Merge pull request #44 from fastly/pch/fix_40

Use wasmtime-wasi in async mode

cli/tests/sleep.rs

@@ -0,0 +1,20 @@
+mod common;
+use common::{Test, TestResult};
+use hyper::{body::to_bytes, StatusCode};
+/// Run a program that only sleeps. This exercises async functionality in wasi.
+/// Check that an empty response is sent downstream by default.
+///
+/// `sleep.wasm` is a guest program which sleeps for 100 milliseconds,then returns.
+#[tokio::test(flavor = "multi_thread")]
+async fn empty_ok_response_by_default_after_sleep() -> TestResult {
+    let resp = Test::using_fixture("sleep.wasm").against_empty().await;
+
+    assert_eq!(resp.status(), StatusCode::OK);
+    assert!(to_bytes(resp.into_body())
+        .await
+        .expect("can read body")
+        .to_vec()
+        .is_empty());
+
+    Ok(())
+}

lib/src/linking.rs

@@ -79,7 +79,7 @@ fn make_wasi_ctx(ctx: &ExecuteCtx, session: &Session) -> Result<WasiCtx, anyhow:
 }
 
 pub fn link_host_functions(linker: &mut Linker<WasmCtx>) -> Result<(), Error> {
-    wasmtime_wasi::add_to_linker(linker, WasmCtx::wasi)?;
+    wasmtime_wasi::tokio::add_to_linker(linker, WasmCtx::wasi)?;
     wiggle_abi::fastly_abi::add_to_linker(linker, WasmCtx::session)?;
     wiggle_abi::fastly_dictionary::add_to_linker(linker, WasmCtx::session)?;
     wiggle_abi::fastly_geo::add_to_linker(linker, WasmCtx::session)?;

test-fixtures/src/bin/sleep.rs

@@ -0,0 +1,3 @@
+fn main() {
+    std::thread::sleep(std::time::Duration::from_millis(100))
+}