {
+			messageSlug = "missing; need exactly one"
+		}
+
+		return "", fmt.Errorf("-url and -shortcode flags both %s", messageSlug)
 	}
 
 	if urlAbsent {