Remove the snapshot fields from `/api/boot`.

Clients now _must_ construct their state from the event stream; it is no longer possible for them to delegate that work to the server.

9 files changed, 41 insertions, 68 deletions

diff --git a/src/boot/app.rs b/src/boot/app.rs
index 690bcf4..89eec12 100644
--- a/src/boot/app.rs
+++ b/src/boot/app.rs
@@ -23,42 +23,27 @@ impl<'a> Boot<'a> {
         let mut tx = self.db.begin().await?;
         let resume_point = tx.sequence().current().await?;
 
-        let user_histories = tx.users().all(resume_point).await?;
-        let channel_histories = tx.channels().all(resume_point).await?;
-        let message_histories = tx.messages().all(resume_point).await?;
+        let users = tx.users().all(resume_point).await?;
+        let channels = tx.channels().all(resume_point).await?;
+        let messages = tx.messages().all(resume_point).await?;
 
         tx.commit().await?;
 
-        let users = user_histories
-            .iter()
-            .filter_map(|user| user.as_of(resume_point))
-            .collect();
-
-        let channels = channel_histories
-            .iter()
-            .filter_map(|channel| channel.as_of(resume_point))
-            .collect();
-
-        let messages = message_histories
-            .iter()
-            .filter_map(|message| message.as_of(resume_point))
-            .collect();
-
-        let user_events = user_histories
+        let user_events = users
             .iter()
             .map(user::History::events)
             .kmerge_by(Sequence::merge)
             .filter(Sequence::up_to(resume_point))
             .map(Event::from);
 
-        let channel_events = channel_histories
+        let channel_events = channels
             .iter()
             .map(channel::History::events)
             .kmerge_by(Sequence::merge)
             .filter(Sequence::up_to(resume_point))
             .map(Event::from);
 
-        let message_events = message_histories
+        let message_events = messages
             .iter()
             .map(message::History::events)
             .kmerge_by(Sequence::merge)
@@ -72,9 +57,6 @@ impl<'a> Boot<'a> {
 
         Ok(Snapshot {
             resume_point,
-            users,
-            channels,
-            messages,
             events,
         })
     }
diff --git a/src/boot/handlers/boot/test.rs b/src/boot/handlers/boot/test.rs
index d68618e..1e590a7 100644
--- a/src/boot/handlers/boot/test.rs
+++ b/src/boot/handlers/boot/test.rs
@@ -25,8 +25,6 @@ async fn includes_users() {
         .await
         .expect("boot always succeeds");
 
-    assert!(response.snapshot.users.contains(&spectator));
-
     let created = response
         .snapshot
         .events
@@ -48,8 +46,6 @@ async fn includes_channels() {
         .await
         .expect("boot always succeeds");
 
-    assert!(response.snapshot.channels.contains(&channel));
-
     let created = response
         .snapshot
         .events
@@ -73,8 +69,6 @@ async fn includes_messages() {
         .await
         .expect("boot always succeeds");
 
-    assert!(response.snapshot.messages.contains(&message));
-
     let sent = response
         .snapshot
         .events
@@ -87,7 +81,7 @@ async fn includes_messages() {
 }
 
 #[tokio::test]
-async fn excludes_expired_messages() {
+async fn includes_expired_messages() {
     let app = fixtures::scratch_app().await;
     let sender = fixtures::user::create(&app, &fixtures::ancient()).await;
     let channel = fixtures::channel::create(&app, &fixtures::ancient()).await;
@@ -104,8 +98,6 @@ async fn excludes_expired_messages() {
         .await
         .expect("boot always succeeds");
 
-    assert!(!response.snapshot.messages.contains(&expired_message));
-
     let sent = response
         .snapshot
         .events
@@ -131,7 +123,7 @@ async fn excludes_expired_messages() {
 }
 
 #[tokio::test]
-async fn excludes_deleted_messages() {
+async fn includes_deleted_messages() {
     let app = fixtures::scratch_app().await;
     let sender = fixtures::user::create(&app, &fixtures::now()).await;
     let channel = fixtures::channel::create(&app, &fixtures::now()).await;
@@ -147,8 +139,6 @@ async fn excludes_deleted_messages() {
         .await
         .expect("boot always succeeds");
 
-    assert!(!response.snapshot.messages.contains(&deleted_message));
-
     let sent = response
         .snapshot
         .events
@@ -174,7 +164,7 @@ async fn excludes_deleted_messages() {
 }
 
 #[tokio::test]
-async fn excludes_expired_channels() {
+async fn includes_expired_channels() {
     let app = fixtures::scratch_app().await;
     let expired_channel = fixtures::channel::create(&app, &fixtures::ancient()).await;
 
@@ -188,8 +178,6 @@ async fn excludes_expired_channels() {
         .await
         .expect("boot always succeeds");
 
-    assert!(!response.snapshot.channels.contains(&expired_channel));
-
     let created = response
         .snapshot
         .events
@@ -215,7 +203,7 @@ async fn excludes_expired_channels() {
 }
 
 #[tokio::test]
-async fn excludes_deleted_channels() {
+async fn includes_deleted_channels() {
     let app = fixtures::scratch_app().await;
     let deleted_channel = fixtures::channel::create(&app, &fixtures::now()).await;
 
@@ -229,8 +217,6 @@ async fn excludes_deleted_channels() {
         .await
         .expect("boot always succeeds");
 
-    assert!(!response.snapshot.channels.contains(&deleted_channel));
-
     let created = response
         .snapshot
         .events
diff --git a/src/boot/mod.rs b/src/boot/mod.rs
index 148e87d..e0d35d9 100644
--- a/src/boot/mod.rs
+++ b/src/boot/mod.rs
@@ -1,4 +1,4 @@
-use crate::{channel::Channel, event::Event, event::Sequence, message::Message, user::User};
+use crate::{event::Event, event::Sequence};
 
 pub mod app;
 pub mod handlers;
@@ -6,8 +6,5 @@ pub mod handlers;
 #[derive(serde::Serialize)]
 pub struct Snapshot {
     pub resume_point: Sequence,
-    pub users: Vec<User>,
-    pub channels: Vec<Channel>,
-    pub messages: Vec<Message>,
     pub events: Vec<Event>,
 }
diff --git a/src/channel/handlers/create/test.rs b/src/channel/handlers/create/test.rs
index 595a879..31bb778 100644
--- a/src/channel/handlers/create/test.rs
+++ b/src/channel/handlers/create/test.rs
@@ -2,6 +2,7 @@ use std::future;
 
 use axum::extract::{Json, State};
 use futures::stream::StreamExt as _;
+use itertools::Itertools;
 
 use crate::{
     channel::app,
@@ -33,7 +34,14 @@ async fn new_channel() {
     // Verify the semantics
 
     let snapshot = app.boot().snapshot().await.expect("boot always succeeds");
-    assert!(snapshot.channels.iter().any(|channel| channel == &response));
+    let created = snapshot
+        .events
+        .into_iter()
+        .filter_map(fixtures::event::channel)
+        .filter_map(fixtures::event::channel::created)
+        .exactly_one()
+        .expect("only one channel has been created");
+    assert_eq!(response, created.channel);
 
     let channel = app
         .channels()
diff --git a/src/channel/handlers/delete/test.rs b/src/channel/handlers/delete/test.rs
index b1e42ea..99c19db 100644
--- a/src/channel/handlers/delete/test.rs
+++ b/src/channel/handlers/delete/test.rs
@@ -1,4 +1,5 @@
 use axum::extract::{Path, State};
+use itertools::Itertools;
 
 use crate::{channel::app, test::fixtures};
 
@@ -28,7 +29,16 @@ pub async fn valid_channel() {
     // Verify the semantics
 
     let snapshot = app.boot().snapshot().await.expect("boot always succeeds");
-    assert!(!snapshot.channels.contains(&channel));
+    let created = snapshot
+        .events
+        .into_iter()
+        .filter_map(fixtures::event::channel)
+        .filter_map(fixtures::event::channel::created)
+        .exactly_one()
+        .expect("only one channel has been created");
+    // We don't expect `channel` to match the event exactly, as the name will have been
+    // tombstoned and the channel given a `deleted_at` date.
+    assert_eq!(channel.id, created.channel.id);
 }
 
 #[tokio::test]
diff --git a/src/channel/history.rs b/src/channel/history.rs
index faf6a0e..7f18e45 100644
--- a/src/channel/history.rs
+++ b/src/channel/history.rs
@@ -27,12 +27,6 @@ impl History {
         self.channel.clone()
     }
 
-    pub fn as_of(&self, resume_point: Sequence) -> Option<Channel> {
-        self.events()
-            .filter(Sequence::up_to(resume_point))
-            .collect()
-    }
-
     // Snapshot of this channel as of all events recorded in this history.
     pub fn as_snapshot(&self) -> Option<Channel> {
         self.events().collect()
diff --git a/src/message/handlers/delete/test.rs b/src/message/handlers/delete/test.rs
index 15aa2c2..f567eb7 100644
--- a/src/message/handlers/delete/test.rs
+++ b/src/message/handlers/delete/test.rs
@@ -1,4 +1,5 @@
 use axum::extract::{Path, State};
+use itertools::Itertools;
 
 use crate::{message::app, test::fixtures};
 
@@ -29,7 +30,14 @@ pub async fn delete_message() {
     // Verify the semantics
 
     let snapshot = app.boot().snapshot().await.expect("boot always succeeds");
-    assert!(!snapshot.messages.contains(&message));
+    let deleted = snapshot
+        .events
+        .into_iter()
+        .filter_map(fixtures::event::message)
+        .filter_map(fixtures::event::message::deleted)
+        .exactly_one()
+        .expect("only one message has been deleted");
+    assert_eq!(response.id, deleted.id)
 }
 
 #[tokio::test]
diff --git a/src/message/history.rs b/src/message/history.rs
index 1a72c08..7585e1c 100644
--- a/src/message/history.rs
+++ b/src/message/history.rs
@@ -27,12 +27,6 @@ impl History {
         self.message.clone()
     }
 
-    pub fn as_of(&self, resume_point: Sequence) -> Option<Message> {
-        self.events()
-            .filter(Sequence::up_to(resume_point))
-            .collect()
-    }
-
     // Snapshot of this message as of all events recorded in this history.
     pub fn as_snapshot(&self) -> Option<Message> {
         self.events().collect()
diff --git a/src/user/history.rs b/src/user/history.rs
index ae7a561..72e0aee 100644
--- a/src/user/history.rs
+++ b/src/user/history.rs
@@ -2,7 +2,7 @@ use super::{
     Id, User,
     event::{Created, Event},
 };
-use crate::event::{Instant, Sequence};
+use crate::event::Instant;
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct History {
@@ -24,12 +24,6 @@ impl History {
         self.user.clone()
     }
 
-    pub fn as_of(&self, resume_point: Sequence) -> Option<User> {
-        self.events()
-            .filter(Sequence::up_to(resume_point))
-            .collect()
-    }
-
     // Snapshot of this user, as of all events recorded in this history.
     pub fn as_snapshot(&self) -> Option<User> {
         self.events().collect()