Fixed UserPreferencesV0::as_prefstring_bytes

Also added more tests around prefstrings

Signed-off-by: Ben Aaron Goldberg <ben@benaaron.dev>

src/user_preferences/mod.rs

@@ -25,6 +25,7 @@ use data_encoding::BASE32_NOPAD;
 /// Because parsing a prefstring must be done in relation to an [`InstanceSettings`], the
 /// `UserPreferences` struct shares a lifetime with the settings it was created with.
 #[non_exhaustive]
+#[derive(Debug, PartialEq, Eq)]
 pub enum UserPreferences {
 	V0(v0::UserPreferencesV0)
 }
@@ -140,3 +141,15 @@ impl Preference for UserPreferences {
 	    UserPreferences::V0(UserPreferencesV0::from_preferences(prefs))
 	}
 }
+
+#[cfg(test)]
+mod test {
+	use super::*;
+
+	#[test]
+	fn test_prefstring_bytes_round_trip() {
+		let prefs = UserPreferences::default();
+		let bytes = prefs.as_prefstring_bytes();
+		assert_eq!(prefs, UserPreferences::from_prefstring_bytes(&bytes).unwrap());
+	}
+}

src/user_preferences/v0.rs

@@ -125,7 +125,7 @@ impl Preference for UserPreferencesV0 {
 			defaults_byte |= 0b10000000;
 		}
 		defaults_byte |= self.default_weight & 0b01111111;
-		vec![defaults_byte]
+		vec![0, defaults_byte]
 			.into_iter()
 			.chain(self.commands.iter().map(|cmd| cmd.into()))
 			.collect()
@@ -606,4 +606,19 @@ mod tests {
 		let prefs = UserPreferencesV0::from_preferences(&pref_vals);
 		assert_eq!(prefs, expected_prefs);
 	}
+
+	#[test]
+	fn test_as_prefstring_bytes() {
+		let prefs = UserPreferencesV0::default();
+		let expected_bytes = vec![0 , 0b10000001];
+		assert_eq!(expected_bytes, prefs.as_prefstring_bytes());
+	}
+
+	#[test]
+	fn test_from_prefstring_bytes() {
+		let bytes = vec![0 , 0b10000001];
+		let prefs = UserPreferencesV0::from_prefstring_bytes(&bytes).unwrap();
+		let expected_prefs = UserPreferencesV0::default();
+		assert_eq!(expected_prefs, prefs);
+	}
 }