feat: add support for tokio

.github/workflows/ci.yml

@@ -38,11 +38,23 @@ jobs:
         command:  check
         args: --benches
 
-    - name: tests
+    - name: tests tokio
       uses: actions-rs/cargo@v1
       with:
         command: test
-        args: --all --no-default-features --features file-transport smtp-transport
+        args: --all --no-default-features --features file-transport,smtp-transport,runtime-tokio
+
+    - name: tests tokio with socks5
+      uses: actions-rs/cargo@v1
+      with:
+        command: test
+        args: --all --no-default-features --features file-transport,smtp-transport,runtime-tokio,socks5
+
+    - name: tests async-std
+      uses: actions-rs/cargo@v1
+      with:
+        command: test
+        args: --all --no-default-features --features file-transport,smtp-transport,runtime-async-std
 
   check_fmt_and_docs:
     name: Checking fmt and docs
@@ -75,4 +87,3 @@ jobs:
       - uses: actions-rs/clippy-check@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features

Cargo.toml

@@ -19,40 +19,54 @@ is-it-maintained-open-issues = { repository = "async-email/async-smtp" }
 
 [dependencies]
 log = "^0.4"
-nom = { version = "^5.0", optional = true }
+async-trait = "0.1.17"
+pin-project = "1"
+pin-utils = "0.1.0"
+thiserror = "1.0.9"
+futures = "0.3.21"
+
+nom = { version = "^7.0", optional = true }
 bufstream = { version = "^0.1", optional = true }
 base64 = { version = "^0.13", optional = true }
 hostname = { version = "0.3.1", optional = true }
 serde = { version = "^1.0", optional = true }
 serde_json = { version = "^1.0", optional = true }
 serde_derive = { version = "^1.0", optional = true }
-fast-socks5 = { version = "^0.4", optional = true }
-async-native-tls = { version = "0.3.3" }
-async-std = { version = "1.6.0", features = ["unstable"] }
-async-trait = "0.1.17"
-pin-project = "1"
-pin-utils = "0.1.0"
-thiserror = "1.0.9"
+fast-socks5 = { version = "^0.8", optional = true }
+
+async-std = { version = "1.11", features = ["unstable"], optional = true }
+tokio = { version = "1", features = ["fs", "rt", "time", "net"], optional = true }
+async-native-tls = { version = "0.4", default-features = false }
+
 
 [dev-dependencies]
-env_logger = "^0.8"
+env_logger = "^0.9"
 glob = "^0.3"
 criterion = "^0.3"
-async-attributes = "1.1.1"
+async-std = { version = "1.11", features = ["unstable", "attributes"] }
+tokio = { version = "1", features = ["fs", "rt", "time", "net", "macros"] }
 
 [[bench]]
 name = "transport_smtp"
 harness = false
 
 [features]
-default = ["file-transport", "smtp-transport", "sendmail-transport"]
-unstable = []
+default = [
+  "file-transport", 
+  "smtp-transport", 
+  "sendmail-transport",
+  "runtime-tokio"
+]
+
 serde-impls = ["serde", "serde_derive"]
 file-transport = ["serde-impls", "serde_json"]
 smtp-transport = ["bufstream", "base64", "nom", "hostname"]
 sendmail-transport = []
 native-tls-vendored = ["async-native-tls/vendored"]
 socks5 = ["fast-socks5"]
+runtime-async-std = ["async-std", "async-native-tls/runtime-async-std"]
+runtime-tokio = ["tokio", "async-native-tls/runtime-tokio"]
+
 
 [[example]]
 name = "smtp"

src/file/error.rs

@@ -1,6 +1,6 @@
 //! Error and result type for file transport
 
-use async_std::io;
+use futures::io;
 
 /// An enum of all error kinds.
 #[derive(thiserror::Error, Debug)]

src/file/mod.rs

@@ -3,12 +3,14 @@
 //! It can be useful for testing purposes, or if you want to keep track of sent messages.
 //!
 
+use std::path::Path;
 use std::{path::PathBuf, time::Duration};
 
-use async_std::fs::File;
-use async_std::path::Path;
-use async_std::prelude::*;
+#[cfg(feature = "runtime-async-std")]
+use async_std::fs::write;
 use async_trait::async_trait;
+#[cfg(feature = "runtime-tokio")]
+use tokio::fs::write;
 
 use crate::file::error::FileResult;
 use crate::Envelope;
@@ -64,10 +66,8 @@ impl<'a> Transport<'a> for FileTransport {
             message: email.message_to_string().await?.as_bytes().to_vec(),
         })?;
 
-        File::create(file)
-            .await?
-            .write_all(serialized.as_bytes())
-            .await?;
+        write(file, serialized.as_bytes()).await?;
+
         Ok(())
     }
 

src/lib.rs

@@ -11,6 +11,12 @@
     clippy::unwrap_used
 )]
 
+#[cfg(not(any(feature = "runtime-tokio", feature = "runtime-async-std")))]
+compile_error!("one of 'runtime-async-std' or 'runtime-tokio' features must be enabled");
+
+#[cfg(all(feature = "runtime-tokio", feature = "runtime-async-std"))]
+compile_error!("only one of 'runtime-async-std' or 'runtime-tokio' features must be enabled");
+
 pub mod error;
 #[cfg(feature = "file-transport")]
 pub mod file;
@@ -53,3 +59,39 @@ pub trait Transport<'a> {
         timeout: Option<&Duration>,
     ) -> Self::Result;
 }
+
+#[macro_export]
+macro_rules! async_test {
+    ($name:ident, $block:block) => {
+        #[cfg(feature = "runtime-tokio")]
+        #[tokio::test]
+        async fn $name() {
+            $block
+        }
+
+        #[cfg(feature = "runtime-async-std")]
+        #[async_std::test]
+        async fn $name() {
+            $block
+        }
+    };
+}
+
+#[macro_export]
+macro_rules! async_test_ignore {
+    ($name:ident, $block:block) => {
+        #[cfg(feature = "runtime-tokio")]
+        #[tokio::test]
+        #[ignore]
+        async fn $name() {
+            $block
+        }
+
+        #[cfg(feature = "runtime-async-std")]
+        #[async_std::test]
+        #[ignore]
+        async fn $name() {
+            $block
+        }
+    };
+}

src/sendmail/error.rs

@@ -2,7 +2,7 @@
 
 use std::string::FromUtf8Error;
 
-use async_std::io;
+use futures::io;
 
 /// An enum of all error kinds.
 #[derive(thiserror::Error, Debug)]
@@ -16,6 +16,9 @@ pub enum Error {
     /// IO error
     #[error("io error: {0}")]
     Io(#[from] io::Error),
+    #[cfg(feature = "runtime-tokio")]
+    #[error("join: {0}")]
+    Join(#[from] tokio::task::JoinError),
 }
 
 /// sendmail result type

src/sendmail/mod.rs

@@ -5,7 +5,6 @@ use crate::sendmail::error::SendmailResult;
 use crate::SendableEmail;
 use crate::Transport;
 
-use async_std::prelude::*;
 use async_trait::async_trait;
 use log::info;
 use std::convert::AsRef;
@@ -15,6 +14,12 @@ use std::{
     time::Duration,
 };
 
+#[cfg(feature = "runtime-tokio")]
+use tokio::{io::AsyncReadExt, task::spawn_blocking};
+
+#[cfg(feature = "runtime-async-std")]
+use async_std::{io::ReadExt, task::spawn_blocking};
+
 pub mod error;
 
 /// Sends an email using the `sendmail` command
@@ -63,7 +68,7 @@ impl<'a> Transport<'a> for SendmailTransport {
         let _ = email.message().read_to_string(&mut message_content).await;
 
         // TODO: Convert to real async, once async-std has a process implementation.
-        let output = async_std::task::spawn_blocking(move || {
+        let res = spawn_blocking(move || {
             // Spawn the sendmail command
             let mut process = Command::new(command)
                 .arg("-i")
@@ -83,14 +88,22 @@ impl<'a> Transport<'a> for SendmailTransport {
 
             info!("Wrote {} message to stdin", message_id);
 
-            process.wait_with_output()
+            let output = process.wait_with_output()?;
+            if output.status.success() {
+                Ok(())
+            } else {
+                Err(error::Error::Client(String::from_utf8(output.stderr)?))
+            }
         })
-        .await?;
+        .await;
 
-        if output.status.success() {
-            Ok(())
-        } else {
-            Err(error::Error::Client(String::from_utf8(output.stderr)?))
+        #[cfg(feature = "runtime-tokio")]
+        {
+            res?
+        }
+        #[cfg(feature = "runtime-async-std")]
+        {
+            res
         }
     }
 

src/smtp/client/codec.rs

@@ -1,5 +1,9 @@
-use async_std::io::{self, Write};
-use async_std::prelude::*;
+#[cfg(feature = "runtime-async-std")]
+use async_std::io::{Write, WriteExt};
+#[cfg(feature = "runtime-tokio")]
+use tokio::io::{AsyncWrite as Write, AsyncWriteExt};
+
+use futures::io;
 
 /// The codec used for transparency
 #[derive(Default, Clone, Copy, Debug)]