Vendor dependencies

Let's see how I like this workflow.

vendor/tokio/tests/net_lookup_host.rs

@@ -0,0 +1,38 @@
+#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi does not support direct socket operations
+
+use tokio::net;
+use tokio_test::assert_ok;
+
+use std::io;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
+
+#[tokio::test]
+async fn lookup_socket_addr() {
+    let addr: SocketAddr = "127.0.0.1:8000".parse().unwrap();
+
+    let actual = assert_ok!(net::lookup_host(addr).await).collect::<Vec<_>>();
+    assert_eq!(vec![addr], actual);
+}
+
+#[tokio::test]
+async fn lookup_str_socket_addr() {
+    let addr: SocketAddr = "127.0.0.1:8000".parse().unwrap();
+
+    let actual = assert_ok!(net::lookup_host("127.0.0.1:8000").await).collect::<Vec<_>>();
+    assert_eq!(vec![addr], actual);
+}
+
+#[tokio::test]
+async fn resolve_dns() -> io::Result<()> {
+    let mut hosts = net::lookup_host("localhost:3000").await?;
+    let host = hosts.next().unwrap();
+
+    let expected = if host.is_ipv4() {
+        SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 3000)
+    } else {
+        SocketAddr::new(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)), 3000)
+    };
+    assert_eq!(host, expected);
+
+    Ok(())
+}