App methods now return errors that allow not-found cases to be distinguished.

1 files changed, 31 insertions, 9 deletions

diff --git a/src/channel/app.rs b/src/channel/app.rs
index 29d9c09..e72564d 100644
--- a/src/channel/app.rs
+++ b/src/channel/app.rs
@@ -16,6 +16,7 @@ use crate::{
     error::BoxedError,
     repo::{
         channel::{self, Channel, Provider as _},
+        error::NotFound as _,
         login::Login,
     },
 };
@@ -30,7 +31,7 @@ impl<'a> Channels<'a> {
         Self { db, broadcaster }
     }
 
-    pub async fn create(&self, name: &str) -> Result<(), BoxedError> {
+    pub async fn create(&self, name: &str) -> Result<(), InternalError> {
         let mut tx = self.db.begin().await?;
         let channel = tx.channels().create(name).await?;
         self.broadcaster.register_channel(&channel);
@@ -39,7 +40,7 @@ impl<'a> Channels<'a> {
         Ok(())
     }
 
-    pub async fn all(&self) -> Result<Vec<Channel>, BoxedError> {
+    pub async fn all(&self) -> Result<Vec<Channel>, InternalError> {
         let mut tx = self.db.begin().await?;
         let channels = tx.channels().all().await?;
         tx.commit().await?;
@@ -53,9 +54,13 @@ impl<'a> Channels<'a> {
         channel: &channel::Id,
         body: &str,
         sent_at: &DateTime,
-    ) -> Result<(), BoxedError> {
+    ) -> Result<(), EventsError> {
         let mut tx = self.db.begin().await?;
-        let channel = tx.channels().by_id(channel).await?;
+        let channel = tx
+            .channels()
+            .by_id(channel)
+            .await
+            .not_found(|| EventsError::ChannelNotFound(channel.clone()))?;
         let message = tx
             .broadcast()
             .create(login, &channel, body, sent_at)
@@ -70,11 +75,8 @@ impl<'a> Channels<'a> {
         &self,
         channel: &channel::Id,
         resume_at: Option<&DateTime>,
-    ) -> Result<impl Stream<Item = Result<broadcast::Message, BoxedError>> + 'static, BoxedError>
+    ) -> Result<impl Stream<Item = Result<broadcast::Message, BoxedError>> + 'static, EventsError>
     {
-        let mut tx = self.db.begin().await?;
-        let channel = tx.channels().by_id(channel).await?;
-
         fn skip_stale<E>(
             resume_at: Option<&DateTime>,
         ) -> impl for<'m> FnMut(&'m broadcast::Message) -> future::Ready<Result<bool, E>> {
@@ -86,6 +88,12 @@ impl<'a> Channels<'a> {
                 }))
             }
         }
+        let mut tx = self
+            .db
+            .begin()
+            .await
+            .not_found(|| EventsError::ChannelNotFound(channel.clone()))?;
+        let channel = tx.channels().by_id(channel).await?;
 
         let live_messages = self
             .broadcaster
@@ -102,6 +110,20 @@ impl<'a> Channels<'a> {
     }
 }
 
+#[derive(Debug, thiserror::Error)]
+pub enum InternalError {
+    #[error("database error: {0}")]
+    DatabaseError(#[from] sqlx::Error),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum EventsError {
+    #[error("channel {0} not found")]
+    ChannelNotFound(channel::Id),
+    #[error("database error: {0}")]
+    DatabaseError(#[from] sqlx::Error),
+}
+
 // Clones will share the same senders collection.
 #[derive(Clone)]
 pub struct Broadcaster {
@@ -112,7 +134,7 @@ pub struct Broadcaster {
 }
 
 impl Broadcaster {
-    pub async fn from_database(db: &SqlitePool) -> Result<Self, BoxedError> {
+    pub async fn from_database(db: &SqlitePool) -> Result<Self, sqlx::Error> {
         let mut tx = db.begin().await?;
         let channels = tx.channels().all().await?;
         tx.commit().await?;