proper test wiring for example test in github actions

example/caller.go

@@ -34,12 +34,6 @@ func Main() {
 		return
 	}
 
-	if len(os.Args) != 2 {
-		err = fmt.Errorf("usage: %v <username>", os.Args[0])
-		return
-	}
-	username := os.Args[1]
-
 	httpClient := http.Client{
 		Transport: &authedTransport{
 			key:     key,
@@ -48,17 +42,25 @@ func Main() {
 	}
 	graphqlClient := graphql.NewClient("https://api.github.com/graphql", &httpClient)
 
-	viewerResp, err := getViewer(context.Background(), graphqlClient)
-	if err != nil {
-		return
-	}
-	fmt.Println("you are", viewerResp.Viewer.MyName)
+	switch len(os.Args) {
+	case 1:
+		viewerResp, err := getViewer(context.Background(), graphqlClient)
+		if err != nil {
+			return
+		}
+		fmt.Println("you are", viewerResp.Viewer.MyName)
 
-	userResp, err := getUser(context.Background(), graphqlClient, username)
-	if err != nil {
-		return
+	case 2:
+		username := os.Args[1]
+		userResp, err := getUser(context.Background(), graphqlClient, username)
+		if err != nil {
+			return
+		}
+		fmt.Println(username, "is", userResp.User.TheirName)
+
+	default:
+		err = fmt.Errorf("usage: %v [username]", os.Args[0])
 	}
-	fmt.Println(username, "is", userResp.User.TheirName)
 }
 
 //go:generate go run github.com/Khan/genqlient genqlient.yaml