stream wit definition eliminates stream-error

crates/wasi/src/preview2/command.rs

@@ -6,7 +6,6 @@ wasmtime::component::bindgen!({
     async: true,
     trappable_error_type: {
         "wasi:filesystem/types"::"error-code": Error,
-        "wasi:io/streams"::"stream-error": Error,
     },
     with: {
        "wasi:filesystem/types": crate::preview2::bindings::filesystem::types,
@@ -61,7 +60,6 @@ pub mod sync {
         async: false,
         trappable_error_type: {
             "wasi:filesystem/types"::"error-code": Error,
-            "wasi:io/streams"::"stream-error": Error,
         },
         with: {
            "wasi:filesystem/types": crate::preview2::bindings::sync_io::filesystem::types,

crates/wasi/src/preview2/filesystem.rs

@@ -1,4 +1,4 @@
-use crate::preview2::{StreamState, Table, TableError};
+use crate::preview2::{StreamRuntimeError, StreamState, Table, TableError};
 use bytes::{Bytes, BytesMut};
 use std::sync::Arc;
 
@@ -152,24 +152,20 @@ impl FileInputStream {
     }
 }
 
-pub(crate) fn read_result(
-    r: Result<usize, std::io::Error>,
-) -> Result<(usize, StreamState), std::io::Error> {
+fn read_result(r: Result<usize, std::io::Error>) -> Result<(usize, StreamState), anyhow::Error> {
     match r {
         Ok(0) => Ok((0, StreamState::Closed)),
         Ok(n) => Ok((n, StreamState::Open)),
         Err(e) if e.kind() == std::io::ErrorKind::Interrupted => Ok((0, StreamState::Open)),
-        Err(e) => Err(e),
+        Err(e) => Err(StreamRuntimeError::from(anyhow::anyhow!(e)).into()),
     }
 }
 
-pub(crate) fn write_result(
-    r: Result<usize, std::io::Error>,
-) -> Result<(usize, StreamState), std::io::Error> {
+fn write_result(r: Result<usize, std::io::Error>) -> Result<(usize, StreamState), anyhow::Error> {
     match r {
         Ok(0) => Ok((0, StreamState::Closed)),
         Ok(n) => Ok((n, StreamState::Open)),
-        Err(e) => Err(e),
+        Err(e) => Err(StreamRuntimeError::from(anyhow::anyhow!(e)).into()),
     }
 }
 

crates/wasi/src/preview2/host/filesystem.rs

@@ -209,15 +209,18 @@ impl<T: WasiView> types::Host for T {
             })
             .await;
 
-        let (bytes_read, state) = crate::preview2::filesystem::read_result(r)?;
+        let (bytes_read, state) = match r? {
+            0 => (0, true),
+            n => (n, false),
+        };
 
         buffer.truncate(
             bytes_read
                 .try_into()
                 .expect("bytes read into memory as u64 fits in usize"),
         );
 
-        Ok((buffer, state.is_closed()))
+        Ok((buffer, state))
     }
 
     async fn write(