Skip load_instance_pre for components not referenced by the trigger

This allows the manifest to contain components which exist only to be used in composition and do not necessarily comply with the Spin world - albeit more important for future middleware-style projects than for current import-style dependencies.

Signed-off-by: itowlson <[email protected]>

Author: itowlson

crates/factors-executor/src/lib.rs

@@ -53,6 +53,7 @@ impl<T: RuntimeFactors, U: Send + 'static> FactorsExecutor<T, U> {
         app: App,
         runtime_config: T::RuntimeConfig,
         component_loader: &impl ComponentLoader<T, U>,
+        trigger_type: Option<&str>,
     ) -> anyhow::Result<FactorsExecutorApp<T, U>> {
         let configured_app = self
             .factors
@@ -63,7 +64,14 @@ impl<T: RuntimeFactors, U: Send + 'static> FactorsExecutor<T, U> {
             hooks.configure_app(&configured_app).await?;
         }
 
-        let components = configured_app.app().components();
+        let components = match trigger_type {
+            Some(trigger_type) => configured_app
+                .app()
+                .triggers_with_type(trigger_type)
+                .filter_map(|t| t.component().ok())
+                .collect::<Vec<_>>(),
+            None => configured_app.app().components().collect(),
+        };
         let mut component_instance_pres = HashMap::with_capacity(components.len());
 
         for component in components {
@@ -334,7 +342,7 @@ mod tests {
         let executor = Arc::new(FactorsExecutor::new(engine_builder, env.factors)?);
 
         let factors_app = executor
-            .load_app(app, Default::default(), &DummyComponentLoader)
+            .load_app(app, Default::default(), &DummyComponentLoader, None)
             .await?;
 
         let mut instance_builder = factors_app.prepare("empty")?;

crates/trigger/src/cli.rs

@@ -341,7 +341,7 @@ impl<T: Trigger<B::Factors>, B: RuntimeFactorsBuilder> TriggerAppBuilder<T, B> {
         let configured_app = {
             let _sloth_guard = warn_if_wasm_build_slothful();
             executor
-                .load_app(app, runtime_config.into(), loader)
+                .load_app(app, runtime_config.into(), loader, Some(T::TYPE))
                 .await?
         };
 

examples/spin-timer/Cargo.lock

@@ -1533,6 +1533,29 @@ route = "/..."
         Ok(())
     }
 
+    #[test]
+    fn test_does_not_load_triggerless_component() -> anyhow::Result<()> {
+        run_test(
+            "unsupported-import-unused",
+            SpinConfig {
+                binary_path: spin_binary(),
+                spin_up_args: Vec::new(),
+                app_type: SpinAppType::Http,
+            },
+            ServicesConfig::none(),
+            move |env| {
+                let spin = env.runtime_mut();
+                assert_spin_request(
+                    spin,
+                    Request::full(Method::Get, "/", &[], Some("")),
+                    Response::new_with_body(200, "Hello World!\n"),
+                )?;
+                Ok(())
+            },
+        )?;
+        Ok(())
+    }
+
     #[test]
     fn test_outbound_post() -> anyhow::Result<()> {
         run_test(