Allow rover dev to utilise watching again

src/command/dev/do_dev.rs

@@ -45,6 +45,7 @@ impl Dev {
                 .unwrap_or(FederationVersion::LatestFedTwo),
             client_config.clone(),
             &self.opts.plugin_opts.profile,
+            false,
         )
         .await?;
 

src/command/supergraph/compose/do_compose.rs

@@ -119,6 +119,7 @@ impl Compose {
             &self.opts.federation_version.clone().unwrap_or(LatestFedTwo),
             client_config.clone(),
             &self.opts.plugin_opts.profile,
+            true,
         )
         .await?
         // WARNING: remove this unwrap

src/utils/supergraph_config.rs

@@ -63,6 +63,7 @@ pub async fn get_supergraph_config(
     federation_version: &FederationVersion,
     client_config: StudioClientConfig,
     profile_opt: &ProfileOpt,
+    create_static_config: bool,
 ) -> Result<Option<SupergraphConfig>, RoverError> {
     // Read in Remote subgraphs
     let remote_subgraphs = match graph_ref {
@@ -75,11 +76,23 @@ pub async fn get_supergraph_config(
         }
         None => None,
     };
-
-    // Read in Local Supergraph Config
     let supergraph_config = if let Some(file_descriptor) = &supergraph_config_path {
-        eprintln!("resolving SDL for subgraphs defined in supergraph schema file",);
-        Some(resolve_supergraph_yaml(file_descriptor, client_config, profile_opt).await?)
+        // Depending on the context we might want two slightly different kinds of SupergraphConfig.
+        if create_static_config {
+            // In this branch we get a completely resolved config, so all the references in it are
+            // resolved to a concrete SDL that could be printed out to a user. This is what
+            // `supergraph compose` uses.
+            Some(resolve_supergraph_yaml(file_descriptor, client_config, profile_opt).await?)
+        } else {
+            // Alternatively, we might actually want a more dynamic object so that we can
+            // set up watchers on the subgraph sources. This branch is what `rover dev` uses.
+            // So we run the `expand` function only to hydrate the YAML into a series of objects,
+            // but we don't need to completely resolve all of those objects.
+            let config = file_descriptor
+                .read_file_descriptor("supergraph config", &mut std::io::stdin())
+                .and_then(|contents| expand_supergraph_yaml(&contents))?;
+            Some(config)
+        }
     } else {
         None
     };
@@ -330,6 +343,7 @@ mod test_get_supergraph_config {
                 latest_fed2_version,
                 studio_client_config,
                 &profile_opt,
+                true,
             )
             .await
             .expect("Could not construct SupergraphConfig")
@@ -340,6 +354,7 @@ mod test_get_supergraph_config {
                 latest_fed2_version,
                 studio_client_config,
                 &profile_opt,
+                true,
             )
             .await
             .expect("Could not construct SupergraphConfig")