Support plugins with imported functions (#881)

* Support plugins with imported functions

* Move define_unknown_imports_as_trap before instantiate

* Also handle static case in test runner

* Exclude test-plugin from unit testing (it has no tests)

.github/workflows/ci.yml

@@ -57,7 +57,7 @@ jobs:
       - name: Test
         env:
           CARGO_TARGET_WASM32_WASIP1_RUNNER: wasmtime --dir=.
-        run: cargo hack test --target=wasm32-wasip1 --workspace --exclude=javy-cli --exclude=javy-runner --each-feature -- --nocapture
+        run: cargo hack test --target=wasm32-wasip1 --workspace --exclude=javy-cli --exclude=javy-runner --exclude=javy-test-plugin --each-feature -- --nocapture
 
       - name: Test Runner
         run: cargo test --package=javy-runner

crates/cli/src/bytecode.rs

@@ -21,6 +21,7 @@ fn create_wasm_env(plugin: &Plugin) -> Result<(Store<WasiCtx>, Instance, Memory)
         &mut linker,
         |s| s,
     )?;
+    linker.define_unknown_imports_as_traps(&module)?;
     let wasi = WasiCtxBuilder::new().inherit_stderr().build();
     let mut store = Store::new(&engine, wasi);
     let instance = linker.instantiate(store.as_context_mut(), &module)?;

crates/runner/src/lib.rs

@@ -669,12 +669,16 @@ impl Runner {
 
         if let Some((name, bytes)) = &self.preload {
             let module = Module::from_binary(self.linker.engine(), bytes)?;
+            // Allow unknown imports for dynamically linked `test-plugin`.
+            self.linker.define_unknown_imports_as_traps(&module)?;
             let instance = self.linker.instantiate(store.as_context_mut(), &module)?;
             self.linker.allow_shadowing(true);
             self.linker
                 .instance(store.as_context_mut(), name, instance)?;
         }
 
+        // Allow unknown imports for statically linked `test-plugin`.
+        self.linker.define_unknown_imports_as_traps(&module)?;
         let instance = self.linker.instantiate(store.as_context_mut(), &module)?;
         let run = instance.get_typed_func::<(), ()>(store.as_context_mut(), func)?;
 

crates/test-plugin/src/lib.rs

@@ -1,18 +1,25 @@
 //! Plugin used for testing. We need a plugin with slightly different behavior
 //! to validate a plugin is actually used when it should be.
 
-use javy_plugin_api::{import_namespace, Config};
+use javy_plugin_api::{import_namespace, javy::quickjs::prelude::Func, Config};
 
 import_namespace!("test_plugin");
 
+#[link(wasm_import_module = "some_host")]
+extern "C" {
+    fn imported_function();
+}
+
 #[export_name = "initialize_runtime"]
 pub extern "C" fn initialize_runtime() {
     let config = Config::default();
     javy_plugin_api::initialize_runtime(config, |runtime| {
-        runtime
-            .context()
-            .with(|ctx| ctx.globals().set("plugin", true))
-            .unwrap();
+        runtime.context().with(|ctx| {
+            ctx.globals().set("plugin", true).unwrap();
+            ctx.globals()
+                .set("func", Func::from(|| unsafe { imported_function() }))
+                .unwrap();
+        });
         runtime
     })
     .unwrap();