test(providers): isolate environment-proxy test in its own binary

crates/goose-providers/src/api_client.rs

@@ -796,35 +796,6 @@ mod tests {
         );
     }
 
-    #[tokio::test]
-    async fn loopback_transport_does_not_use_environment_proxy() {
-        let proxy = TcpListener::bind("127.0.0.1:0").await.unwrap();
-        let proxy_uri = format!("http://{}", proxy.local_addr().unwrap());
-        let _guard = env_lock::lock_env([
-            ("HTTP_PROXY", Some(proxy_uri.as_str())),
-            ("http_proxy", Some(proxy_uri.as_str())),
-            ("NO_PROXY", Some("")),
-            ("no_proxy", Some("")),
-        ]);
-        let client = ApiClient::new_with_tls(
-            "http://127.0.0.1:9".to_string(),
-            AuthMethod::BearerToken("secret".to_string()),
-            None,
-        )
-        .unwrap()
-        .with_loopback_http_only()
-        .unwrap()
-        .with_header("x-test", "value")
-        .unwrap();
-
-        assert!(client.response_get("models").await.is_err());
-        assert!(
-            tokio::time::timeout(Duration::from_millis(100), proxy.accept())
-                .await
-                .is_err()
-        );
-    }
-
     #[tokio::test]
     async fn loopback_transport_rejects_remote_http_redirect() {
         for status in ["307 Temporary Redirect", "308 Permanent Redirect"] {

crates/goose-providers/tests/loopback_proxy_env.rs

@@ -0,0 +1,37 @@
+//! Isolated in its own test binary: this test mutates process-wide proxy
+//! environment variables, which would otherwise be observed by unrelated
+//! tests in the same process that build HTTP clients.
+
+use std::time::Duration;
+
+use goose_providers::api_client::{ApiClient, AuthMethod};
+use tokio::net::TcpListener;
+
+#[tokio::test]
+async fn loopback_transport_does_not_use_environment_proxy() {
+    let proxy = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let proxy_uri = format!("http://{}", proxy.local_addr().unwrap());
+    let _guard = env_lock::lock_env([
+        ("HTTP_PROXY", Some(proxy_uri.as_str())),
+        ("http_proxy", Some(proxy_uri.as_str())),
+        ("NO_PROXY", Some("")),
+        ("no_proxy", Some("")),
+    ]);
+    let client = ApiClient::new_with_tls(
+        "http://127.0.0.1:9".to_string(),
+        AuthMethod::BearerToken("secret".to_string()),
+        None,
+    )
+    .unwrap()
+    .with_loopback_http_only()
+    .unwrap()
+    .with_header("x-test", "value")
+    .unwrap();
+
+    assert!(client.response_get("models").await.is_err());
+    assert!(
+        tokio::time::timeout(Duration::from_millis(100), proxy.accept())
+            .await
+            .is_err()
+    );
+}