fix(postgres): enable whoami/std feature

Commit 1dd526a bumped whoami to v2, but
it seems that version now needs to have the `std` feature enabled to do
anything useful.

In earlier sqlx versions, connection strings like `postgresql:///dbname`
correctly used the current user's name, matching psql's behavior. Now,
it falls back to `anonymous`. Enabling the `std` feature fixes that.

Author: svnrb

sqlx-postgres/Cargo.toml

@@ -64,7 +64,7 @@ num-bigint = { version = "0.4.3", optional = true }
 smallvec = { version = "1.13.1" }
 stringprep = "0.1.2"
 tracing = { version = "0.1.37", features = ["log"] }
-whoami = { version = "2.0.2", default-features = false }
+whoami = { version = "2.0.2", default-features = false, features = ["std"] }
 
 dotenvy.workspace = true
 thiserror.workspace = true

sqlx-postgres/src/options/parse.rs

@@ -5,6 +5,9 @@ use sqlx_core::Url;
 use std::net::IpAddr;
 use std::str::FromStr;
 
+#[cfg(all(test, unix, not(target_arch = "wasm32")))]
+use std::sync::Mutex;
+
 impl PgConnectOptions {
     pub(crate) fn parse_from_url(url: &Url) -> Result<Self, Error> {
         let mut options = Self::new_without_pgpass();
@@ -340,3 +343,32 @@ fn built_url_can_be_parsed() {
 
     assert!(parsed.is_ok());
 }
+
+#[cfg(all(test, unix, not(target_arch = "wasm32")))]
+struct PgUserTestGuard(Option<std::ffi::OsString>);
+
+#[cfg(all(test, unix, not(target_arch = "wasm32")))]
+impl Drop for PgUserTestGuard {
+    fn drop(&mut self) {
+        if let Some(old_pguser) = &self.0 {
+            std::env::set_var("PGUSER", old_pguser);
+        } else {
+            std::env::remove_var("PGUSER");
+        }
+    }
+}
+
+#[test]
+#[cfg(all(unix, not(target_arch = "wasm32")))]
+fn it_uses_the_os_username_when_url_omits_user() {
+    static ENV_LOCK: Mutex<()> = Mutex::new(());
+
+    let _guard = ENV_LOCK.lock().unwrap();
+    let _pguser_guard = PgUserTestGuard(std::env::var_os("PGUSER"));
+
+    std::env::remove_var("PGUSER");
+
+    let opts = PgConnectOptions::from_str("postgresql:///database").unwrap();
+
+    assert_ne!(opts.username, "anonymous");
+}