Rename "channel" to "conversation" within the server.

I've split this from the schema and API changes because, frankly, it's huge. Annoyingly so. There are no semantic changes in this, it's all symbol changes, but there are a _lot_ of them because the term "channel" leaks all over everything in a service whose primary role is managing messages sent to channels (now, conversations).

I found a buggy test while working on this! It's not fixed in this commit, because it felt mean to hide a real change in the middle of this much chaff.

2 files changed, 245 insertions, 0 deletions

diff --git a/src/conversation/handlers/delete/mod.rs b/src/conversation/handlers/delete/mod.rs
new file mode 100644
index 0000000..272165a
--- /dev/null
+++ b/src/conversation/handlers/delete/mod.rs
@@ -0,0 +1,61 @@
+use axum::{
+    extract::{Json, Path, State},
+    http::StatusCode,
+    response::{self, IntoResponse},
+};
+
+use crate::{
+    app::App,
+    clock::RequestedAt,
+    conversation::{self, app, handlers::PathInfo},
+    error::{Internal, NotFound},
+    token::extract::Identity,
+};
+
+#[cfg(test)]
+mod test;
+
+pub async fn handler(
+    State(app): State<App>,
+    Path(conversation): Path<PathInfo>,
+    RequestedAt(deleted_at): RequestedAt,
+    _: Identity,
+) -> Result<Response, Error> {
+    app.conversations()
+        .delete(&conversation, &deleted_at)
+        .await?;
+
+    Ok(Response { id: conversation })
+}
+
+#[derive(Debug, serde::Serialize)]
+pub struct Response {
+    pub id: conversation::Id,
+}
+
+impl IntoResponse for Response {
+    fn into_response(self) -> response::Response {
+        (StatusCode::ACCEPTED, Json(self)).into_response()
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+#[error(transparent)]
+pub struct Error(#[from] pub app::DeleteError);
+
+impl IntoResponse for Error {
+    fn into_response(self) -> response::Response {
+        let Self(error) = self;
+        match error {
+            app::DeleteError::NotFound(_) | app::DeleteError::Deleted(_) => {
+                NotFound(error).into_response()
+            }
+            app::DeleteError::NotEmpty(_) => {
+                (StatusCode::CONFLICT, error.to_string()).into_response()
+            }
+            app::DeleteError::Name(_) | app::DeleteError::Database(_) => {
+                Internal::from(error).into_response()
+            }
+        }
+    }
+}
diff --git a/src/conversation/handlers/delete/test.rs b/src/conversation/handlers/delete/test.rs
new file mode 100644
index 0000000..2718d3b
--- /dev/null
+++ b/src/conversation/handlers/delete/test.rs
@@ -0,0 +1,184 @@
+use axum::extract::{Path, State};
+use itertools::Itertools;
+
+use crate::{conversation::app, test::fixtures};
+
+#[tokio::test]
+pub async fn valid_conversation() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+    let conversation = fixtures::conversation::create(&app, &fixtures::now()).await;
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let response = super::handler(
+        State(app.clone()),
+        Path(conversation.id.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect("deleting a valid conversation succeeds");
+
+    // Verify the response
+
+    assert_eq!(conversation.id, response.id);
+
+    // Verify the semantics
+
+    let snapshot = app.boot().snapshot().await.expect("boot always succeeds");
+    let created = snapshot
+        .events
+        .into_iter()
+        .filter_map(fixtures::event::conversation)
+        .filter_map(fixtures::event::conversation::created)
+        .exactly_one()
+        .expect("only one conversation has been created");
+    // We don't expect `conversation` to match the event exactly, as the name will have
+    // been tombstoned and the conversation given a `deleted_at` date.
+    assert_eq!(conversation.id, created.conversation.id);
+}
+
+#[tokio::test]
+pub async fn invalid_conversation_id() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let conversation = fixtures::conversation::fictitious();
+    let super::Error(error) = super::handler(
+        State(app.clone()),
+        Path(conversation.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect_err("deleting a nonexistent conversation fails");
+
+    // Verify the response
+
+    assert!(matches!(error, app::DeleteError::NotFound(id) if id == conversation));
+}
+
+#[tokio::test]
+pub async fn conversation_deleted() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+    let conversation = fixtures::conversation::create(&app, &fixtures::now()).await;
+
+    app.conversations()
+        .delete(&conversation.id, &fixtures::now())
+        .await
+        .expect("deleting a recently-created conversation succeeds");
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let super::Error(error) = super::handler(
+        State(app.clone()),
+        Path(conversation.id.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect_err("deleting a deleted conversation fails");
+
+    // Verify the response
+
+    assert!(matches!(error, app::DeleteError::Deleted(id) if id == conversation.id));
+}
+
+#[tokio::test]
+pub async fn conversation_expired() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+    let conversation = fixtures::conversation::create(&app, &fixtures::ancient()).await;
+
+    app.conversations()
+        .expire(&fixtures::now())
+        .await
+        .expect("expiring conversations always succeeds");
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let super::Error(error) = super::handler(
+        State(app.clone()),
+        Path(conversation.id.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect_err("deleting an expired conversation fails");
+
+    // Verify the response
+
+    assert!(matches!(error, app::DeleteError::Deleted(id) if id == conversation.id));
+}
+
+#[tokio::test]
+pub async fn conversation_purged() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+    let conversation = fixtures::conversation::create(&app, &fixtures::ancient()).await;
+
+    app.conversations()
+        .expire(&fixtures::old())
+        .await
+        .expect("expiring conversations always succeeds");
+
+    app.conversations()
+        .purge(&fixtures::now())
+        .await
+        .expect("purging conversations always succeeds");
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let super::Error(error) = super::handler(
+        State(app.clone()),
+        Path(conversation.id.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect_err("deleting a purged conversation fails");
+
+    // Verify the response
+
+    assert!(matches!(error, app::DeleteError::NotFound(id) if id == conversation.id));
+}
+
+#[tokio::test]
+pub async fn conversation_not_empty() {
+    // Set up the environment
+
+    let app = fixtures::scratch_app().await;
+    let conversation = fixtures::conversation::create(&app, &fixtures::now()).await;
+    let sender = fixtures::user::create(&app, &fixtures::now()).await;
+    fixtures::message::send(&app, &conversation, &sender, &fixtures::now()).await;
+
+    // Send the request
+
+    let deleter = fixtures::identity::create(&app, &fixtures::now()).await;
+    let super::Error(error) = super::handler(
+        State(app.clone()),
+        Path(conversation.id.clone()),
+        fixtures::now(),
+        deleter,
+    )
+    .await
+    .expect_err("deleting a conversation with messages fails");
+
+    // Verify the response
+
+    assert!(matches!(error, app::DeleteError::NotEmpty(id) if id == conversation.id));
+}