get rid of an unwrap

src/misc.rs

@@ -70,7 +70,8 @@ impl From<roxmltree::Error> for Error {
 /// Returns the current date in YYYY-MM-DD format. Needed for RIS API query to get current version of the overview.
 pub(crate) fn current_date() -> String {
     let local_date = OffsetDateTime::now_utc();
-    let format = format_description::parse("[year]-[month]-[day]").unwrap(); //unwrap okay, supplied format is fine
+    let format = format_description::parse("[year]-[month]-[day]")
+        .expect("Can't fail, supplied format is fine");
     local_date.format(&format).expect("Failed to format date")
 }
 
@@ -80,7 +81,12 @@ pub(crate) fn get_cache_dir() -> Result<String, Error> {
         msg: "directories crate could not find basedirs.".into(),
     })?;
     let cache_dir = cache_dir.cache_dir();
-    Ok(format!("{}/risp/", cache_dir.to_str().unwrap()))
+    Ok(format!(
+        "{}/risp/",
+        cache_dir
+            .to_str()
+            .ok_or(Error::new("Cache dir can't be found"))?
+    ))
 }
 
 #[cfg(test)]