wasi:[email protected]: Add tests for is-same-object

Author: wingo

tests/rust/wasm32-wasip3/src/bin/filesystem-is-same-object.json

@@ -0,0 +1,3 @@
+{
+    "dirs": ["fs-tests.dir"]
+}

tests/rust/wasm32-wasip3/src/bin/filesystem-is-same-object.rs

@@ -0,0 +1,81 @@
+use std::process;
+extern crate wit_bindgen;
+
+wit_bindgen::generate!({
+    inline: r"
+  package test:test;
+
+  world test {
+      include wasi:filesystem/[email protected];
+      include wasi:cli/[email protected];
+  }
+",
+    additional_derives: [PartialEq, Eq, Hash, Clone],
+    // Work around https://github.com/bytecodealliance/wasm-tools/issues/2285.
+    features:["clocks-timezone"],
+    generate_all
+});
+
+use wasi::filesystem::types::Descriptor;
+use wasi::filesystem::types::{DescriptorFlags, OpenFlags, PathFlags};
+
+async fn test_is_same_object(dir: &Descriptor) {
+    let afd = dir
+        .open_at(
+            PathFlags::empty(),
+            "a.txt".to_string(),
+            OpenFlags::empty(),
+            DescriptorFlags::READ,
+        )
+        .await
+        .unwrap();
+    let bfd = dir
+        .open_at(
+            PathFlags::empty(),
+            "b.txt".to_string(),
+            OpenFlags::empty(),
+            DescriptorFlags::READ,
+        )
+        .await
+        .unwrap();
+
+    // is-same-object: async func(other: borrow<descriptor>) -> bool;
+    assert!(dir.is_same_object(dir).await);
+    {
+        let other = dir
+            .open_at(
+                PathFlags::empty(),
+                ".".to_string(),
+                OpenFlags::empty(),
+                DescriptorFlags::READ,
+            )
+            .await
+            .unwrap();
+        assert!(dir.is_same_object(&other).await);
+    }
+    assert!(!dir.is_same_object(&afd).await);
+    assert!(afd.is_same_object(&afd).await);
+    assert!(!afd.is_same_object(&bfd).await);
+    assert!(bfd.is_same_object(&bfd).await);
+}
+
+struct Component;
+export!(Component);
+impl exports::wasi::cli::run::Guest for Component {
+    async fn run() -> Result<(), ()> {
+        match &wasi::filesystem::preopens::get_directories()[..] {
+            [(dir, dirname)] if dirname == "fs-tests.dir" => {
+                test_is_same_object(dir).await;
+            }
+            [..] => {
+                eprintln!("usage: run with one open dir named 'fs-tests.dir'");
+                process::exit(1)
+            }
+        };
+        Ok(())
+    }
+}
+
+fn main() {
+    unreachable!("main is a stub");
+}