Add test for default values of options and the help subcommand

src/rails_new.rs

@@ -39,3 +39,32 @@ fn arguments_are_directed_to_rails_new() -> Result<(), Box<dyn std::error::Error
 
     Ok(())
 }
+
+#[test]
+fn default_values() -> Result<(), Box<dyn std::error::Error>> {
+    use clap::CommandFactory;
+
+    let m = Cli::command().get_matches_from(vec!["rails-new", "my_app"]);
+
+    let ruby_version = m.get_one::<String>("ruby_version").unwrap();
+    let rails_version = m.get_one::<String>("rails_version").unwrap();
+
+    assert_eq!(ruby_version, "3.2.3");
+    assert_eq!(rails_version, "7.1.3");
+
+    Ok(())
+}
+
+#[test]
+fn rails_help() -> Result<(), Box<dyn std::error::Error>> {
+    use clap::CommandFactory;
+
+    let m = Cli::command().get_matches_from(vec!["rails-new", "rails-help"]);
+
+    match m.subcommand_name() {
+        Some("rails-help") => {}
+        _ => panic!("Expected subcommand 'rails-help'"),
+    }
+
+    Ok(())
+}