Expose rust tracing instrumentation to javascript (#246)

crates/atlaspack_monitoring/src/tracer.rs

@@ -98,7 +98,9 @@ impl Tracer {
         None
       }
       TracerMode::Chrome => {
-        let (chrome_layer, guard) = tracing_chrome::ChromeLayerBuilder::new().build();
+        let (chrome_layer, guard) = tracing_chrome::ChromeLayerBuilder::new()
+          .include_args(true)
+          .build();
         tracing_subscriber::registry()
           .with(chrome_layer)
           .try_init()

crates/node-bindings/src/js_tracing.rs

@@ -0,0 +1,46 @@
+//! This module exposes the tracing API to JavaScript.
+
+use napi_derive::napi;
+use std::collections::HashMap;
+
+pub type SpanId = u32;
+
+#[napi]
+struct AtlaspackTracer {
+  current_spans: HashMap<SpanId, tracing::span::EnteredSpan>,
+  current_id: SpanId,
+}
+
+#[napi]
+impl AtlaspackTracer {
+  #[napi(constructor)]
+  pub fn new() -> Self {
+    Self {
+      current_spans: HashMap::new(),
+      current_id: 0,
+    }
+  }
+
+  #[napi]
+  pub fn enter(&mut self, label: String) -> SpanId {
+    let span = tracing::span!(tracing::Level::INFO, "js_span", label = label);
+
+    let id = self.current_id;
+    if self.current_id == u32::MAX {
+      self.current_id = 0;
+    } else {
+      self.current_id += 1;
+    }
+
+    self.current_spans.insert(id, span.entered());
+
+    id
+  }
+
+  #[napi]
+  pub fn exit(&mut self, id: SpanId) {
+    if let Some(span) = self.current_spans.remove(&id) {
+      drop(span);
+    }
+  }
+}

crates/node-bindings/src/lib.rs

@@ -19,6 +19,7 @@ mod fs_search;
 mod hash;
 #[cfg(not(target_arch = "wasm32"))]
 mod image;
+pub mod js_tracing;
 
 #[cfg(not(target_arch = "wasm32"))]
 mod atlaspack;

packages/core/core/src/Atlaspack.js

@@ -136,7 +136,8 @@ export default class Atlaspack {
       });
     } catch (e) {
       // Fallthrough
-      logger.warn(e);
+      // eslint-disable-next-line no-console
+      console.warn(e);
     }
 
     let resolvedOptions: AtlaspackOptions = await resolveOptions({