add some missing tokio::fs function tests etc.

tokio/tests/fs_canonicalize_dir.rs

@@ -0,0 +1,22 @@
+#![warn(rust_2018_idioms)]
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
+
+use tokio::fs;
+
+#[tokio::test]
+#[cfg(unix)]
+async fn canonicalize_root_dir_unix() {
+    assert_eq!(fs::canonicalize("/.").await.unwrap().to_str().unwrap(), "/");
+}
+
+#[tokio::test]
+#[cfg(windows)]
+async fn canonicalize_root_dir_windows() {
+    // 2-step let bindings due to Rust memory semantics
+    let dir_path = fs::canonicalize("C:\\.\\").await.unwrap();
+
+    let dir_name = dir_path.to_str().unwrap();
+
+    assert!(dir_name.starts_with("\\\\"));
+    assert!(dir_name.ends_with("C:\\"));
+}

tokio/tests/fs_copy.rs

@@ -1,5 +1,5 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi does not support file operations
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
 
 use tempfile::tempdir;
 use tokio::fs;

tokio/tests/fs_dir.rs

@@ -1,5 +1,5 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi does not support directory operations
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
 
 use tokio::fs;
 use tokio_test::{assert_err, assert_ok};
@@ -45,6 +45,27 @@ async fn build_dir() {
     );
 }
 
+#[tokio::test]
+#[cfg(unix)]
+async fn build_dir_mode_read_only() {
+    let base_dir = tempdir().unwrap();
+    let new_dir = base_dir.path().join("abc");
+
+    assert_ok!(
+        fs::DirBuilder::new()
+            .recursive(true)
+            .mode(0o444)
+            .create(&new_dir)
+            .await
+    );
+
+    assert!(fs::metadata(new_dir)
+        .await
+        .expect("metadata result")
+        .permissions()
+        .readonly());
+}
+
 #[tokio::test]
 async fn remove() {
     let base_dir = tempdir().unwrap();
@@ -85,3 +106,21 @@ async fn read_inherent() {
         vec!["aa".to_string(), "bb".to_string(), "cc".to_string()]
     );
 }
+
+#[tokio::test]
+async fn read_dir_entry_info() {
+    let temp_dir = tempdir().unwrap();
+
+    let file_path = temp_dir.path().join("a.txt");
+
+    fs::write(&file_path, b"Hello File!").await.unwrap();
+
+    let mut dir = fs::read_dir(temp_dir.path()).await.unwrap();
+
+    let first_entry = dir.next_entry().await.unwrap().unwrap();
+
+    assert_eq!(first_entry.path(), file_path);
+    assert_eq!(first_entry.file_name(), "a.txt");
+    assert!(first_entry.metadata().await.unwrap().is_file());
+    assert!(first_entry.file_type().await.unwrap().is_file());
+}

tokio/tests/fs_file.rs

@@ -1,5 +1,5 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi does not support file operations
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
 
 use std::io::prelude::*;
 use tempfile::NamedTempFile;
@@ -87,20 +87,121 @@ async fn coop() {
     panic!("did not yield");
 }
 
+#[tokio::test]
+async fn write_to_clone() {
+    let tempfile = tempfile();
+
+    let file = File::create(tempfile.path()).await.unwrap();
+    let mut clone = file.try_clone().await.unwrap();
+
+    clone.write_all(HELLO).await.unwrap();
+    clone.flush().await.unwrap();
+
+    let contents = std::fs::read(tempfile.path()).unwrap();
+    assert_eq!(contents, HELLO);
+}
+
+#[tokio::test]
+async fn write_into_std() {
+    let tempfile = tempfile();
+
+    let file = File::create(tempfile.path()).await.unwrap();
+    let mut std_file = file.into_std().await;
+
+    std_file.write_all(HELLO).unwrap();
+
+    let contents = std::fs::read(tempfile.path()).unwrap();
+    assert_eq!(contents, HELLO);
+}
+
+#[tokio::test]
+async fn write_into_std_immediate() {
+    let tempfile = tempfile();
+
+    let file = File::create(tempfile.path()).await.unwrap();
+    let mut std_file = file.try_into_std().unwrap();
+
+    std_file.write_all(HELLO).unwrap();
+
+    let contents = std::fs::read(tempfile.path()).unwrap();
+    assert_eq!(contents, HELLO);
+}
+
+#[tokio::test]
+async fn read_file_from_std() {
+    let mut tempfile = tempfile();
+    tempfile.write_all(HELLO).unwrap();
+
+    let std_file = std::fs::File::open(tempfile.path()).unwrap();
+    let mut file = File::from(std_file);
+
+    let mut buf = [0; 1024];
+    let n = file.read(&mut buf).await.unwrap();
+    assert_eq!(n, HELLO.len());
+    assert_eq!(&buf[..n], HELLO);
+}
+
 fn tempfile() -> NamedTempFile {
     NamedTempFile::new().unwrap()
 }
 
 #[tokio::test]
 #[cfg(unix)]
-async fn unix_fd() {
+async fn file_debug_fmt() {
+    let tempfile = tempfile();
+
+    let file = File::open(tempfile.path()).await.unwrap();
+
+    assert_eq!(
+        &format!("{:?}", file)[0..33],
+        "tokio::fs::File { std: File { fd:"
+    );
+}
+
+#[tokio::test]
+#[cfg(windows)]
+async fn file_debug_fmt() {
+    let tempfile = tempfile();
+
+    let file = File::open(tempfile.path()).await.unwrap();
+
+    assert_eq!(
+        &format!("{:?}", file)[0..37],
+        "tokio::fs::File { std: File { handle:"
+    );
+}
+
+#[tokio::test]
+#[cfg(unix)]
+async fn unix_fd_is_valid() {
     use std::os::unix::io::AsRawFd;
     let tempfile = tempfile();
 
     let file = File::create(tempfile.path()).await.unwrap();
     assert!(file.as_raw_fd() as u64 > 0);
 }
 
+#[tokio::test]
+#[cfg(unix)]
+async fn read_file_from_unix_fd() {
+    use std::os::unix::io::AsRawFd;
+    use std::os::unix::io::FromRawFd;
+
+    let mut tempfile = tempfile();
+    tempfile.write_all(HELLO).unwrap();
+
+    let file1 = File::open(tempfile.path()).await.unwrap();
+    let raw_fd = file1.as_raw_fd();
+    assert!(raw_fd > 0);
+
+    let mut file2 = unsafe { File::from_raw_fd(raw_fd) };
+
+    let mut buf = [0; 1024];
+    let n = file2.read(&mut buf).await.unwrap();
+    assert_eq!(n, HELLO.len());
+    assert_eq!(&buf[..n], HELLO);
+}
+
 #[tokio::test]
 #[cfg(windows)]
 async fn windows_handle() {

tokio/tests/fs_link.rs

@@ -1,10 +1,9 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi does not support file operations
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
 
 use tokio::fs;
 
-use std::io::prelude::*;
-use std::io::BufReader;
+use std::io::Write;
 use tempfile::tempdir;
 
 #[tokio::test]
@@ -13,24 +12,23 @@ async fn test_hard_link() {
     let src = dir.path().join("src.txt");
     let dst = dir.path().join("dst.txt");
 
-    {
-        let mut file = std::fs::File::create(&src).unwrap();
-        file.write_all(b"hello").unwrap();
-    }
+    std::fs::File::create(&src)
+        .unwrap()
+        .write_all(b"hello")
+        .unwrap();
 
-    let dst_2 = dst.clone();
+    fs::hard_link(&src, &dst).await.unwrap();
 
-    assert!(fs::hard_link(src, dst_2.clone()).await.is_ok());
+    std::fs::File::create(&src)
+        .unwrap()
+        .write_all(b"new-data")
+        .unwrap();
 
-    let mut content = String::new();
+    let content = fs::read(&dst).await.unwrap();
+    assert_eq!(content, b"new-data");
 
-    {
-        let file = std::fs::File::open(dst).unwrap();
-        let mut reader = BufReader::new(file);
-        reader.read_to_string(&mut content).unwrap();
-    }
-
-    assert!(content == "hello");
+    // test that this is not a symlink:
+    assert!(fs::read_link(&dst).await.is_err());
 }
 
 #[cfg(unix)]
@@ -40,25 +38,20 @@ async fn test_symlink() {
     let src = dir.path().join("src.txt");
     let dst = dir.path().join("dst.txt");
 
-    {
-        let mut file = std::fs::File::create(&src).unwrap();
-        file.write_all(b"hello").unwrap();
-    }
-
-    let src_2 = src.clone();
-    let dst_2 = dst.clone();
-
-    assert!(fs::symlink(src_2.clone(), dst_2.clone()).await.is_ok());
+    std::fs::File::create(&src)
+        .unwrap()
+        .write_all(b"hello")
+        .unwrap();
 
-    let mut content = String::new();
+    fs::symlink(&src, &dst).await.unwrap();
 
-    {
-        let file = std::fs::File::open(dst.clone()).unwrap();
-        let mut reader = BufReader::new(file);
-        reader.read_to_string(&mut content).unwrap();
-    }
+    std::fs::File::create(&src)
+        .unwrap()
+        .write_all(b"new-data")
+        .unwrap();
 
-    assert!(content == "hello");
+    let content = fs::read(&dst).await.unwrap();
+    assert_eq!(content, b"new-data");
 
     let read = fs::read_link(dst.clone()).await.unwrap();
     assert!(read == src);

tokio/tests/fs_open_options.rs

@@ -0,0 +1,80 @@
+#![warn(rust_2018_idioms)]
+#![cfg(all(feature = "full", not(tokio_wasi)))] // WASI does not support all fs operations
+
+use std::io::Write;
+use tempfile::NamedTempFile;
+use tokio::fs::OpenOptions;
+use tokio::io::AsyncReadExt;
+
+const HELLO: &[u8] = b"hello world...";
+
+#[tokio::test]
+async fn open_with_open_options_and_read() {
+    let mut tempfile = NamedTempFile::new().unwrap();
+    tempfile.write_all(HELLO).unwrap();
+
+    let mut file = OpenOptions::new().read(true).open(tempfile).await.unwrap();
+
+    let mut buf = [0; 1024];
+    let n = file.read(&mut buf).await.unwrap();
+
+    assert_eq!(n, HELLO.len());
+    assert_eq!(&buf[..n], HELLO);
+}
+
+#[tokio::test]
+async fn open_options_write() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().write(true)).contains("write: true"));
+}
+
+#[tokio::test]
+async fn open_options_append() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().append(true)).contains("append: true"));
+}
+
+#[tokio::test]
+async fn open_options_truncate() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().truncate(true)).contains("truncate: true"));
+}
+
+#[tokio::test]
+async fn open_options_create() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().create(true)).contains("create: true"));
+}
+
+#[tokio::test]
+async fn open_options_create_new() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().create_new(true)).contains("create_new: true"));
+}
+
+#[tokio::test]
+#[cfg(unix)]
+async fn open_options_mode() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(format!("{:?}", OpenOptions::new().mode(0o644)).contains("mode: 420 "));
+}
+
+#[tokio::test]
+#[cfg(target_os = "linux")]
+async fn open_options_custom_flags_linux() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(
+        format!("{:?}", OpenOptions::new().custom_flags(libc::O_TRUNC))
+            .contains("custom_flags: 512,")
+    );
+}
+
+#[tokio::test]
+#[cfg(any(target_os = "freebsd", target_os = "macos"))]
+async fn open_options_custom_flags_bsd_family() {
+    // TESTING HACK: use Debug output to check the stored data
+    assert!(
+        format!("{:?}", OpenOptions::new().custom_flags(libc::O_NOFOLLOW))
+            .contains("custom_flags: 256,")
+    );
+}