activate defer support in introspection

NEXT_CHANGELOG.md

@@ -472,6 +472,12 @@ will create a separate response for each element of the array.
 
 By [@Geal](https://github.com/Geal) in https://github.com/apollographql/router/pull/1529
 
+### Activate defer support in introspection ([PR #1557](https://github.com/apollographql/router/pull/1557))
+
+Introspection queries will now see the `@defer` directive if it was activated in the configuration file.
+
+By [@Geal](https://github.com/Geal) in https://github.com/apollographql/router/pull/1557
+
 ## 🛠 Maintenance
 
 ### Display licenses.html diff in CI if the check failed ([#1524](https://github.com/apollographql/router/issues/1524))

apollo-router/Cargo.toml

@@ -119,7 +119,7 @@ reqwest = { version = "0.11.11", default-features = false, features = [
     "json",
     "stream",
 ] }
-router-bridge = { git = "https://github.com/apollographql/federation-rs.git", tag = "defer-alpha1" }
+router-bridge = { git = "https://github.com/apollographql/federation-rs.git", tag = "defer-alpha3" }
 schemars = { version = "0.8.10", features = ["url"] }
 sha2 = "0.10.2"
 serde = { version = "1.0.143", features = ["derive", "rc"] }

apollo-router/src/introspection.rs

@@ -3,31 +3,39 @@ use std::collections::HashMap;
 
 use router_bridge::introspect;
 use router_bridge::introspect::IntrospectionError;
+use router_bridge::planner::DeferStreamSupport;
+use router_bridge::planner::QueryPlannerConfig;
 
 use crate::cache::storage::CacheStorage;
 use crate::graphql::Response;
+use crate::Configuration;
 
 const DEFAULT_INTROSPECTION_CACHE_CAPACITY: usize = 5;
 
 /// A cache containing our well known introspection queries.
 pub(crate) struct Introspection {
     cache: CacheStorage<String, Response>,
+    defer_support: bool,
 }
 
 impl Introspection {
-    pub(crate) async fn with_capacity(capacity: usize) -> Self {
+    pub(crate) async fn with_capacity(configuration: &Configuration, capacity: usize) -> Self {
         Self {
             cache: CacheStorage::new(capacity).await,
+            defer_support: configuration.server.experimental_defer_support,
         }
     }
 
-    pub(crate) async fn new() -> Self {
-        Self::with_capacity(DEFAULT_INTROSPECTION_CACHE_CAPACITY).await
+    pub(crate) async fn new(configuration: &Configuration) -> Self {
+        Self::with_capacity(configuration, DEFAULT_INTROSPECTION_CACHE_CAPACITY).await
     }
 
     #[cfg(test)]
-    pub(crate) async fn from_cache(cache: HashMap<String, Response>) -> Self {
-        let this = Self::with_capacity(cache.len()).await;
+    pub(crate) async fn from_cache(
+        configuration: &Configuration,
+        cache: HashMap<String, Response>,
+    ) -> Self {
+        let this = Self::with_capacity(configuration, cache.len()).await;
 
         for (query, response) in cache.into_iter() {
             this.cache.insert(query, response).await;
@@ -46,10 +54,18 @@ impl Introspection {
         }
 
         // Do the introspection query and cache it
-        let mut response = introspect::batch_introspect(schema_sdl, vec![query.to_owned()])
-            .map_err(|err| IntrospectionError {
-                message: format!("Deno runtime error: {:?}", err).into(),
-            })??;
+        let mut response = introspect::batch_introspect(
+            schema_sdl,
+            vec![query.to_owned()],
+            QueryPlannerConfig {
+                defer_stream_support: Some(DeferStreamSupport {
+                    enable_defer: Some(self.defer_support),
+                }),
+            },
+        )
+        .map_err(|err| IntrospectionError {
+            message: format!("Deno runtime error: {:?}", err).into(),
+        })??;
         let introspection_result = response
             .pop()
             .ok_or_else(|| IntrospectionError {
@@ -89,7 +105,7 @@ mod introspection_tests {
             .iter()
             .cloned()
             .collect();
-        let introspection = Introspection::from_cache(cache).await;
+        let introspection = Introspection::from_cache(&Configuration::default(), cache).await;
 
         assert_eq!(
             expected_data,

apollo-router/src/query_planner/bridge_query_planner.rs

@@ -201,7 +201,9 @@ mod tests {
     async fn test_plan() {
         let planner = BridgeQueryPlanner::new(
             Arc::new(example_schema()),
-            Some(Arc::new(Introspection::new().await)),
+            Some(Arc::new(
+                Introspection::new(&Configuration::default()).await,
+            )),
             Default::default(),
         )
         .await
@@ -228,7 +230,9 @@ mod tests {
     async fn test_plan_invalid_query() {
         let planner = BridgeQueryPlanner::new(
             Arc::new(example_schema()),
-            Some(Arc::new(Introspection::new().await)),
+            Some(Arc::new(
+                Introspection::new(&Configuration::default()).await,
+            )),
             Default::default(),
         )
         .await
@@ -272,7 +276,9 @@ mod tests {
     async fn empty_query_plan_should_be_a_planner_error() {
         let err = BridgeQueryPlanner::new(
             Arc::new(example_schema()),
-            Some(Arc::new(Introspection::new().await)),
+            Some(Arc::new(
+                Introspection::new(&Configuration::default()).await,
+            )),
             Default::default(),
         )
         .await
@@ -306,7 +312,9 @@ mod tests {
     async fn test_plan_error() {
         let planner = BridgeQueryPlanner::new(
             Arc::new(example_schema()),
-            Some(Arc::new(Introspection::new().await)),
+            Some(Arc::new(
+                Introspection::new(&Configuration::default()).await,
+            )),
             Default::default(),
         )
         .await

apollo-router/src/services/supergraph_service.rs

@@ -349,7 +349,7 @@ impl PluggableSupergraphServiceBuilder {
             .unwrap_or(100);
 
         let introspection = if configuration.server.introspection {
-            Some(Arc::new(Introspection::new().await))
+            Some(Arc::new(Introspection::new(&configuration).await))
         } else {
             None
         };