rust: handle invalid pattern selection reasons

rust/agama-lib/src/software.rs

@@ -5,6 +5,6 @@ pub mod proxies;
 mod settings;
 mod store;
 
-pub use client::{Pattern, SelectedBy, SoftwareClient};
+pub use client::{Pattern, SelectedBy, SoftwareClient, UnknownSelectedBy};
 pub use settings::SoftwareSettings;
 pub use store::SoftwareStore;

rust/agama-lib/src/software/client.rs

@@ -22,7 +22,7 @@ pub struct Pattern {
 }
 
 /// Represents the reason why a pattern is selected.
-#[derive(Clone, Copy, Debug, Serialize)]
+#[derive(Clone, Copy, Debug, PartialEq, Serialize)]
 pub enum SelectedBy {
     /// The pattern was selected by the user.
     User = 0,
@@ -32,12 +32,18 @@ pub enum SelectedBy {
     None = 2,
 }
 
-impl From<u8> for SelectedBy {
-    fn from(value: u8) -> Self {
+#[derive(Debug, thiserror::Error)]
+#[error("Unknown selected by value: '{0}'")]
+pub struct UnknownSelectedBy(u8);
+
+impl TryFrom<u8> for SelectedBy {
+    type Error = UnknownSelectedBy;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
         match value {
-            0 => Self::User,
-            1 => Self::Auto,
-            _ => Self::None,
+            0 => Ok(Self::User),
+            1 => Ok(Self::Auto),
+            _ => Err(UnknownSelectedBy(value)),
         }
     }
 }
@@ -83,8 +89,14 @@ impl<'a> SoftwareClient<'a> {
             .selected_patterns()
             .await?
             .into_iter()
-            .filter(|(_id, reason)| *reason == SelectedBy::User as u8)
-            .map(|(id, _reason)| id)
+            .filter_map(|(id, reason)| match SelectedBy::try_from(reason) {
+                Ok(reason) if reason == SelectedBy::User => Some(id),
+                Ok(_reason) => None,
+                Err(e) => {
+                    log::warn!("Ignoring pattern {}. Error: {}", &id, e);
+                    None
+                }
+            })
             .collect();
         Ok(patterns)
     }
@@ -94,7 +106,13 @@ impl<'a> SoftwareClient<'a> {
         let patterns = self.software_proxy.selected_patterns().await?;
         let patterns = patterns
             .into_iter()
-            .map(|(id, reason)| (id, reason.into()))
+            .filter_map(|(id, reason)| match SelectedBy::try_from(reason) {
+                Ok(reason) => Some((id, reason)),
+                Err(e) => {
+                    log::warn!("Ignoring pattern {}. Error: {}", &id, e);
+                    None
+                }
+            })
             .collect();
         Ok(patterns)
     }

rust/agama-server/src/software/web.rs

@@ -11,7 +11,7 @@ use agama_lib::{
     product::{Product, ProductClient},
     software::{
         proxies::{Software1Proxy, SoftwareProductProxy},
-        Pattern, SelectedBy, SoftwareClient,
+        Pattern, SelectedBy, SoftwareClient, UnknownSelectedBy,
     },
 };
 use axum::{
@@ -90,16 +90,34 @@ async fn patterns_changed_stream(
         .await
         .then(|change| async move {
             if let Ok(patterns) = change.get().await {
-                let patterns: HashMap<String, SelectedBy> =
-                    patterns.into_iter().map(|(k, v)| (k, v.into())).collect();
-                return Some(Event::PatternsChanged(patterns));
+                return match reason_to_selected_by(patterns) {
+                    Ok(patterns) => Some(patterns),
+                    Err(error) => {
+                        log::warn!("Ignoring the list of changed patterns. Error: {}", error);
+                        None
+                    }
+                };
             }
             None
         })
-        .filter_map(|e| e);
+        .filter_map(|e| e.map(Event::PatternsChanged));
     Ok(stream)
 }
 
+// Returns a hash replacing the selection "reason" from D-Bus with a SelectedBy variant.
+fn reason_to_selected_by(
+    patterns: HashMap<String, u8>,
+) -> Result<HashMap<String, SelectedBy>, UnknownSelectedBy> {
+    let mut selected: HashMap<String, SelectedBy> = HashMap::new();
+    for (id, reason) in patterns {
+        match SelectedBy::try_from(reason) {
+            Ok(selected_by) => selected.insert(id, selected_by),
+            Err(e) => return Err(e),
+        };
+    }
+    Ok(selected)
+}
+
 /// Sets up and returns the axum service for the software module.
 pub async fn software_service(dbus: zbus::Connection) -> Result<Router, ServiceError> {
     let product = ProductClient::new(dbus.clone()).await?;