Merge pull request apollographql#309 from apollographql/lb/connectors-81

fix: make parent field suffix less ambiguous

Author: lennyburdette

apollo-router/src/plugins/connectors/join_spec_helpers.rs

@@ -512,6 +512,8 @@ pub(super) fn make_any_scalar() -> ExtendedType {
 
 use apollo_compiler::ast::Selection as GraphQLSelection;
 
+use super::request_inputs::PARENT_PREFIX;
+
 fn new_field(name: String, selection: Option<Vec<GraphQLSelection>>) -> GraphQLSelection {
     GraphQLSelection::Field(
         apollo_compiler::ast::Field {
@@ -538,8 +540,8 @@ pub(super) fn parameters_to_selection_set(paths: &Vec<String>) -> Vec<GraphQLSel
 
     for path in paths {
         let mut parts: Vec<&str> = path.split('.').collect();
-        // "this" is an alias, so we can ignore it
-        if parts.first() == Some(&"this") {
+        // "$this" is an alias, so we can ignore it
+        if parts.first() == Some(&PARENT_PREFIX) {
             parts = parts[1..].to_vec();
         }
 
@@ -598,8 +600,8 @@ mod tests {
                 "b.c".to_string(),
                 "b.d.e".to_string(),
                 "b.d.f".to_string(),
-                "this.g".to_string(),
-                "this.h.i".to_string()
+                "$this.g".to_string(),
+                "$this.h.i".to_string()
             ])),
             "id b { c d { e f } } g h { i }"
         )

apollo-router/src/plugins/connectors/mod.rs

@@ -8,6 +8,7 @@ pub(crate) mod subgraph_connector;
 mod supergraph;
 pub(crate) use supergraph::generate_connector_supergraph;
 mod http_json_transport;
+mod request_inputs;
 mod request_response;
 mod url_path_parser;
 

apollo-router/src/plugins/connectors/request_inputs.rs

@@ -0,0 +1,22 @@
+use serde_json_bytes::ByteString;
+use serde_json_bytes::Map;
+use serde_json_bytes::Value;
+
+pub(super) const PARENT_PREFIX: &str = "$this";
+
+#[derive(Debug, Default)]
+pub(super) struct RequestInputs {
+    pub(super) arguments: Map<ByteString, Value>,
+    pub(super) parent: Map<ByteString, Value>,
+}
+
+impl RequestInputs {
+    pub(super) fn merge(&self) -> Value {
+        let mut new = Map::new();
+        new.extend(self.parent.clone());
+        new.extend(self.arguments.clone());
+        // if parent types are shadowed by arguments, we can use `$this.` to access them
+        new.insert(PARENT_PREFIX, Value::Object(self.parent.clone()));
+        Value::Object(new)
+    }
+}

apollo-router/src/plugins/connectors/request_response.rs

@@ -5,12 +5,12 @@ use apollo_compiler::validation::Valid;
 use apollo_compiler::ExecutableDocument;
 use apollo_compiler::Schema;
 use serde_json_bytes::ByteString;
-use serde_json_bytes::Map;
 use serde_json_bytes::Value;
 
 use super::connector::ConnectorKind;
 use super::connector::ConnectorTransport;
 use super::http_json_transport::HttpJsonTransportError;
+use super::request_inputs::RequestInputs;
 use super::Connector;
 use crate::json_ext::Object;
 use crate::services::SubgraphRequest;
@@ -25,23 +25,6 @@ pub(crate) struct ResponseParams {
     key: ResponseKey,
 }
 
-#[derive(Debug, Default)]
-struct RequestInputs {
-    arguments: Map<ByteString, Value>,
-    parent: Map<ByteString, Value>,
-}
-
-impl RequestInputs {
-    fn merge(&self) -> Value {
-        let mut new = Map::new();
-        new.extend(self.parent.clone());
-        new.extend(self.arguments.clone());
-        // if parent types are shadowed by arguments, we can use `this.` to access them
-        new.insert("this", Value::Object(self.parent.clone()));
-        Value::Object(new)
-    }
-}
-
 #[derive(Clone, Debug)]
 enum ResponseKey {
     RootField {