Add buffer integration test

Rearrange channel crate structure
Get channel buffer from database

co-authored-by: Max <max@zed.dev>

crates/collab/src/db/queries.rs

@@ -9,6 +9,3 @@ pub mod rooms;
 pub mod servers;
 pub mod signups;
 pub mod users;
-
-#[cfg(test)]
-pub mod buffer_tests;

crates/collab/src/db/queries/channels.rs

@@ -689,6 +689,34 @@ impl Database {
         })
         .await
     }
+
+    pub async fn get_or_create_buffer_for_channel(
+        &self,
+        channel_id: ChannelId,
+    ) -> Result<BufferId> {
+        self.transaction(|tx| async move {
+            let tx = tx;
+            let channel = channel::Entity::find_by_id(channel_id)
+                .one(&*tx)
+                .await?
+                .ok_or_else(|| anyhow!("invalid channel"))?;
+
+            if let Some(id) = channel.main_buffer_id {
+                return Ok(id);
+            } else {
+                let buffer = buffer::ActiveModel::new().insert(&*tx).await?;
+                channel::ActiveModel {
+                    id: ActiveValue::Unchanged(channel_id),
+                    main_buffer_id: ActiveValue::Set(Some(buffer.id)),
+                    ..Default::default()
+                }
+                .update(&*tx)
+                .await?;
+                Ok(buffer.id)
+            }
+        })
+        .await
+    }
 }
 
 #[derive(Copy, Clone, Debug, EnumIter, DeriveColumn)]

crates/collab/src/db/tables/channel.rs

@@ -1,4 +1,4 @@
-use crate::db::ChannelId;
+use crate::db::{BufferId, ChannelId};
 use sea_orm::entity::prelude::*;
 
 #[derive(Clone, Debug, Default, PartialEq, Eq, DeriveEntityModel)]
@@ -7,6 +7,7 @@ pub struct Model {
     #[sea_orm(primary_key)]
     pub id: ChannelId,
     pub name: String,
+    pub main_buffer_id: Option<BufferId>,
 }
 
 impl ActiveModelBehavior for ActiveModel {}

crates/collab/src/db/tests.rs

@@ -1,3 +1,6 @@
+mod buffer_tests;
+mod db_tests;
+
 use super::*;
 use gpui::executor::Background;
 use parking_lot::Mutex;
@@ -96,7 +99,7 @@ macro_rules! test_both_dbs {
     ($test_name:ident, $postgres_test_name:ident, $sqlite_test_name:ident) => {
         #[gpui::test]
         async fn $postgres_test_name() {
-            let test_db = crate::db::test_db::TestDb::postgres(
+            let test_db = crate::db::TestDb::postgres(
                 gpui::executor::Deterministic::new(0).build_background(),
             );
             $test_name(test_db.db()).await;
@@ -104,9 +107,8 @@ macro_rules! test_both_dbs {
 
         #[gpui::test]
         async fn $sqlite_test_name() {
-            let test_db = crate::db::test_db::TestDb::sqlite(
-                gpui::executor::Deterministic::new(0).build_background(),
-            );
+            let test_db =
+                crate::db::TestDb::sqlite(gpui::executor::Deterministic::new(0).build_background());
             $test_name(test_db.db()).await;
         }
     };

crates/collab/src/db/tests/db_tests.rs

@@ -3,7 +3,7 @@ use crate::test_both_dbs;
 use gpui::executor::{Background, Deterministic};
 use pretty_assertions::{assert_eq, assert_ne};
 use std::sync::Arc;
-use test_db::TestDb;
+use tests::TestDb;
 
 test_both_dbs!(
     test_get_users,
@@ -1329,6 +1329,35 @@ async fn test_channel_renames(db: &Arc<Database>) {
     assert!(bad_name_rename.is_err())
 }
 
+test_both_dbs!(
+    test_get_or_create_channel_buffer,
+    test_get_or_create_channel_buffer_postgres,
+    test_get_or_create_channel_buffer_sqlite
+);
+
+async fn test_get_or_create_channel_buffer(db: &Arc<Database>) {
+    let a_id = db
+        .create_user(
+            "user1@example.com",
+            false,
+            NewUserParams {
+                github_login: "user1".into(),
+                github_user_id: 5,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+
+    let zed_id = db.create_root_channel("zed", "1", a_id).await.unwrap();
+
+    let first_buffer_id = db.get_or_create_buffer_for_channel(zed_id).await.unwrap();
+    let second_buffer_id = db.get_or_create_buffer_for_channel(zed_id).await.unwrap();
+
+    assert_eq!(first_buffer_id, second_buffer_id);
+}
+
 #[gpui::test]
 async fn test_multiple_signup_overwrite() {
     let test_db = TestDb::postgres(build_background_executor());