Specify extra runtime flags in tests, not CI

This enables keeping runtime/wasmtime flags scoped to just one test
rather than requiring it for all tests. For example
`-Wcomponent-model-threading` is scoped to just one test right now.

Author: alexcrichton

.github/workflows/main.yml

@@ -160,8 +160,7 @@ jobs:
     - run: |
         cargo run test --languages rust,c,go tests/runtime-async \
           --artifacts target/artifacts \
-          --rust-wit-bindgen-path ./crates/guest-rust \
-          --runner "wasmtime -W component-model-async -W component-model-threading -W component-model-async-stackful"
+          --rust-wit-bindgen-path ./crates/guest-rust
 
   test_unit:
     name: Crate Unit Tests

crates/test/src/config.rs

@@ -64,6 +64,11 @@ pub struct RuntimeTestConfig<T = HashMap<String, toml::Value>> {
     #[serde(default)]
     pub args: StringList,
 
+    /// Extra command line arguments to to pass to Wasmtime, such as enabling
+    /// extra wasm features.
+    #[serde(default)]
+    pub wasmtime_flags: StringList,
+
     /// Language-specific configuration
     //
     // Note that this is an `Option<T>` where `T` defaults to a catch-all hash

crates/test/src/lib.rs

@@ -193,6 +193,9 @@ struct Component {
 
     /// The contents of the test file itself.
     lang_config: Option<HashMap<String, toml::Value>>,
+
+    /// Runtime flags to wasmtime.
+    wasmtime_flags: config::StringList,
 }
 
 #[derive(Clone)]
@@ -467,6 +470,7 @@ impl Runner {
             kind,
             contents,
             lang_config: config.lang,
+            wasmtime_flags: config.wasmtime_flags,
         })
     }
 
@@ -911,7 +915,17 @@ impl Runner {
         let composed_wasm = dst.join(filename);
         write_if_different(&composed_wasm, &composed)?;
 
-        self.run_command(self.test_runner.command().arg(&composed_wasm))?;
+        let mut cmd = self.test_runner.command();
+        for component in [runner]
+            .into_iter()
+            .chain(test_components.iter().map(|(c, _)| *c))
+        {
+            for flag in Vec::from(component.wasmtime_flags.clone()) {
+                cmd.arg(flag);
+            }
+        }
+        cmd.arg(&composed_wasm);
+        self.run_command(&mut cmd)?;
         Ok(())
     }
 

tests/runtime-async/async/cancel-import/runner.c

@@ -1,4 +1,5 @@
 //@ args = '--rename my:test/i=test --async=-run'
+//@ wasmtime-flags = '-Wcomponent-model-async'
 
 #include <assert.h>
 #include <runner.h>

tests/runtime-async/async/cancel-import/runner.rs

@@ -1,3 +1,5 @@
+//@ wasmtime-flags = '-Wcomponent-model-async'
+
 include!(env!("BINDINGS"));
 
 use crate::my::test::i::*;

tests/runtime-async/async/future-cancel-read/runner.c

@@ -1,4 +1,5 @@
 //@ args = '--rename my:test/i=test --async=-run'
+//@ wasmtime-flags = '-Wcomponent-model-async'
 
 #include <assert.h>
 #include <runner.h>

tests/runtime-async/async/future-cancel-read/runner.rs

@@ -1,3 +1,5 @@
+//@ wasmtime-flags = '-Wcomponent-model-async'
+
 include!(env!("BINDINGS"));
 
 use crate::my::test::i::*;

tests/runtime-async/async/future-cancel-write-then-read/runner.rs

@@ -1,3 +1,5 @@
+//@ wasmtime-flags = '-Wcomponent-model-async'
+
 include!(env!("BINDINGS"));
 
 use crate::a::b::the_test::f;

tests/runtime-async/async/future-cancel-write/runner.c

@@ -1,4 +1,5 @@
 //@ args = '--rename my:test/i=test --async=-run'
+//@ wasmtime-flags = '-Wcomponent-model-async'
 
 #include <assert.h>
 #include <runner.h>

tests/runtime-async/async/future-cancel-write/runner.rs

@@ -1,3 +1,5 @@
+//@ wasmtime-flags = '-Wcomponent-model-async'
+
 include!(env!("BINDINGS"));
 
 use crate::my::test::i::{read_and_drop, take_then_drop};