Enforce cargo fmt in CI

.github/workflows/test.yml

@@ -56,3 +56,35 @@ jobs:
       - name: Check library code with minimum supported Rust version
         run: |
           just check --lib --locked
+
+  format:
+    name: Format
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Install rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+      - name: Check formatting
+        run: cargo fmt --all -- --check
+
+  format-unstable:
+    name: Format (unstable)
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Install rust nightly toolchain
+        uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: rustfmt
+      - name: Check formatting (unstable)
+        run: cargo fmt --all -- --check --config-path .rustfmt.unstable.toml
+      - if: ${{ failure() }}
+        run: echo "Nightly formatting check failed. Please run \`cargo +nightly fmt-unstable\`"

ktls/src/ktls_stream.rs

@@ -4,7 +4,7 @@ use std::pin::Pin;
 use std::task;
 
 use nix::errno::Errno;
-use nix::sys::socket::{ControlMessageOwned, MsgFlags, SockaddrIn, TlsGetRecordType, recvmsg};
+use nix::sys::socket::{recvmsg, ControlMessageOwned, MsgFlags, SockaddrIn, TlsGetRecordType};
 use num_enum::FromPrimitive;
 use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
 
@@ -228,7 +228,10 @@ where
                         // https://www.rfc-editor.org/info/rfc9846/#appendix-B.3
                         const MSG_NEW_SESSION_TICKET: u8 = 4;
                         const MSG_KEY_UPDATE: u8 = 24;
-                        let message_type = r.iovs().next().and_then(|iov| iov.first());
+                        let message_type = r
+                            .iovs()
+                            .next()
+                            .and_then(|iov| iov.first());
                         match message_type {
                             Some(&MSG_KEY_UPDATE) => {
                                 // KeyUpdate is fatal: This crate cannot switch traffic

ktls/src/lib.rs

@@ -27,7 +27,7 @@ use tokio::net::{TcpListener, TcpStream};
 pub use crate::async_read_ready::AsyncReadReady;
 pub use crate::cork_stream::CorkStream;
 pub use crate::ffi::CryptoInfo;
-use crate::ffi::{KtlsCompatibilityError, setup_tls_info, setup_ulp};
+use crate::ffi::{setup_tls_info, setup_ulp, KtlsCompatibilityError};
 pub use crate::ktls_stream::KtlsStream;
 
 #[derive(Debug, Default)]