refactor: remove internal proxy sys cache (#2442)

This removes some cache code that would only check for system proxies one time. Now it will check every time a `Client` is built.

Technically, removes the crate feature `__internal_proxy_sys_no_cache`, but that was unstable and you weren't using it, right?

Closes #2441

.github/workflows/ci.yml

@@ -91,16 +91,12 @@ jobs:
 
         include:
           - name: linux / stable
-            test-features: "--features __internal_proxy_sys_no_cache"
           - name: linux / beta
             rust: beta
-            test-features: "--features __internal_proxy_sys_no_cache"
           # - name: linux / nightly
           #   rust: nightly
-          #   test-features: "--features __internal_proxy_sys_no_cache"
           - name: macOS / stable
             os: macOS-latest
-            test-features: "--features __internal_proxy_sys_no_cache"
 
           - name: windows / stable-x86_64-msvc
             os: windows-latest
@@ -272,7 +268,7 @@ jobs:
         run: |
           cargo clean
           cargo update -Z minimal-versions
-          cargo update -p proc-macro2 --precise 1.0.62
+          cargo update -p proc-macro2 --precise 1.0.87
           cargo check
           cargo check --all-features
 

src/proxy.rs

@@ -7,7 +7,6 @@ use crate::into_url::{IntoUrl, IntoUrlSealed};
 use crate::Url;
 use http::{header::HeaderValue, Uri};
 use ipnet::IpNet;
-use once_cell::sync::Lazy;
 use percent_encoding::percent_decode;
 use std::collections::HashMap;
 use std::env;
@@ -280,13 +279,9 @@ impl Proxy {
     }
 
     pub(crate) fn system() -> Proxy {
-        let mut proxy = if cfg!(feature = "__internal_proxy_sys_no_cache") {
-            Proxy::new(Intercept::System(Arc::new(get_sys_proxies(
-                get_from_platform(),
-            ))))
-        } else {
-            Proxy::new(Intercept::System(SYS_PROXIES.clone()))
-        };
+        let mut proxy = Proxy::new(Intercept::System(Arc::new(get_sys_proxies(
+            get_from_platform(),
+        ))));
         proxy.no_proxy = NoProxy::from_env();
         proxy
     }
@@ -876,9 +871,6 @@ impl Dst for Uri {
     }
 }
 
-static SYS_PROXIES: Lazy<Arc<SystemProxyMap>> =
-    Lazy::new(|| Arc::new(get_sys_proxies(get_from_platform())));
-
 /// Get system proxies information.
 ///
 /// All platforms will check for proxy settings via environment variables.

tests/proxy.rs

@@ -163,7 +163,6 @@ async fn test_no_proxy() {
     assert_eq!(res.status(), reqwest::StatusCode::OK);
 }
 
-#[cfg_attr(not(feature = "__internal_proxy_sys_no_cache"), ignore)]
 #[tokio::test]
 async fn test_using_system_proxy() {
     let url = "http://not.a.real.sub.hyper.rs/prox";
@@ -175,9 +174,6 @@ async fn test_using_system_proxy() {
         async { http::Response::default() }
     });
 
-    // Note: we're relying on the `__internal_proxy_sys_no_cache` feature to
-    // check the environment every time.
-
     // save system setting first.
     let system_proxy = env::var("http_proxy");
     // set-up http proxy.