fix(core): specialize output for open file when no runtime

Author: joelwurtz

sqlx-core/src/fs.rs

@@ -3,9 +3,6 @@ use std::fs::Metadata;
 use std::io;
 use std::path::{Path, PathBuf};
 
-use cfg_if::cfg_if;
-
-use crate::io::AsyncRead;
 use crate::rt;
 
 pub struct ReadDir {
@@ -98,17 +95,21 @@ impl ReadDir {
     }
 }
 
-pub async fn open_file<P: AsRef<Path>>(path: P) -> Result<impl AsyncRead + Unpin, io::Error> {
-    cfg_if! {
-        if #[cfg(all(feature = "_rt-async-io", not(feature = "_rt-tokio")))] {
-            async_fs::File::open(path).await
-        } else {
-            #[cfg(feature = "_rt-tokio")]
-            if rt::rt_tokio::available() {
-                return tokio::fs::File::open(path).await;
-            }
-
-            rt::missing_rt(path)
-        }
+#[cfg(feature = "_rt-tokio")]
+pub async fn open_file<P: AsRef<Path>>(path: P) -> Result<tokio::fs::File, io::Error> {
+    if rt::rt_tokio::available() {
+        return tokio::fs::File::open(path).await;
     }
+
+    rt::missing_rt(path);
+}
+
+#[cfg(all(feature = "_rt-async-io", not(feature = "_rt-tokio")))]
+pub async fn open_file<P: AsRef<Path>>(path: P) -> Result<async_fs::File, io::Error> {
+    async_fs::File::open(path).await
+}
+
+#[cfg(all(not(feature = "_rt-async-io"), not(feature = "_rt-tokio")))]
+pub async fn open_file<P: AsRef<Path>>(path: P) -> Result<futures_util::io::Empty, io::Error> {
+    rt::missing_rt(path)
 }