check authentication at the start of download-or-update-course-exercises

Author: Heliozoa

tmc-client/src/tmc_client.rs

@@ -56,7 +56,7 @@ struct TmcCore {
 // TODO: cache API results?
 impl TmcClient {
     /// Convenience function for checking authentication.
-    fn require_authentication(&self) -> Result<(), ClientError> {
+    pub fn require_authentication(&self) -> Result<(), ClientError> {
         if self.0.token.is_some() {
             Ok(())
         } else {

tmc-langs/src/lib.rs

@@ -208,6 +208,7 @@ pub fn paste_exercise(
 }
 
 /// Downloads the given exercises, by either downloading the exercise template, updating the exercise or downloading an old submission.
+/// Requires authentication.
 /// If the exercise doesn't exist on disk yet...
 ///   if there are previous submissions and download_template is not set, the latest submission is downloaded.
 ///   otherwise, the exercise template is downloaded.
@@ -223,6 +224,8 @@ pub fn download_or_update_course_exercises(
         projects_dir.display()
     );
 
+    client.require_authentication()?;
+
     let exercises_details = client.get_exercises_details(exercises)?;
     let projects_config = ProjectsConfig::load(projects_dir)?;