Make AppLauncher generic over ExecutionBackend instead of app

Author: sammuti

crates/tower-cmd/src/run.rs

@@ -5,9 +5,7 @@ use std::collections::HashMap;
 use std::path::PathBuf;
 use tower_api::models::Run;
 use tower_package::{Package, PackageSpec};
-use tower_runtime::{
-    execution::ExecutionHandle, local::LocalApp, AppLauncher, OutputReceiver, Status,
-};
+use tower_runtime::{execution::ExecutionHandle, AppLauncher, OutputReceiver, Status};
 use tower_telemetry::{debug, Context};
 
 use std::sync::Arc;
@@ -175,7 +173,7 @@ where
     // Create backend and launcher
     use tower_runtime::backends::local::LocalBackend;
     let backend = LocalBackend::new(config.cache_dir);
-    let mut launcher: AppLauncher<LocalApp> = AppLauncher::default();
+    let mut launcher: AppLauncher<LocalBackend> = AppLauncher::default();
 
     launcher
         .launch(

crates/tower-runtime/src/lib.rs

@@ -51,8 +51,6 @@ pub type OutputReceiver = UnboundedReceiver<Output>;
 pub type OutputSender = UnboundedSender<Output>;
 
 pub trait App: Send + Sync {
-    type Backend: ExecutionBackend;
-
     // start will start the process
     fn start(opts: StartOptions) -> impl Future<Output = Result<Self, Error>> + Send
     where
@@ -65,23 +63,20 @@ pub trait App: Send + Sync {
     fn status(&self) -> impl Future<Output = Result<Status, Error>> + Send;
 }
 
-pub struct AppLauncher<A: App> {
-    pub handle: Option<<A::Backend as ExecutionBackend>::Handle>,
+pub struct AppLauncher<B: ExecutionBackend> {
+    pub handle: Option<B::Handle>,
 }
 
-impl<A: App> std::default::Default for AppLauncher<A> {
+impl<B: ExecutionBackend> Default for AppLauncher<B> {
     fn default() -> Self {
         Self { handle: None }
     }
 }
 
-impl<A: App> AppLauncher<A>
-where
-    A::Backend: ExecutionBackend,
-{
+impl<B: ExecutionBackend> AppLauncher<B> {
     pub async fn launch(
         &mut self,
-        backend: A::Backend,
+        backend: B,
         ctx: tower_telemetry::Context,
         package: Package,
         environment: String,

crates/tower-runtime/src/local.rs

@@ -324,8 +324,6 @@ impl Drop for LocalApp {
 }
 
 impl App for LocalApp {
-    type Backend = crate::backends::local::LocalBackend;
-
     async fn start(opts: StartOptions) -> Result<Self, Error> {
         let terminator = CancellationToken::new();