Start using serial_test for test serialisation

Cargo.toml

@@ -169,6 +169,7 @@ opentelemetry-otlp = "0.14.0"
 opentelemetry_sdk = { version = "0.21.0", features = ["rt-tokio"] }
 proptest = "1.1.0"
 rustup-macros = { path = "rustup-macros" }
+serial_test = "3"
 tempfile = "3.8"
 termcolor = "1.2"
 thiserror = "1.0"

download/Cargo.toml

@@ -35,4 +35,5 @@ hyper = { version = "1.0", default-features = false, features = [
     "server",
 ] }
 hyper-util = { version = "0.1.1", features = ["tokio"] }
+serial_test.workspace = true
 tempfile.workspace = true

download/tests/read-proxy-env.rs

@@ -4,16 +4,14 @@ use std::env::{remove_var, set_var};
 use std::error::Error;
 use std::net::TcpListener;
 use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::Mutex;
 use std::thread;
 use std::time::Duration;
 
 use env_proxy::for_url;
 use reqwest::{Client, Proxy};
+use serial_test::serial;
 use url::Url;
 
-static SERIALISE_TESTS: Mutex<()> = Mutex::new(());
-
 fn scrub_env() {
     remove_var("http_proxy");
     remove_var("https_proxy");
@@ -28,10 +26,8 @@ fn scrub_env() {
 
 // Tests for correctly retrieving the proxy (host, port) tuple from $https_proxy
 #[tokio::test]
+#[serial]
 async fn read_basic_proxy_params() {
-    let _guard = SERIALISE_TESTS
-        .lock()
-        .expect("Unable to lock the test guard");
     scrub_env();
     set_var("https_proxy", "http://proxy.example.com:8080");
     let u = Url::parse("https://www.example.org").ok().unwrap();
@@ -43,12 +39,9 @@ async fn read_basic_proxy_params() {
 
 // Tests to verify if socks feature is available and being used
 #[tokio::test]
+#[serial]
 async fn socks_proxy_request() {
     static CALL_COUNT: AtomicUsize = AtomicUsize::new(0);
-    let _guard = SERIALISE_TESTS
-        .lock()
-        .expect("Unable to lock the test guard");
-
     scrub_env();
     set_var("all_proxy", "socks5://127.0.0.1:1080");