Added hot reload implementation, blocked by tide SSE

Cargo.toml

@@ -21,6 +21,7 @@ async-process = "0.1.1"
 async-std = { version="1.6.3", features=["attributes", "unstable"] }
 cargo_metadata = "0.11.3"
 console = "0.13.0"
+crossbeam-channel = "0.5"
 dunce = "1.0.1"
 envy = "0.4.1"
 fs_extra = "1.2.0"
@@ -33,6 +34,7 @@ open = "1.4.0"
 sass-rs = "0.2.2"
 seahash = "4.0.1"
 serde = { version="1", features=["derive"] }
+serde_json = "1.0.59"
 structopt = "0.3.18"
 structopt-derive = "0.4.11"
 surf = "2.0.0"

src/build.rs

@@ -5,8 +5,10 @@ use std::sync::Arc;
 
 use anyhow::Result;
 use async_std::fs;
+use crossbeam_channel::Sender as CrossbeamSender;
 use futures::channel::mpsc::Sender;
 use indicatif::ProgressBar;
+use serde::Serialize;
 
 use crate::common::{BUILDING, ERROR, SUCCESS};
 use crate::config::RtcBuild;
@@ -25,24 +27,31 @@ pub struct BuildSystem {
     html_pipeline: Arc<HtmlPipeline>,
     /// The build system progress bar for displaying the state of the build system overall.
     progress: ProgressBar,
+    /// An optional channel to send build events to
+    build_event_tx: Option<CrossbeamSender<BuildEvent>>,
 }
 
 impl BuildSystem {
     /// Create a new instance from the raw components.
     ///
     /// Reducing the number of assumptions here should help us to stay flexible when adding new
     /// commands, rafctoring and the like.
-    pub async fn new(cfg: Arc<RtcBuild>, progress: ProgressBar, ignore_chan: Option<Sender<PathBuf>>) -> Result<Self> {
+    pub async fn new(
+        cfg: Arc<RtcBuild>, progress: ProgressBar, ignore_chan: Option<Sender<PathBuf>>, build_event_tx: Option<CrossbeamSender<BuildEvent>>,
+    ) -> Result<Self> {
         let html_pipeline = Arc::new(HtmlPipeline::new(cfg.clone(), progress.clone(), ignore_chan)?);
         Ok(Self {
             cfg,
             html_pipeline,
             progress,
+            build_event_tx,
         })
     }
 
     /// Build the application described in the given build data.
     pub async fn build(&mut self) -> Result<()> {
+        self.send_build_event(|| BuildEvent::Building);
+
         self.progress.reset();
         self.progress.enable_steady_tick(100);
         self.progress.set_prefix(&format!("{}", BUILDING));
@@ -52,18 +61,28 @@ impl BuildSystem {
         self.progress.set_position(0);
         match res {
             Ok(_) => {
+                self.send_build_event(|| BuildEvent::Success);
+
                 self.progress.set_prefix(&format!("{}", SUCCESS));
                 self.progress.finish_with_message("success");
                 Ok(())
             }
             Err(err) => {
+                self.send_build_event(|| BuildEvent::Error(err.to_string()));
+
                 self.progress.set_prefix(&format!("{}", ERROR));
                 self.progress.finish_with_message("error");
                 Err(err)
             }
         }
     }
 
+    fn send_build_event<F: FnOnce() -> BuildEvent>(&mut self, event_builder: F) {
+        if let Some(receiver) = &mut self.build_event_tx {
+            let _ = receiver.send(event_builder());
+        }
+    }
+
     async fn do_build(&mut self) -> Result<()> {
         // TODO: delete the contents of the `dist/.current` dir (currently in flight elsewhere).
 
@@ -76,3 +95,11 @@ impl BuildSystem {
         Ok(())
     }
 }
+
+#[derive(Serialize)]
+#[serde(tag = "type")]
+pub enum BuildEvent {
+    Building,
+    Success,
+    Error(String),
+}

src/cmd/build.rs

@@ -18,7 +18,7 @@ pub struct Build {
 impl Build {
     pub async fn run(self, config: Option<PathBuf>) -> Result<()> {
         let cfg = ConfigOpts::rtc_build(self.build, config).await?;
-        let mut system = BuildSystem::new(cfg, spinner(), None).await?;
+        let mut system = BuildSystem::new(cfg, spinner(), None, None).await?;
         system.build().await?;
         Ok(())
     }