use/enable let_underscore_must_use lint

Signed-off-by: strawberry <strawberry@puppygock.gay>

Cargo.toml

@@ -750,6 +750,7 @@ manual_let_else = "warn"
 trivially_copy_pass_by_ref = "warn"
 wildcard_imports = "warn"
 checked_conversions = "warn"
+let_underscore_must_use = "warn"
 #integer_arithmetic = "warn"
 #as_conversions = "warn"
 
@@ -767,7 +768,6 @@ mod_module_files = "allow"
 unwrap_used = "allow"
 expect_used = "allow"
 if_then_some_else_none = "allow"
-let_underscore_must_use = "allow"
 let_underscore_future = "allow"
 map_err_ignore = "allow"
 missing_docs_in_private_items = "allow"

src/admin/federation/federation_commands.rs

@@ -1,4 +1,4 @@
-use std::fmt::Write as _;
+use std::fmt::Write;
 
 use ruma::{events::room::message::RoomMessageEventContent, OwnedRoomId, RoomId, ServerName, UserId};
 
@@ -20,7 +20,8 @@ pub(crate) async fn incoming_federeation(_body: Vec<&str>) -> Result<RoomMessage
 
 	for (r, (e, i)) in map.iter() {
 		let elapsed = i.elapsed();
-		let _ = writeln!(msg, "{} {}: {}m{}s", r, e, elapsed.as_secs() / 60, elapsed.as_secs() % 60);
+		writeln!(msg, "{} {}: {}m{}s", r, e, elapsed.as_secs() / 60, elapsed.as_secs() % 60,)
+			.expect("should be able to write to string buffer");
 	}
 	Ok(RoomMessageEventContent::text_plain(&msg))
 }
@@ -120,7 +121,7 @@ pub(crate) async fn remote_user_in_rooms(_body: Vec<&str>, user_id: Box<UserId>)
 					members,
 					escape_html(name)
 				)
-				.unwrap();
+				.expect("should be able to write to string buffer");
 				output
 			})
 	);

src/admin/room/room_alias_commands.rs

@@ -1,4 +1,4 @@
-use std::fmt::Write as _;
+use std::fmt::Write;
 
 use ruma::{events::room::message::RoomMessageEventContent, RoomAliasId};
 
@@ -79,12 +79,13 @@ pub(crate) async fn process(command: RoomAliasCommand, _body: Vec<&str>) -> Resu
 				match aliases {
 					Ok(aliases) => {
 						let plain_list = aliases.iter().fold(String::new(), |mut output, alias| {
-							writeln!(output, "- {alias}").unwrap();
+							writeln!(output, "- {alias}").expect("should be able to write to string buffer");
 							output
 						});
 
 						let html_list = aliases.iter().fold(String::new(), |mut output, alias| {
-							writeln!(output, "<li>{}</li>", escape_html(alias.as_ref())).unwrap();
+							writeln!(output, "<li>{}</li>", escape_html(alias.as_ref()))
+								.expect("should be able to write to string buffer");
 							output
 						});
 
@@ -106,7 +107,8 @@ pub(crate) async fn process(command: RoomAliasCommand, _body: Vec<&str>) -> Resu
 						let plain_list = aliases
 							.iter()
 							.fold(String::new(), |mut output, (alias, id)| {
-								writeln!(output, "- `{alias}` -> #{id}:{server_name}").unwrap();
+								writeln!(output, "- `{alias}` -> #{id}:{server_name}")
+									.expect("should be able to write to string buffer");
 								output
 							});
 
@@ -120,7 +122,7 @@ pub(crate) async fn process(command: RoomAliasCommand, _body: Vec<&str>) -> Resu
 									escape_html(id.as_ref()),
 									server_name
 								)
-								.unwrap();
+								.expect("should be able to write to string buffer");
 								output
 							});
 

src/admin/room/room_commands.rs

@@ -1,4 +1,4 @@
-use std::fmt::Write as _;
+use std::fmt::Write;
 
 use ruma::{events::room::message::RoomMessageEventContent, OwnedRoomId};
 
@@ -48,7 +48,7 @@ pub(crate) async fn list(_body: Vec<&str>, page: Option<usize>) -> Result<RoomMe
 					members,
 					escape_html(name)
 				)
-				.unwrap();
+				.expect("should be able to write to string buffer");
 				output
 			})
 	);

src/admin/room/room_directory_commands.rs

@@ -1,4 +1,4 @@
-use std::fmt::Write as _;
+use std::fmt::Write;
 
 use ruma::{events::room::message::RoomMessageEventContent, OwnedRoomId};
 
@@ -65,7 +65,7 @@ pub(crate) async fn process(command: RoomDirectoryCommand, _body: Vec<&str>) ->
 							members,
 							escape_html(name.as_ref())
 						)
-						.unwrap();
+						.expect("should be able to write to string buffer");
 						output
 					})
 			);

src/admin/room/room_moderation_commands.rs

@@ -122,7 +122,9 @@ pub(crate) async fn process(command: RoomModerationCommand, body: Vec<&str>) ->
 						&local_user, &room_id
 					);
 
-					_ = leave_room(&local_user, &room_id, None).await;
+					if let Err(e) = leave_room(&local_user, &room_id, None).await {
+						warn!(%e, "Failed to leave room");
+					}
 				}
 			} else {
 				for local_user in services()
@@ -329,7 +331,9 @@ pub(crate) async fn process(command: RoomModerationCommand, body: Vec<&str>) ->
 								 admins too)",
 								&local_user, room_id
 							);
-							_ = leave_room(&local_user, &room_id, None).await;
+							if let Err(e) = leave_room(&local_user, &room_id, None).await {
+								warn!(%e, "Failed to leave room");
+							}
 						}
 					} else {
 						for local_user in services()

src/admin/user/user_commands.rs

@@ -65,7 +65,8 @@ pub(crate) async fn create(
 		.new_user_displayname_suffix
 		.is_empty()
 	{
-		_ = write!(displayname, " {}", services().globals.config.new_user_displayname_suffix);
+		write!(displayname, " {}", services().globals.config.new_user_displayname_suffix)
+			.expect("should be able to write to string buffer");
 	}
 
 	services()

src/api/client_server/account.rs

@@ -1,4 +1,4 @@
-use std::fmt::Write as _;
+use std::fmt::Write;
 
 use register::RegistrationKind;
 use ruma::{
@@ -241,7 +241,8 @@ pub(crate) async fn register_route(body: Ruma<register::v3::Request>) -> Result<
 	// If `new_user_displayname_suffix` is set, registration will push whatever
 	// content is set to the user's display name with a space before it
 	if !services().globals.new_user_displayname_suffix().is_empty() {
-		_ = write!(displayname, " {}", services().globals.config.new_user_displayname_suffix);
+		write!(displayname, " {}", services().globals.config.new_user_displayname_suffix)
+			.expect("should be able to write to string buffer");
 	}
 
 	services()

src/api/client_server/membership.rs

@@ -80,7 +80,9 @@ async fn banned_room_check(user_id: &UserId, room_id: Option<&RoomId>, server_na
 
 					// ignore errors
 					leave_all_rooms(user_id).await;
-					_ = services().users.deactivate_account(user_id);
+					if let Err(e) = services().users.deactivate_account(user_id) {
+						warn!(%e, "Failed to deactivate account");
+					}
 				}
 
 				return Err(Error::BadRequest(
@@ -115,7 +117,9 @@ async fn banned_room_check(user_id: &UserId, room_id: Option<&RoomId>, server_na
 
 					// ignore errors
 					leave_all_rooms(user_id).await;
-					_ = services().users.deactivate_account(user_id);
+					if let Err(e) = services().users.deactivate_account(user_id) {
+						warn!(%e, "Failed to deactivate account");
+					}
 				}
 
 				return Err(Error::BadRequest(
@@ -1548,8 +1552,12 @@ pub async fn leave_all_rooms(user_id: &UserId) {
 		};
 
 		// ignore errors
-		_ = services().rooms.state_cache.forget(&room_id, user_id);
+		if let Err(e) = services().rooms.state_cache.forget(&room_id, user_id) {
-		_ = leave_room(user_id, &room_id, None).await;
+			warn!(%e, "Failed to forget room");
+		}
+		if let Err(e) = leave_room(user_id, &room_id, None).await {
+			warn!(%e, "Failed to leave room");
+		}
 	}
 }
 

src/api/client_server/profile.rs

@@ -12,6 +12,7 @@ use ruma::{
 	presence::PresenceState,
 };
 use serde_json::value::to_raw_value;
+use tracing::warn;
 
 use crate::{
 	service::{pdu::PduBuilder, user_is_local},
@@ -82,11 +83,14 @@ pub(crate) async fn set_displayname_route(
 		);
 		let state_lock = mutex_state.lock().await;
 
-		_ = services()
+		if let Err(e) = services()
 			.rooms
 			.timeline
 			.build_and_append_pdu(pdu_builder, sender_user, &room_id, &state_lock)
-			.await;
+			.await
+		{
+			warn!(%e, "Failed to update/send new display name in room");
+		}
 	}
 
 	if services().globals.allow_local_presence() {
@@ -224,11 +228,14 @@ pub(crate) async fn set_avatar_url_route(
 		);
 		let state_lock = mutex_state.lock().await;
 
-		_ = services()
+		if let Err(e) = services()
 			.rooms
 			.timeline
 			.build_and_append_pdu(pdu_builder, sender_user, &room_id, &state_lock)
-			.await;
+			.await
+		{
+			warn!(%e, "Failed to set/update room with new avatar URL / pfp");
+		}
 	}
 
 	if services().globals.allow_local_presence() {

src/api/client_server/room.rs

@@ -388,7 +388,7 @@ pub(crate) async fn create_room_route(body: Ruma<create_room::v3::Request>) -> R
 			Error::BadRequest(ErrorKind::InvalidParam, "Invalid initial state event.")
 		})?;
 
-		debug_warn!("initial state event: {event:?}");
+		debug_info!("Room creation initial state event: {event:?}");
 
 		// client/appservice workaround: if a user sends an initial_state event with a
 		// state event in there with the content of literally `{}` (not null or empty
@@ -460,7 +460,9 @@ pub(crate) async fn create_room_route(body: Ruma<create_room::v3::Request>) -> R
 	// 8. Events implied by invite (and TODO: invite_3pid)
 	drop(state_lock);
 	for user_id in &body.invite {
-		_ = invite_helper(sender_user, user_id, &room_id, None, body.is_direct).await;
+		if let Err(e) = invite_helper(sender_user, user_id, &room_id, None, body.is_direct).await {
+			warn!(%e, "Failed to send invite");
+		}
 	}
 
 	// Homeserver specific stuff
@@ -815,7 +817,7 @@ pub(crate) async fn upgrade_room_route(body: Ruma<upgrade_room::v3::Request>) ->
 
 	// Modify the power levels in the old room to prevent sending of events and
 	// inviting new users
-	_ = services()
+	services()
 		.rooms
 		.timeline
 		.build_and_append_pdu(

src/core/config/mod.rs

@@ -866,7 +866,7 @@ impl fmt::Display for Config {
 		let mut msg: String = "Active config values:\n\n".to_owned();
 
 		for line in lines.into_iter().enumerate() {
-			let _ = writeln!(msg, "{}: {}", line.1 .0, line.1 .1);
+			writeln!(msg, "{}: {}", line.1 .0, line.1 .1).expect("should be able to write to string buffer");
 		}
 
 		write!(f, "{msg}")

src/database/rocksdb/mod.rs

@@ -5,6 +5,7 @@ extern crate rust_rocksdb;
 
 use std::{
 	collections::HashMap,
+	fmt::Write,
 	sync::{atomic::AtomicU32, Arc},
 };
 
@@ -99,6 +100,7 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 		if !self.old_cfs.contains(&name.to_owned()) {
 			// Create if it didn't exist
 			debug!("Creating new column family in database: {}", name);
+
 			_ = self.rocks.create_cf(name, &self.opts);
 		}
 
@@ -141,22 +143,19 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 	fn memory_usage(&self) -> Result<String> {
 		let mut res = String::new();
 		let stats = get_memory_usage_stats(Some(&[&self.rocks]), Some(&[&self.row_cache]))?;
-		_ = std::fmt::write(
+		writeln!(
-			&mut res,
+			res,
-			format_args!(
+			"Memory buffers: {:.2} MiB\nPending write: {:.2} MiB\nTable readers: {:.2} MiB\nRow cache: {:.2} MiB",
-				"Memory buffers: {:.2} MiB\nPending write: {:.2} MiB\nTable readers: {:.2} MiB\nRow cache: {:.2} MiB\n",
 			stats.mem_table_total as f64 / 1024.0 / 1024.0,
 			stats.mem_table_unflushed as f64 / 1024.0 / 1024.0,
 			stats.mem_table_readers_total as f64 / 1024.0 / 1024.0,
 			self.row_cache.get_usage() as f64 / 1024.0 / 1024.0,
-			),
+		)
-		);
+		.expect("should be able to write to string buffer");
 
 		for (name, cache) in &self.col_cache {
-			_ = std::fmt::write(
+			writeln!(res, "{} cache: {:.2} MiB", name, cache.get_usage() as f64 / 1024.0 / 1024.0,)
-				&mut res,
+				.expect("should be able to write to string buffer");
-				format_args!("{} cache: {:.2} MiB\n", name, cache.get_usage() as f64 / 1024.0 / 1024.0,),
-			);
 		}
 
 		Ok(res)
@@ -217,19 +216,17 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 		let options = BackupEngineOptions::new(path.unwrap())?;
 		let engine = BackupEngine::open(&options, &self.env)?;
 		for info in engine.get_backup_info() {
-			std::fmt::write(
+			writeln!(
-				&mut res,
+				res,
-				format_args!(
+				"#{} {}: {} bytes, {} files",
-					"#{} {}: {} bytes, {} files\n",
 				info.backup_id,
 				DateTime::<Utc>::from_timestamp(info.timestamp, 0)
 					.unwrap_or_default()
 					.to_rfc2822(),
 				info.size,
 				info.num_files,
-				),
 			)
-			.unwrap();
+			.expect("should be able to write to string buffer");
 		}
 
 		Ok(res)
@@ -241,18 +238,12 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 			Ok(files) => {
 				let mut res = String::new();
 				for file in files {
-					let _ = std::fmt::write(
+					writeln!(
-						&mut res,
+						res,
-						format_args!(
 						"<code>L{} {:<13} {:7}+ {:4}- {:9}</code> {}<br>",
-							file.level,
+						file.level, file.name, file.num_entries, file.num_deletions, file.size, file.column_family_name,
-							file.name,
+					)
-							file.num_entries,
+					.expect("should be able to writeln to string buffer");
-							file.num_deletions,
-							file.size,
-							file.column_family_name,
-						),
-					);
 				}
 				Ok(res)
 			},

src/router/run.rs

@@ -81,8 +81,7 @@ pub(crate) async fn start(server: Arc<Server>) -> Result<(), Error> {
 	services().start().await?;
 
 	#[cfg(feature = "systemd")]
-	#[allow(clippy::let_underscore_untyped)] // error[E0658]: attributes on expressions are experimental
+	sd_notify::notify(true, &[sd_notify::NotifyState::Ready]).expect("failed to notify systemd of ready state");
-	let _ = sd_notify::notify(true, &[sd_notify::NotifyState::Ready]);
 
 	debug!("Started");
 	Ok(())
@@ -115,8 +114,7 @@ pub(crate) async fn stop(_server: Arc<Server>) -> Result<(), Error> {
 	drop(s);
 
 	#[cfg(feature = "systemd")]
-	#[allow(clippy::let_underscore_untyped)] // error[E0658]: attributes on expressions are experimental
+	sd_notify::notify(true, &[sd_notify::NotifyState::Stopping]).expect("failed to notify systemd of stopping state");
-	let _ = sd_notify::notify(true, &[sd_notify::NotifyState::Stopping]);
 
 	info!("Shutdown complete.");
 	Ok(())

src/service/globals/updates.rs

@@ -3,7 +3,7 @@ use std::time::Duration;
 use ruma::events::room::message::RoomMessageEventContent;
 use serde::Deserialize;
 use tokio::{task::JoinHandle, time::interval};
-use tracing::{debug, error};
+use tracing::{debug, error, warn};
 
 use crate::{
 	conduit::{Error, Result},
@@ -35,7 +35,9 @@ pub async fn start_check_for_updates_task() -> Result<JoinHandle<()>> {
 				},
 			}
 
-			_ = try_handle_updates().await;
+			if let Err(e) = try_handle_updates().await {
+				warn!(%e, "Failed to check for updates");
+			}
 		}
 	}))
 }