9fecd57a99 2026-10-28 arcade: //! The entry point is private to the binary, so test its public CLI and SMTP
9fecd57a99 2026-10-28 arcade: //! behavior with isolated configuration directories and bounded subprocesses.
9fecd57a99 2026-10-28 arcade: use std::{
9fecd57a99 2026-10-28 arcade: fs::{self, OpenOptions},
9fecd57a99 2026-10-28 arcade: io::{BufRead, BufReader, Write},
9fecd57a99 2026-10-28 arcade: net::{SocketAddr, TcpListener, TcpStream},
9fecd57a99 2026-10-28 arcade: os::unix::fs::{OpenOptionsExt, PermissionsExt},
9fecd57a99 2026-10-28 arcade: path::PathBuf,
9fecd57a99 2026-10-28 arcade: process::{Child, Command, Output, Stdio},
9fecd57a99 2026-10-28 arcade: sync::atomic::{AtomicUsize, Ordering},
9fecd57a99 2026-10-28 arcade: thread,
9fecd57a99 2026-10-28 arcade: time::{Duration, Instant},
9fecd57a99 2026-10-28 arcade: };
9fecd57a99 2026-10-28 arcade: const DEADLINE: Duration = Duration::from_secs(5);
9fecd57a99 2026-10-28 arcade: struct TestDir(PathBuf);
9fecd57a99 2026-10-28 arcade: impl TestDir {
9fecd57a99 2026-10-28 arcade: fn new () -> Self {
9fecd57a99 2026-10-28 arcade: static NEXT: AtomicUsize = AtomicUsize::new(0);
9fecd57a99 2026-10-28 arcade: loop {
9fecd57a99 2026-10-28 arcade: let path = std::env::temp_dir().join(format!("smtp2tg-cli-{}-{}",
9fecd57a99 2026-10-28 arcade: std::process::id(), NEXT.fetch_add(1, Ordering::Relaxed)));
9fecd57a99 2026-10-28 arcade: match fs::create_dir(&path) {
9fecd57a99 2026-10-28 arcade: Ok(()) => return Self(path),
9fecd57a99 2026-10-28 arcade: Err(error) if error.kind() == std::io::ErrorKind::AlreadyExists => continue,
9fecd57a99 2026-10-28 arcade: Err(error) => panic!("Cannot create test directory: {error}"),
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn config (&self, name: &str, text: &str, mode: u32) {
9fecd57a99 2026-10-28 arcade: let path = self.0.join(name);
9fecd57a99 2026-10-28 arcade: let mut file = OpenOptions::new().create_new(true).write(true).mode(0o600)
9fecd57a99 2026-10-28 arcade: .open(&path).unwrap();
9fecd57a99 2026-10-28 arcade: file.write_all(text.as_bytes()).unwrap();
9fecd57a99 2026-10-28 arcade: fs::set_permissions(path, fs::Permissions::from_mode(mode)).unwrap();
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn spawn (&self, args: &[&str]) -> Process {
9fecd57a99 2026-10-28 arcade: Process(Some(Command::new(env!("CARGO_BIN_EXE_smtp2tg"))
9fecd57a99 2026-10-28 arcade: .current_dir(&self.0).args(args)
9fecd57a99 2026-10-28 arcade: .stdin(Stdio::null()).stdout(Stdio::piped()).stderr(Stdio::piped())
9fecd57a99 2026-10-28 arcade: .spawn().unwrap()))
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn run (&self, args: &[&str]) -> Output {
9fecd57a99 2026-10-28 arcade: self.spawn(args).output()
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: impl Drop for TestDir {
9fecd57a99 2026-10-28 arcade: fn drop (&mut self) {
9fecd57a99 2026-10-28 arcade: let _ = fs::remove_dir_all(&self.0);
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: struct Process(Option<Child>);
9fecd57a99 2026-10-28 arcade: impl Process {
9fecd57a99 2026-10-28 arcade: fn output (mut self) -> Output {
9fecd57a99 2026-10-28 arcade: let deadline = Instant::now() + DEADLINE;
9fecd57a99 2026-10-28 arcade: while self.0.as_mut().unwrap().try_wait().unwrap().is_none() {
9fecd57a99 2026-10-28 arcade: assert!(Instant::now() < deadline, "CLI did not exit within {DEADLINE:?}");
9fecd57a99 2026-10-28 arcade: thread::sleep(Duration::from_millis(10));
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: self.0.take().unwrap().wait_with_output().unwrap()
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn connect (&mut self, address: SocketAddr) -> TcpStream {
9fecd57a99 2026-10-28 arcade: let deadline = Instant::now() + DEADLINE;
9fecd57a99 2026-10-28 arcade: loop {
9fecd57a99 2026-10-28 arcade: assert!(self.0.as_mut().unwrap().try_wait().unwrap().is_none(),
9fecd57a99 2026-10-28 arcade: "SMTP server exited before accepting connections");
9fecd57a99 2026-10-28 arcade: if let Ok(stream) = TcpStream::connect_timeout(&address, Duration::from_millis(100)) {
9fecd57a99 2026-10-28 arcade: stream.set_read_timeout(Some(DEADLINE)).unwrap();
9fecd57a99 2026-10-28 arcade: stream.set_write_timeout(Some(DEADLINE)).unwrap();
9fecd57a99 2026-10-28 arcade: return stream;
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: assert!(Instant::now() < deadline, "SMTP server did not start within {DEADLINE:?}");
9fecd57a99 2026-10-28 arcade: thread::sleep(Duration::from_millis(10));
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: impl Drop for Process {
9fecd57a99 2026-10-28 arcade: fn drop (&mut self) {
9fecd57a99 2026-10-28 arcade: if let Some(child) = &mut self.0 {
9fecd57a99 2026-10-28 arcade: let _ = child.kill();
9fecd57a99 2026-10-28 arcade: let _ = child.wait();
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn assert_error (output: Output, expected: &str) {
9fecd57a99 2026-10-28 arcade: let stderr = String::from_utf8_lossy(&output.stderr);
9fecd57a99 2026-10-28 arcade: assert!(!output.status.success(), "Expected failure, stderr: {stderr}");
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains(expected), "Missing {expected:?} in stderr: {stderr}");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn help_succeeds_without_a_configuration_file () {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: for flag in ["-h", "--help"] {
9fecd57a99 2026-10-28 arcade: let output = dir.run(&[flag]);
9fecd57a99 2026-10-28 arcade: assert!(output.status.success());
9fecd57a99 2026-10-28 arcade: let help = String::from_utf8(output.stdout).unwrap();
9fecd57a99 2026-10-28 arcade: for expected in ["SMTP-to-Telegram gateway", env!("CARGO_PKG_VERSION"),
9fecd57a99 2026-10-28 arcade: "-c, --config", "[default: smtp2tg.toml]"] {
9fecd57a99 2026-10-28 arcade: assert!(help.contains(expected), "Missing {expected:?} in help: {help}");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn missing_default_and_explicit_configuration_paths_are_reported () {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: for (args, path) in [
9fecd57a99 2026-10-28 arcade: (vec![], "smtp2tg.toml"),
9fecd57a99 2026-10-28 arcade: (vec!["-c", "missing file.toml"], "missing file.toml"),
9fecd57a99 2026-10-28 arcade: (vec!["--config", "missing file.toml"], "missing file.toml"),
9fecd57a99 2026-10-28 arcade: ] {
9fecd57a99 2026-10-28 arcade: let output = dir.run(&args);
9fecd57a99 2026-10-28 arcade: let stderr = String::from_utf8_lossy(&output.stderr);
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains(path), "Missing path in diagnostic: {stderr}");
9fecd57a99 2026-10-28 arcade: assert_error(output, "Configuration file not found");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn invalid_arguments_fail_before_configuration_loading () {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: for args in [vec!["-c"], vec!["--config"], vec!["--unknown-option"]] {
9fecd57a99 2026-10-28 arcade: let output = dir.run(&args);
9fecd57a99 2026-10-28 arcade: assert_eq!(output.status.code(), Some(2), "arguments: {args:?}");
9fecd57a99 2026-10-28 arcade: assert!(!String::from_utf8_lossy(&output.stderr).contains("Configuration file not found"));
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn insecure_permissions_are_rejected_before_parsing () {
9fecd57a99 2026-10-28 arcade: // Each forbidden permission is independent: group read/write/execute,
9fecd57a99 2026-10-28 arcade: // other read/write/execute, and owner execute.
9fecd57a99 2026-10-28 arcade: for mode in [0o640, 0o620, 0o610, 0o604, 0o602, 0o601, 0o700] {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: dir.config("smtp2tg.toml", "this is not valid TOML", mode);
9fecd57a99 2026-10-28 arcade: let output = dir.run(&[]);
9fecd57a99 2026-10-28 arcade: let stderr = String::from_utf8_lossy(&output.stderr);
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains("Required: 0600"), "mode {mode:o}: {stderr}");
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains("chmod 600"), "mode {mode:o}: {stderr}");
9fecd57a99 2026-10-28 arcade: assert_error(output, "Configuration file permissions are insecure");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn secure_malformed_config_reports_parse_context () {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: // A spaces-containing path must be passed intact, and the selected file
9fecd57a99 2026-10-28 arcade: // must take precedence over an insecure default configuration.
9fecd57a99 2026-10-28 arcade: dir.config("smtp2tg.toml", "ignored", 0o644);
9fecd57a99 2026-10-28 arcade: dir.config("selected config.toml", "api_key = [", 0o600);
9fecd57a99 2026-10-28 arcade: for flag in ["-c", "--config"] {
9fecd57a99 2026-10-28 arcade: let output = dir.run(&[flag, "selected config.toml"]);
9fecd57a99 2026-10-28 arcade: let stderr = String::from_utf8_lossy(&output.stderr);
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains("selected config.toml"));
9fecd57a99 2026-10-28 arcade: assert!(stderr.contains("smtp2tg.toml.example"));
9fecd57a99 2026-10-28 arcade: assert_error(output, "Failed to parse configuration file");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn required_settings_remain_required_after_applying_defaults () {
9fecd57a99 2026-10-28 arcade: for (config, expected) in [
9fecd57a99 2026-10-28 arcade: ("default = 0\n[recipients]\n", "api_key"),
9fecd57a99 2026-10-28 arcade: ("api_key = 'test-api-key'\n[recipients]\n", "default"),
9fecd57a99 2026-10-28 arcade: ("api_key = 'test-api-key'\ndefault = 0\n", "recipients"),
9fecd57a99 2026-10-28 arcade: ] {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: dir.config("smtp2tg.toml", config, 0o600);
9fecd57a99 2026-10-28 arcade: let output = dir.run(&[]);
9fecd57a99 2026-10-28 arcade: assert_error(output, expected);
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: fn smtp_reply (stream: &mut BufReader<TcpStream>) -> String {
9fecd57a99 2026-10-28 arcade: let mut response = String::new();
9fecd57a99 2026-10-28 arcade: loop {
9fecd57a99 2026-10-28 arcade: let mut line = String::new();
9fecd57a99 2026-10-28 arcade: assert!(stream.read_line(&mut line).unwrap() > 0, "SMTP connection closed: {response}");
9fecd57a99 2026-10-28 arcade: let more = line.as_bytes().get(3) == Some(&b'-');
9fecd57a99 2026-10-28 arcade: response.push_str(&line);
9fecd57a99 2026-10-28 arcade: if !more {
9fecd57a99 2026-10-28 arcade: return response;
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: #[test]
9fecd57a99 2026-10-28 arcade: fn entry_point_serves_smtp_with_defaults_and_configuration_overrides () {
9fecd57a99 2026-10-28 arcade: for (overrides, hostname, allowed, denied) in [
9fecd57a99 2026-10-28 arcade: ("", "smtp.2.tg", "localhost", "outside.invalid"),
9fecd57a99 2026-10-28 arcade: ("hostname = 'custom.smtp'\ndomains = ['example.com']\nfields = []\n",
9fecd57a99 2026-10-28 arcade: "custom.smtp", "example.com", "localhost"),
9fecd57a99 2026-10-28 arcade: ] {
9fecd57a99 2026-10-28 arcade: let dir = TestDir::new();
9fecd57a99 2026-10-28 arcade: let reservation = TcpListener::bind("127.0.0.1:0").unwrap();
9fecd57a99 2026-10-28 arcade: let address = reservation.local_addr().unwrap();
9fecd57a99 2026-10-28 arcade: dir.config("smtp2tg.toml", &format!(
9fecd57a99 2026-10-28 arcade: "api_key = 'test-api-key'\ndefault = 0\nlisten_on = '{address}'\n{overrides}[recipients]\n"), 0o600);
9fecd57a99 2026-10-28 arcade: drop(reservation);
9fecd57a99 2026-10-28 arcade: let mut process = dir.spawn(&[]);
9fecd57a99 2026-10-28 arcade: let mut stream = BufReader::new(process.connect(address));
9fecd57a99 2026-10-28 arcade: let banner = smtp_reply(&mut stream);
9fecd57a99 2026-10-28 arcade: assert!(banner.starts_with("220 "), "{banner}");
9fecd57a99 2026-10-28 arcade: assert!(banner.contains(hostname), "{banner}");
9fecd57a99 2026-10-28 arcade: for (command, code) in [
9fecd57a99 2026-10-28 arcade: ("EHLO test.local\r\n".into(), "250"),
9fecd57a99 2026-10-28 arcade: ("MAIL FROM:<sender@example.org>\r\n".into(), "250"),
9fecd57a99 2026-10-28 arcade: (format!("RCPT TO:<user@{allowed}>\r\n"), "250"),
9fecd57a99 2026-10-28 arcade: (format!("RCPT TO:<user@{denied}>\r\n"), "550"),
9fecd57a99 2026-10-28 arcade: ("QUIT\r\n".into(), "221"),
9fecd57a99 2026-10-28 arcade: ] {
9fecd57a99 2026-10-28 arcade: stream.get_mut().write_all(command.as_bytes()).unwrap();
9fecd57a99 2026-10-28 arcade: let reply = smtp_reply(&mut stream);
9fecd57a99 2026-10-28 arcade: assert!(reply.starts_with(code), "command {command:?}: {reply}");
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }
9fecd57a99 2026-10-28 arcade: }