Add buffer integration test

Rearrange channel crate structure
Get channel buffer from database

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

crates/channel/Cargo.toml

@@ -0,0 +1,51 @@
+[package]
+name = "channel"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[lib]
+path = "src/channel.rs"
+doctest = false
+
+[features]
+test-support = ["collections/test-support", "gpui/test-support", "rpc/test-support"]
+
+[dependencies]
+client = { path = "../client" }
+collections = { path = "../collections" }
+db = { path = "../db" }
+gpui = { path = "../gpui" }
+util = { path = "../util" }
+rpc = { path = "../rpc" }
+text = { path = "../text" }
+language = { path = "../language" }
+settings = { path = "../settings" }
+staff_mode = { path = "../staff_mode" }
+sum_tree = { path = "../sum_tree" }
+
+anyhow.workspace = true
+futures.workspace = true
+image = "0.23"
+lazy_static.workspace = true
+log.workspace = true
+parking_lot.workspace = true
+postage.workspace = true
+rand.workspace = true
+schemars.workspace = true
+smol.workspace = true
+thiserror.workspace = true
+time.workspace = true
+tiny_http = "0.8"
+uuid = { version = "1.1.2", features = ["v4"] }
+url = "2.2"
+serde.workspace = true
+serde_derive.workspace = true
+tempfile = "3"
+
+[dev-dependencies]
+collections = { path = "../collections", features = ["test-support"] }
+gpui = { path = "../gpui", features = ["test-support"] }
+rpc = { path = "../rpc", features = ["test-support"] }
+settings = { path = "../settings", features = ["test-support"] }
+util = { path = "../util", features = ["test-support"] }

crates/channel/src/channel.rs

@@ -0,0 +1,7 @@
+mod channel_store;
+
+pub mod channel_buffer;
+pub use channel_store::*;
+
+#[cfg(test)]
+mod channel_store_tests;

crates/channel/src/channel_buffer.rs

@@ -0,0 +1,80 @@
+use crate::ChannelId;
+use anyhow::Result;
+use client::Client;
+use gpui::{Entity, ModelContext, ModelHandle, Task};
+use rpc::proto::GetChannelBuffer;
+use std::sync::Arc;
+
+// Open the channel document
+// ChannelDocumentView { ChannelDocument, Editor } -> On clone, clones internal ChannelDocument handle, instantiates new editor
+// Produces a view which is: (ChannelDocument, Editor), ChannelDocument manages subscriptions
+// ChannelDocuments -> Buffers -> Editor with that buffer
+
+// ChannelDocuments {
+//     ChannleBuffers: HashMap<bufferId, ModelHandle<language::Buffer>>
+// }
+
+pub struct ChannelBuffer {
+    channel_id: ChannelId,
+    buffer: Option<ModelHandle<language::Buffer>>,
+    client: Arc<Client>,
+}
+
+impl Entity for ChannelBuffer {
+    type Event = ();
+}
+
+impl ChannelBuffer {
+    pub fn for_channel(
+        channel_id: ChannelId,
+        client: Arc<Client>,
+        cx: &mut ModelContext<Self>,
+    ) -> Self {
+        Self {
+            channel_id,
+            client,
+            buffer: None,
+        }
+    }
+
+    fn on_buffer_update(
+        &mut self,
+        buffer: ModelHandle<language::Buffer>,
+        event: &language::Event,
+        cx: &mut ModelContext<Self>,
+    ) {
+        //
+    }
+
+    pub fn buffer(
+        &mut self,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<ModelHandle<language::Buffer>>> {
+        if let Some(buffer) = &self.buffer {
+            Task::ready(Ok(buffer.clone()))
+        } else {
+            let channel_id = self.channel_id;
+            let client = self.client.clone();
+            cx.spawn(|this, mut cx| async move {
+                let response = client.request(GetChannelBuffer { channel_id }).await?;
+
+                let base_text = response.base_text;
+                let operations = response
+                    .operations
+                    .into_iter()
+                    .map(language::proto::deserialize_operation)
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                this.update(&mut cx, |this, cx| {
+                    let buffer = cx.add_model(|cx| language::Buffer::new(0, base_text, cx));
+                    buffer.update(cx, |buffer, cx| buffer.apply_ops(operations, cx))?;
+
+                    cx.subscribe(&buffer, Self::on_buffer_update).detach();
+
+                    this.buffer = Some(buffer.clone());
+                    anyhow::Ok(buffer)
+                })
+            })
+        }
+    }
+}

crates/channel/src/channel_store.rs

@@ -0,0 +1,560 @@
+use anyhow::anyhow;
+use anyhow::Result;
+use client::Status;
+use client::UserId;
+use client::{Client, Subscription, User, UserStore};
+use collections::HashMap;
+use collections::HashSet;
+use futures::channel::mpsc;
+use futures::Future;
+use futures::StreamExt;
+use gpui::{AsyncAppContext, Entity, ModelContext, ModelHandle, Task};
+use rpc::{proto, TypedEnvelope};
+use std::sync::Arc;
+use util::ResultExt;
+
+pub type ChannelId = u64;
+
+pub struct ChannelStore {
+    channels_by_id: HashMap<ChannelId, Arc<Channel>>,
+    channel_paths: Vec<Vec<ChannelId>>,
+    channel_invitations: Vec<Arc<Channel>>,
+    channel_participants: HashMap<ChannelId, Vec<Arc<User>>>,
+    channels_with_admin_privileges: HashSet<ChannelId>,
+    outgoing_invites: HashSet<(ChannelId, UserId)>,
+    update_channels_tx: mpsc::UnboundedSender<proto::UpdateChannels>,
+    client: Arc<Client>,
+    user_store: ModelHandle<UserStore>,
+    _rpc_subscription: Subscription,
+    _watch_connection_status: Task<()>,
+    _update_channels: Task<()>,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Channel {
+    pub id: ChannelId,
+    pub name: String,
+}
+
+pub struct ChannelMembership {
+    pub user: Arc<User>,
+    pub kind: proto::channel_member::Kind,
+    pub admin: bool,
+}
+
+pub enum ChannelEvent {
+    ChannelCreated(ChannelId),
+    ChannelRenamed(ChannelId),
+}
+
+impl Entity for ChannelStore {
+    type Event = ChannelEvent;
+}
+
+pub enum ChannelMemberStatus {
+    Invited,
+    Member,
+    NotMember,
+}
+
+impl ChannelStore {
+    pub fn new(
+        client: Arc<Client>,
+        user_store: ModelHandle<UserStore>,
+        cx: &mut ModelContext<Self>,
+    ) -> Self {
+        let rpc_subscription =
+            client.add_message_handler(cx.handle(), Self::handle_update_channels);
+
+        let (update_channels_tx, mut update_channels_rx) = mpsc::unbounded();
+        let mut connection_status = client.status();
+        let watch_connection_status = cx.spawn_weak(|this, mut cx| async move {
+            while let Some(status) = connection_status.next().await {
+                if matches!(status, Status::ConnectionLost | Status::SignedOut) {
+                    if let Some(this) = this.upgrade(&cx) {
+                        this.update(&mut cx, |this, cx| {
+                            this.channels_by_id.clear();
+                            this.channel_invitations.clear();
+                            this.channel_participants.clear();
+                            this.channels_with_admin_privileges.clear();
+                            this.channel_paths.clear();
+                            this.outgoing_invites.clear();
+                            cx.notify();
+                        });
+                    } else {
+                        break;
+                    }
+                }
+            }
+        });
+        Self {
+            channels_by_id: HashMap::default(),
+            channel_invitations: Vec::default(),
+            channel_paths: Vec::default(),
+            channel_participants: Default::default(),
+            channels_with_admin_privileges: Default::default(),
+            outgoing_invites: Default::default(),
+            update_channels_tx,
+            client,
+            user_store,
+            _rpc_subscription: rpc_subscription,
+            _watch_connection_status: watch_connection_status,
+            _update_channels: cx.spawn_weak(|this, mut cx| async move {
+                while let Some(update_channels) = update_channels_rx.next().await {
+                    if let Some(this) = this.upgrade(&cx) {
+                        let update_task = this.update(&mut cx, |this, cx| {
+                            this.update_channels(update_channels, cx)
+                        });
+                        if let Some(update_task) = update_task {
+                            update_task.await.log_err();
+                        }
+                    }
+                }
+            }),
+        }
+    }
+
+    pub fn has_children(&self, channel_id: ChannelId) -> bool {
+        self.channel_paths.iter().any(|path| {
+            if let Some(ix) = path.iter().position(|id| *id == channel_id) {
+                path.len() > ix + 1
+            } else {
+                false
+            }
+        })
+    }
+
+    pub fn channel_count(&self) -> usize {
+        self.channel_paths.len()
+    }
+
+    pub fn channels(&self) -> impl '_ + Iterator<Item = (usize, &Arc<Channel>)> {
+        self.channel_paths.iter().map(move |path| {
+            let id = path.last().unwrap();
+            let channel = self.channel_for_id(*id).unwrap();
+            (path.len() - 1, channel)
+        })
+    }
+
+    pub fn channel_at_index(&self, ix: usize) -> Option<(usize, &Arc<Channel>)> {
+        let path = self.channel_paths.get(ix)?;
+        let id = path.last().unwrap();
+        let channel = self.channel_for_id(*id).unwrap();
+        Some((path.len() - 1, channel))
+    }
+
+    pub fn channel_invitations(&self) -> &[Arc<Channel>] {
+        &self.channel_invitations
+    }
+
+    pub fn channel_for_id(&self, channel_id: ChannelId) -> Option<&Arc<Channel>> {
+        self.channels_by_id.get(&channel_id)
+    }
+
+    pub fn is_user_admin(&self, channel_id: ChannelId) -> bool {
+        self.channel_paths.iter().any(|path| {
+            if let Some(ix) = path.iter().position(|id| *id == channel_id) {
+                path[..=ix]
+                    .iter()
+                    .any(|id| self.channels_with_admin_privileges.contains(id))
+            } else {
+                false
+            }
+        })
+    }
+
+    pub fn channel_participants(&self, channel_id: ChannelId) -> &[Arc<User>] {
+        self.channel_participants
+            .get(&channel_id)
+            .map_or(&[], |v| v.as_slice())
+    }
+
+    pub fn create_channel(
+        &self,
+        name: &str,
+        parent_id: Option<ChannelId>,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<ChannelId>> {
+        let client = self.client.clone();
+        let name = name.trim_start_matches("#").to_owned();
+        cx.spawn(|this, mut cx| async move {
+            let channel = client
+                .request(proto::CreateChannel { name, parent_id })
+                .await?
+                .channel
+                .ok_or_else(|| anyhow!("missing channel in response"))?;
+
+            let channel_id = channel.id;
+
+            this.update(&mut cx, |this, cx| {
+                let task = this.update_channels(
+                    proto::UpdateChannels {
+                        channels: vec![channel],
+                        ..Default::default()
+                    },
+                    cx,
+                );
+                assert!(task.is_none());
+
+                // This event is emitted because the collab panel wants to clear the pending edit state
+                // before this frame is rendered. But we can't guarantee that the collab panel's future
+                // will resolve before this flush_effects finishes. Synchronously emitting this event
+                // ensures that the collab panel will observe this creation before the frame completes
+                cx.emit(ChannelEvent::ChannelCreated(channel_id));
+            });
+
+            Ok(channel_id)
+        })
+    }
+
+    pub fn invite_member(
+        &mut self,
+        channel_id: ChannelId,
+        user_id: UserId,
+        admin: bool,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<()>> {
+        if !self.outgoing_invites.insert((channel_id, user_id)) {
+            return Task::ready(Err(anyhow!("invite request already in progress")));
+        }
+
+        cx.notify();
+        let client = self.client.clone();
+        cx.spawn(|this, mut cx| async move {
+            let result = client
+                .request(proto::InviteChannelMember {
+                    channel_id,
+                    user_id,
+                    admin,
+                })
+                .await;
+
+            this.update(&mut cx, |this, cx| {
+                this.outgoing_invites.remove(&(channel_id, user_id));
+                cx.notify();
+            });
+
+            result?;
+
+            Ok(())
+        })
+    }
+
+    pub fn remove_member(
+        &mut self,
+        channel_id: ChannelId,
+        user_id: u64,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<()>> {
+        if !self.outgoing_invites.insert((channel_id, user_id)) {
+            return Task::ready(Err(anyhow!("invite request already in progress")));
+        }
+
+        cx.notify();
+        let client = self.client.clone();
+        cx.spawn(|this, mut cx| async move {
+            let result = client
+                .request(proto::RemoveChannelMember {
+                    channel_id,
+                    user_id,
+                })
+                .await;
+
+            this.update(&mut cx, |this, cx| {
+                this.outgoing_invites.remove(&(channel_id, user_id));
+                cx.notify();
+            });
+            result?;
+            Ok(())
+        })
+    }
+
+    pub fn set_member_admin(
+        &mut self,
+        channel_id: ChannelId,
+        user_id: UserId,
+        admin: bool,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<()>> {
+        if !self.outgoing_invites.insert((channel_id, user_id)) {
+            return Task::ready(Err(anyhow!("member request already in progress")));
+        }
+
+        cx.notify();
+        let client = self.client.clone();
+        cx.spawn(|this, mut cx| async move {
+            let result = client
+                .request(proto::SetChannelMemberAdmin {
+                    channel_id,
+                    user_id,
+                    admin,
+                })
+                .await;
+
+            this.update(&mut cx, |this, cx| {
+                this.outgoing_invites.remove(&(channel_id, user_id));
+                cx.notify();
+            });
+
+            result?;
+            Ok(())
+        })
+    }
+
+    pub fn rename(
+        &mut self,
+        channel_id: ChannelId,
+        new_name: &str,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<()>> {
+        let client = self.client.clone();
+        let name = new_name.to_string();
+        cx.spawn(|this, mut cx| async move {
+            let channel = client
+                .request(proto::RenameChannel { channel_id, name })
+                .await?
+                .channel
+                .ok_or_else(|| anyhow!("missing channel in response"))?;
+            this.update(&mut cx, |this, cx| {
+                let task = this.update_channels(
+                    proto::UpdateChannels {
+                        channels: vec![channel],
+                        ..Default::default()
+                    },
+                    cx,
+                );
+                assert!(task.is_none());
+
+                // This event is emitted because the collab panel wants to clear the pending edit state
+                // before this frame is rendered. But we can't guarantee that the collab panel's future
+                // will resolve before this flush_effects finishes. Synchronously emitting this event
+                // ensures that the collab panel will observe this creation before the frame complete
+                cx.emit(ChannelEvent::ChannelRenamed(channel_id))
+            });
+            Ok(())
+        })
+    }
+
+    pub fn respond_to_channel_invite(
+        &mut self,
+        channel_id: ChannelId,
+        accept: bool,
+    ) -> impl Future<Output = Result<()>> {
+        let client = self.client.clone();
+        async move {
+            client
+                .request(proto::RespondToChannelInvite { channel_id, accept })
+                .await?;
+            Ok(())
+        }
+    }
+
+    pub fn get_channel_member_details(
+        &self,
+        channel_id: ChannelId,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<Vec<ChannelMembership>>> {
+        let client = self.client.clone();
+        let user_store = self.user_store.downgrade();
+        cx.spawn(|_, mut cx| async move {
+            let response = client
+                .request(proto::GetChannelMembers { channel_id })
+                .await?;
+
+            let user_ids = response.members.iter().map(|m| m.user_id).collect();
+            let user_store = user_store
+                .upgrade(&cx)
+                .ok_or_else(|| anyhow!("user store dropped"))?;
+            let users = user_store
+                .update(&mut cx, |user_store, cx| user_store.get_users(user_ids, cx))
+                .await?;
+
+            Ok(users
+                .into_iter()
+                .zip(response.members)
+                .filter_map(|(user, member)| {
+                    Some(ChannelMembership {
+                        user,
+                        admin: member.admin,
+                        kind: proto::channel_member::Kind::from_i32(member.kind)?,
+                    })
+                })
+                .collect())
+        })
+    }
+
+    pub fn remove_channel(&self, channel_id: ChannelId) -> impl Future<Output = Result<()>> {
+        let client = self.client.clone();
+        async move {
+            client.request(proto::RemoveChannel { channel_id }).await?;
+            Ok(())
+        }
+    }
+
+    pub fn has_pending_channel_invite_response(&self, _: &Arc<Channel>) -> bool {
+        false
+    }
+
+    pub fn has_pending_channel_invite(&self, channel_id: ChannelId, user_id: UserId) -> bool {
+        self.outgoing_invites.contains(&(channel_id, user_id))
+    }
+
+    async fn handle_update_channels(
+        this: ModelHandle<Self>,
+        message: TypedEnvelope<proto::UpdateChannels>,
+        _: Arc<Client>,
+        mut cx: AsyncAppContext,
+    ) -> Result<()> {
+        this.update(&mut cx, |this, _| {
+            this.update_channels_tx
+                .unbounded_send(message.payload)
+                .unwrap();
+        });
+        Ok(())
+    }
+
+    pub(crate) fn update_channels(
+        &mut self,
+        payload: proto::UpdateChannels,
+        cx: &mut ModelContext<ChannelStore>,
+    ) -> Option<Task<Result<()>>> {
+        if !payload.remove_channel_invitations.is_empty() {
+            self.channel_invitations
+                .retain(|channel| !payload.remove_channel_invitations.contains(&channel.id));
+        }
+        for channel in payload.channel_invitations {
+            match self
+                .channel_invitations
+                .binary_search_by_key(&channel.id, |c| c.id)
+            {
+                Ok(ix) => Arc::make_mut(&mut self.channel_invitations[ix]).name = channel.name,
+                Err(ix) => self.channel_invitations.insert(
+                    ix,
+                    Arc::new(Channel {
+                        id: channel.id,
+                        name: channel.name,
+                    }),
+                ),
+            }
+        }
+
+        let channels_changed = !payload.channels.is_empty() || !payload.remove_channels.is_empty();
+        if channels_changed {
+            if !payload.remove_channels.is_empty() {
+                self.channels_by_id
+                    .retain(|channel_id, _| !payload.remove_channels.contains(channel_id));
+                self.channel_participants
+                    .retain(|channel_id, _| !payload.remove_channels.contains(channel_id));
+                self.channels_with_admin_privileges
+                    .retain(|channel_id| !payload.remove_channels.contains(channel_id));
+            }
+
+            for channel in payload.channels {
+                if let Some(existing_channel) = self.channels_by_id.get_mut(&channel.id) {
+                    // FIXME: We may be missing a path for this existing channel in certain cases
+                    let existing_channel = Arc::make_mut(existing_channel);
+                    existing_channel.name = channel.name;
+                    continue;
+                }
+
+                self.channels_by_id.insert(
+                    channel.id,
+                    Arc::new(Channel {
+                        id: channel.id,
+                        name: channel.name,
+                    }),
+                );
+
+                if let Some(parent_id) = channel.parent_id {
+                    let mut ix = 0;
+                    while ix < self.channel_paths.len() {
+                        let path = &self.channel_paths[ix];
+                        if path.ends_with(&[parent_id]) {
+                            let mut new_path = path.clone();
+                            new_path.push(channel.id);
+                            self.channel_paths.insert(ix + 1, new_path);
+                            ix += 1;
+                        }
+                        ix += 1;
+                    }
+                } else {
+                    self.channel_paths.push(vec![channel.id]);
+                }
+            }
+
+            self.channel_paths.sort_by(|a, b| {
+                let a = Self::channel_path_sorting_key(a, &self.channels_by_id);
+                let b = Self::channel_path_sorting_key(b, &self.channels_by_id);
+                a.cmp(b)
+            });
+            self.channel_paths.dedup();
+            self.channel_paths.retain(|path| {
+                path.iter()
+                    .all(|channel_id| self.channels_by_id.contains_key(channel_id))
+            });
+        }
+
+        for permission in payload.channel_permissions {
+            if permission.is_admin {
+                self.channels_with_admin_privileges
+                    .insert(permission.channel_id);
+            } else {
+                self.channels_with_admin_privileges
+                    .remove(&permission.channel_id);
+            }
+        }
+
+        cx.notify();
+        if payload.channel_participants.is_empty() {
+            return None;
+        }
+
+        let mut all_user_ids = Vec::new();
+        let channel_participants = payload.channel_participants;
+        for entry in &channel_participants {
+            for user_id in entry.participant_user_ids.iter() {
+                if let Err(ix) = all_user_ids.binary_search(user_id) {
+                    all_user_ids.insert(ix, *user_id);
+                }
+            }
+        }
+
+        let users = self
+            .user_store
+            .update(cx, |user_store, cx| user_store.get_users(all_user_ids, cx));
+        Some(cx.spawn(|this, mut cx| async move {
+            let users = users.await?;
+
+            this.update(&mut cx, |this, cx| {
+                for entry in &channel_participants {
+                    let mut participants: Vec<_> = entry
+                        .participant_user_ids
+                        .iter()
+                        .filter_map(|user_id| {
+                            users
+                                .binary_search_by_key(&user_id, |user| &user.id)
+                                .ok()
+                                .map(|ix| users[ix].clone())
+                        })
+                        .collect();
+
+                    participants.sort_by_key(|u| u.id);
+
+                    this.channel_participants
+                        .insert(entry.channel_id, participants);
+                }
+
+                cx.notify();
+            });
+            anyhow::Ok(())
+        }))
+    }
+
+    fn channel_path_sorting_key<'a>(
+        path: &'a [ChannelId],
+        channels_by_id: &'a HashMap<ChannelId, Arc<Channel>>,
+    ) -> impl 'a + Iterator<Item = Option<&'a str>> {
+        path.iter()
+            .map(|id| Some(channels_by_id.get(id)?.name.as_str()))
+    }
+}

crates/channel/src/channel_store_tests.rs

@@ -0,0 +1,168 @@
+use super::*;
+use client::{Client, UserStore};
+use gpui::{AppContext, ModelHandle};
+use rpc::proto;
+use util::http::FakeHttpClient;
+
+#[gpui::test]
+fn test_update_channels(cx: &mut AppContext) {
+    let http = FakeHttpClient::with_404_response();
+    let client = Client::new(http.clone(), cx);
+    let user_store = cx.add_model(|cx| UserStore::new(client.clone(), http, cx));
+
+    let channel_store = cx.add_model(|cx| ChannelStore::new(client, user_store, cx));
+
+    update_channels(
+        &channel_store,
+        proto::UpdateChannels {
+            channels: vec![
+                proto::Channel {
+                    id: 1,
+                    name: "b".to_string(),
+                    parent_id: None,
+                },
+                proto::Channel {
+                    id: 2,
+                    name: "a".to_string(),
+                    parent_id: None,
+                },
+            ],
+            channel_permissions: vec![proto::ChannelPermission {
+                channel_id: 1,
+                is_admin: true,
+            }],
+            ..Default::default()
+        },
+        cx,
+    );
+    assert_channels(
+        &channel_store,
+        &[
+            //
+            (0, "a".to_string(), false),
+            (0, "b".to_string(), true),
+        ],
+        cx,
+    );
+
+    update_channels(
+        &channel_store,
+        proto::UpdateChannels {
+            channels: vec![
+                proto::Channel {
+                    id: 3,
+                    name: "x".to_string(),
+                    parent_id: Some(1),
+                },
+                proto::Channel {
+                    id: 4,
+                    name: "y".to_string(),
+                    parent_id: Some(2),
+                },
+            ],
+            ..Default::default()
+        },
+        cx,
+    );
+    assert_channels(
+        &channel_store,
+        &[
+            (0, "a".to_string(), false),
+            (1, "y".to_string(), false),
+            (0, "b".to_string(), true),
+            (1, "x".to_string(), true),
+        ],
+        cx,
+    );
+}
+
+#[gpui::test]
+fn test_dangling_channel_paths(cx: &mut AppContext) {
+    let http = FakeHttpClient::with_404_response();
+    let client = Client::new(http.clone(), cx);
+    let user_store = cx.add_model(|cx| UserStore::new(client.clone(), http, cx));
+
+    let channel_store = cx.add_model(|cx| ChannelStore::new(client, user_store, cx));
+
+    update_channels(
+        &channel_store,
+        proto::UpdateChannels {
+            channels: vec![
+                proto::Channel {
+                    id: 0,
+                    name: "a".to_string(),
+                    parent_id: None,
+                },
+                proto::Channel {
+                    id: 1,
+                    name: "b".to_string(),
+                    parent_id: Some(0),
+                },
+                proto::Channel {
+                    id: 2,
+                    name: "c".to_string(),
+                    parent_id: Some(1),
+                },
+            ],
+            channel_permissions: vec![proto::ChannelPermission {
+                channel_id: 0,
+                is_admin: true,
+            }],
+            ..Default::default()
+        },
+        cx,
+    );
+    // Sanity check
+    assert_channels(
+        &channel_store,
+        &[
+            //
+            (0, "a".to_string(), true),
+            (1, "b".to_string(), true),
+            (2, "c".to_string(), true),
+        ],
+        cx,
+    );
+
+    update_channels(
+        &channel_store,
+        proto::UpdateChannels {
+            remove_channels: vec![1, 2],
+            ..Default::default()
+        },
+        cx,
+    );
+
+    // Make sure that the 1/2/3 path is gone
+    assert_channels(&channel_store, &[(0, "a".to_string(), true)], cx);
+}
+
+fn update_channels(
+    channel_store: &ModelHandle<ChannelStore>,
+    message: proto::UpdateChannels,
+    cx: &mut AppContext,
+) {
+    let task = channel_store.update(cx, |store, cx| store.update_channels(message, cx));
+    assert!(task.is_none());
+}
+
+#[track_caller]
+fn assert_channels(
+    channel_store: &ModelHandle<ChannelStore>,
+    expected_channels: &[(usize, String, bool)],
+    cx: &AppContext,
+) {
+    let actual = channel_store.read_with(cx, |store, _| {
+        store
+            .channels()
+            .map(|(depth, channel)| {
+                (
+                    depth,
+                    channel.name.to_string(),
+                    store.is_user_admin(channel.id),
+                )
+            })
+            .collect::<Vec<_>>()
+    });
+    assert_eq!(actual, expected_channels);
+}