Port test_wwrite_to_fd

fish-rust/src/wutil/mod.rs

@@ -5,6 +5,7 @@
 pub mod gettext;
 pub mod printf;
 #[cfg(test)]
+#[allow(unused_imports)] // Easy way to suppress warnings while we have two testing modes.
 mod tests;
 pub mod wcstod;
 pub mod wcstoi;

fish-rust/src/wutil/tests.rs

@@ -1,3 +1,10 @@
+use crate::ffi_tests::add_test;
+use libc::{c_void, O_CREAT, O_RDWR, O_TRUNC, SEEK_SET};
+use rand::random;
+use std::ffi::CString;
+
+use crate::fallback::fish_mkstemp_cloexec;
+
 use super::*;
 
 #[test]
@@ -49,3 +56,42 @@ fn test_wdirname_wbasename() {
     assert_eq!(wdirname(&longpath), longpath_dir);
     assert_eq!(wbasename(&longpath), "overlong"L);
 }
+
+add_test!("test_wwrite_to_fd", || {
+    let (fd, filename) =
+        fish_mkstemp_cloexec(CString::new("/tmp/fish_test_wwrite.XXXXXX").unwrap());
+    {
+        let mut tmpfd = AutoCloseFd::new(fd);
+        assert!(tmpfd.is_valid());
+        tmpfd.close();
+    }
+    let sizes = [0, 1, 2, 3, 5, 13, 23, 64, 128, 255, 4096, 4096 * 2];
+    for &size in &sizes {
+        let fd = AutoCloseFd::new(unsafe {
+            libc::open(filename.as_ptr(), O_RDWR | O_TRUNC | O_CREAT, 0o666)
+        });
+        assert!(fd.is_valid());
+        let mut input = WString::new();
+        for _i in 0..size {
+            input.push(random());
+        }
+
+        let amt = wwrite_to_fd(&input, fd.fd()).unwrap();
+        let narrow = wcs2string(&input);
+        assert_eq!(amt, narrow.len());
+
+        assert!(unsafe { libc::lseek(fd.fd(), 0, SEEK_SET) } >= 0);
+
+        let mut contents = vec![0u8; narrow.len()];
+        let read_amt = unsafe {
+            libc::read(
+                fd.fd(),
+                (&mut contents[0]) as *mut u8 as *mut c_void,
+                narrow.len(),
+            )
+        };
+        assert!(usize::try_from(read_amt).unwrap() == narrow.len());
+        assert_eq!(&contents, &narrow);
+    }
+    unsafe { libc::remove(filename.as_ptr()) };
+});