tests: enable cat integration coverage on WASI

.github/workflows/wasi.yml

@@ -60,7 +60,7 @@ jobs:
         # Tests incompatible with WASI are annotated with
         # #[cfg_attr(wasi_runner, ignore)] in the test source files.
         # TODO: add integration tests for these tools as WASI support is extended:
-        #   arch b2sum cat cksum cp csplit date dir dircolors fmt join
+        #   arch b2sum cksum cp csplit date dir dircolors fmt join
         #   ls md5sum mkdir mv nproc pathchk pr printenv ptx pwd readlink
         #   realpath rm rmdir seq sha1sum sha224sum sha256sum sha384sum
         #   sha512sum shred sleep sort split tail touch tsort uname uniq
@@ -69,7 +69,7 @@ jobs:
         UUTESTS_WASM_RUNNER=wasmtime \
         cargo test --test tests -- \
           test_base32:: test_base64:: test_basenc:: test_basename:: \
-          test_comm:: test_cut:: test_dirname:: test_echo:: \
+          test_cat:: test_comm:: test_cut:: test_dirname:: test_echo:: \
           test_expand:: test_factor:: test_false:: test_fold:: \
           test_head:: test_link:: test_ln:: test_nl:: test_numfmt:: \
           test_od:: test_paste:: test_printf:: test_shuf:: test_sum:: \

src/uu/cat/src/platform/mod.rs

@@ -9,7 +9,11 @@ pub use self::unix::is_safe_overwrite;
 #[cfg(windows)]
 pub use self::windows::is_safe_overwrite;
 
-// WASI: no fstat-based device/inode checks available; assume safe.
+// WASI: when stdout is inherited from a host file descriptor, wasmtime
+// reports its fstat as all-zero (st_dev == st_ino == 0), so the dev/inode
+// comparison against any input file descriptor can never match. There is
+// no reliable way to detect unsafe overwrite here; assume safe rather than
+// risk a spurious error.
 #[cfg(target_os = "wasi")]
 pub fn is_safe_overwrite<I, O>(_input: &I, _output: &O) -> bool {
     true

tests/by-util/test_cat.rs

@@ -2,7 +2,7 @@
 //
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
-// spell-checker:ignore NOFILE nonewline cmdline
+// spell-checker:ignore NOFILE nonewline cmdline setrlimit ELOOP
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use rlimit::Resource;
@@ -87,6 +87,7 @@ fn test_no_options_big_input() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: no FIFO/mkfifo support")]
 fn test_fifo_symlink() {
     use std::io::Write;
     use std::thread;
@@ -121,6 +122,7 @@ fn test_fifo_symlink() {
 // TODO(#7542): Re-enable on Android once we figure out why setting limit is broken.
 // #[cfg(any(target_os = "linux", target_os = "android"))]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI: rlimit/setrlimit not supported")]
 fn test_closes_file_descriptors() {
     // Each file creates a pipe, which has two file descriptors.
     // If they are not closed then five is certainly too many.
@@ -138,6 +140,7 @@ fn test_closes_file_descriptors() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: no pipe/signal support")]
 fn test_broken_pipe() {
     let mut cmd = new_ucmd!();
     let mut child = cmd
@@ -514,6 +517,7 @@ fn test_squeeze_blank_before_numbering() {
 /// This tests reading from Unix character devices
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_dev_random() {
     #[cfg(any(target_os = "linux", target_os = "android"))]
     const DEV_RANDOM: &str = "/dev/urandom";
@@ -544,6 +548,7 @@ fn test_dev_random() {
 /// Wikipedia says there is support on Linux, FreeBSD, and `NetBSD`.
 #[test]
 #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "netbsd"))]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_dev_full() {
     let mut proc = new_ucmd!()
         .set_stdout(Stdio::piped())
@@ -559,6 +564,7 @@ fn test_dev_full() {
 
 #[test]
 #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "netbsd"))]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_dev_full_show_all() {
     let buf_len = 2048;
     let mut proc = new_ucmd!()
@@ -581,6 +587,7 @@ fn test_dev_full_show_all() {
 // without additional flush output gets reversed.
 #[test]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI sandbox: host paths not visible")]
 fn test_write_fast_fallthrough_uses_flush() {
     const PROC_INIT_CMDLINE: &str = "/proc/1/cmdline";
     let cmdline = read_to_string(PROC_INIT_CMDLINE).unwrap();
@@ -593,6 +600,7 @@ fn test_write_fast_fallthrough_uses_flush() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: no Unix domain socket support")]
 fn test_domain_socket() {
     use std::os::unix::net::UnixListener;
 
@@ -618,10 +626,11 @@ fn test_write_to_self_empty() {
         .open(&file_path)
         .unwrap();
 
-    s.ucmd().set_stdout(file).arg(&file_path).succeeds();
+    s.ucmd().set_stdout(file).arg("file.txt").succeeds();
 }
 
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI: cannot detect unsafe overwrite")]
 fn test_write_to_self() {
     let s = TestScenario::new(util_name!());
     let file_path = s.fixtures.plus("first_file");
@@ -678,6 +687,7 @@ fn test_successful_write_to_read_write_self() {
 ///
 /// `cat fx fx3 1<>fx3`
 #[test]
+#[cfg_attr(wasi_runner, ignore = "WASI: cannot detect unsafe overwrite")]
 fn test_failed_write_to_read_write_self() {
     let (at, mut ucmd) = at_and_ucmd!();
     at.write("fx", "g");
@@ -703,6 +713,10 @@ fn test_failed_write_to_read_write_self() {
 #[test]
 #[cfg(unix)]
 #[cfg(not(target_os = "openbsd"))]
+#[cfg_attr(
+    wasi_runner,
+    ignore = "WASI: symlink loop traversal does not surface ELOOP ('Too many levels of symbolic links')"
+)]
 fn test_error_loop() {
     let (at, mut ucmd) = at_and_ucmd!();
     at.symlink_file("2", "1");
@@ -726,6 +740,7 @@ fn test_u_ignored() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: errno/error-message mismatches")]
 fn test_write_fast_read_error() {
     use std::os::unix::fs::PermissionsExt;
 
@@ -746,6 +761,7 @@ fn test_write_fast_read_error() {
 
 #[test]
 #[cfg(target_os = "linux")]
+#[cfg_attr(wasi_runner, ignore = "WASI: argv/filenames must be valid UTF-8")]
 fn test_cat_non_utf8_paths() {
     use std::ffi::OsStr;
     use std::os::unix::ffi::OsStrExt;
@@ -770,6 +786,7 @@ fn test_cat_non_utf8_paths() {
 
 #[test]
 #[cfg(unix)]
+#[cfg_attr(wasi_runner, ignore = "WASI: cannot detect unsafe overwrite")]
 fn test_appending_same_input_output() {
     let (at, mut ucmd) = at_and_ucmd!();