JSONSelection refactoring, $variable syntax, and an extensive new README.md

apollo-federation/src/sources/connect/federated_query_graph/builder.rs

@@ -14,10 +14,10 @@ use crate::sources::connect::federated_query_graph::ConcreteNode;
 use crate::sources::connect::federated_query_graph::EnumNode;
 use crate::sources::connect::federated_query_graph::ScalarNode;
 use crate::sources::connect::federated_query_graph::SourceEnteringEdge;
+use crate::sources::connect::json_selection::JSONSelection;
+use crate::sources::connect::json_selection::Key;
+use crate::sources::connect::json_selection::SubSelection;
 use crate::sources::connect::models::Connector;
-use crate::sources::connect::selection_parser::Property;
-use crate::sources::connect::selection_parser::SubSelection;
-use crate::sources::connect::Selection;
 use crate::sources::source::federated_query_graph::builder::FederatedQueryGraphBuilderApi;
 use crate::sources::source::SourceId;
 use crate::ValidFederationSubgraph;
@@ -106,7 +106,7 @@ impl FederatedQueryGraphBuilderApi for FederatedQueryGraphBuilder {
 /// This method creates nodes from selection parameters of a field decorated by
 /// a connect directive, making sure to reuse nodes if possible.
 fn process_selection(
-    selection: Selection,
+    selection: JSONSelection,
     field_output_type_pos: TypeDefinitionPosition,
     subgraph_schema: &ValidFederationSchema,
     builder: &mut impl IntraSourceQueryGraphBuilderApi,
@@ -137,7 +137,7 @@ fn process_selection(
 
     // If we aren't a custom scalar, then look at the selection to see what to attempt
     match selection {
-        Selection::Path(path) => match field_output_type_pos {
+        JSONSelection::Path(path) => match field_output_type_pos {
             TypeDefinitionPosition::Enum(enum_type) => {
                 // Create the node for this enum
                 builder.add_enum_node(
@@ -179,7 +179,7 @@ fn process_selection(
                 )
             }
         },
-        Selection::Named(sub) => {
+        JSONSelection::Named(sub) => {
             // Make sure that we aren't selecting sub fields from simple types
             if field_ty.is_scalar() || field_ty.is_enum() {
                 return Err(FederationError::internal(
@@ -206,7 +206,7 @@ fn process_subselection(
     subgraph_schema: &ValidFederationSchema,
     builder: &mut impl IntraSourceQueryGraphBuilderApi,
     node_cache: &mut IndexMap<Name, NodeIndex<u32>>,
-    properties_path: Option<Vec<Property>>,
+    properties_path: Option<Vec<Key>>,
 ) -> Result<NodeIndex<u32>, FederationError> {
     // Get the type of the field
     let field_ty = field_output_type_pos.get(subgraph_schema.schema())?;
@@ -669,7 +669,7 @@ mod tests {
         use crate::source_aware::federated_query_graph::SelfConditionIndex;
         use crate::sources::connect::federated_query_graph::ConcreteFieldEdge;
         use crate::sources::connect::federated_query_graph::SourceEnteringEdge;
-        use crate::sources::connect::selection_parser::Property;
+        use crate::sources::connect::json_selection::Key;
         use crate::sources::connect::ConnectId;
         use crate::sources::source;
         use crate::sources::source::SourceId;
@@ -690,7 +690,7 @@ mod tests {
         /// A mock query edge
         struct MockEdge {
             field_name: Name,
-            path: Vec<Property>,
+            path: Vec<Key>,
         }
         impl Display for MockEdge {
             fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -702,13 +702,13 @@ mod tests {
                 }
 
                 // Helper for checking name equality of a property
-                fn is_name_eq(prop: &Property, other: &str) -> bool {
+                fn is_name_eq(prop: &Key, other: &str) -> bool {
                     match prop {
-                        Property::Field(f) => f == other,
-                        Property::Quoted(q) => q == other,
+                        Key::Field(f) => f == other,
+                        Key::Quoted(q) => q == other,
 
                         // No string name will be equal to a number
-                        Property::Index(_) => false,
+                        Key::Index(_) => false,
                     }
                 }
 

apollo-federation/src/sources/connect/federated_query_graph/mod.rs

@@ -6,10 +6,10 @@ use crate::schema::position::EnumTypeDefinitionPosition;
 use crate::schema::position::ObjectTypeDefinitionPosition;
 use crate::schema::position::ScalarTypeDefinitionPosition;
 use crate::schema::ObjectFieldDefinitionPosition;
-use crate::sources::connect::selection_parser::PathSelection;
-use crate::sources::connect::selection_parser::Property;
-use crate::sources::connect::Selection;
-use crate::sources::connect::SubSelection;
+use crate::sources::connect::json_selection::JSONSelection;
+use crate::sources::connect::json_selection::Key;
+use crate::sources::connect::json_selection::PathSelection;
+use crate::sources::connect::json_selection::SubSelection;
 use crate::sources::source;
 use crate::sources::source::federated_query_graph::FederatedQueryGraphApi;
 use crate::sources::source::SourceId;
@@ -42,7 +42,7 @@ pub(crate) enum ConcreteNode {
     },
     SelectionRoot {
         subgraph_type: ObjectTypeDefinitionPosition,
-        property_path: Vec<Property>,
+        property_path: Vec<Key>,
     },
     SelectionChild {
         subgraph_type: ObjectTypeDefinitionPosition,
@@ -53,7 +53,7 @@ pub(crate) enum ConcreteNode {
 pub(crate) enum EnumNode {
     SelectionRoot {
         subgraph_type: EnumTypeDefinitionPosition,
-        property_path: Vec<Property>,
+        property_path: Vec<Key>,
     },
     SelectionChild {
         subgraph_type: EnumTypeDefinitionPosition,
@@ -64,11 +64,11 @@ pub(crate) enum EnumNode {
 pub(crate) enum ScalarNode {
     SelectionRoot {
         subgraph_type: ScalarTypeDefinitionPosition,
-        property_path: Vec<Property>,
+        property_path: Vec<Key>,
     },
     CustomScalarSelectionRoot {
         subgraph_type: ScalarTypeDefinitionPosition,
-        selection: Selection,
+        selection: JSONSelection,
     },
     SelectionChild {
         subgraph_type: ScalarTypeDefinitionPosition,
@@ -86,7 +86,7 @@ pub(crate) enum ConcreteFieldEdge {
     },
     Selection {
         subgraph_field: ObjectFieldDefinitionPosition,
-        property_path: Vec<Property>,
+        property_path: Vec<Key>,
     },
     CustomScalarPathSelection {
         subgraph_field: ObjectFieldDefinitionPosition,
@@ -95,7 +95,7 @@ pub(crate) enum ConcreteFieldEdge {
     CustomScalarStarSelection {
         subgraph_field: ObjectFieldDefinitionPosition,
         star_subselection: Option<SubSelection>,
-        excluded_properties: IndexSet<Property>,
+        excluded_properties: IndexSet<Key>,
     },
 }
 

apollo-federation/src/sources/connect/fetch_dependency_graph/mod.rs

@@ -16,10 +16,10 @@ use crate::source_aware::federated_query_graph::FederatedQueryGraph;
 use crate::source_aware::federated_query_graph::SelfConditionIndex;
 use crate::source_aware::query_plan::FetchDataPathElement;
 use crate::source_aware::query_plan::QueryPlanCost;
-use crate::sources::connect::selection_parser::PathSelection;
-use crate::sources::connect::selection_parser::Property;
-use crate::sources::connect::Selection;
-use crate::sources::connect::SubSelection;
+use crate::sources::connect::json_selection::JSONSelection;
+use crate::sources::connect::json_selection::Key;
+use crate::sources::connect::json_selection::PathSelection;
+use crate::sources::connect::json_selection::SubSelection;
 use crate::sources::source;
 use crate::sources::source::fetch_dependency_graph::FetchDependencyGraphApi;
 use crate::sources::source::fetch_dependency_graph::PathApi;
@@ -124,7 +124,7 @@ pub(crate) struct Node {
     source_entering_edge: EdgeIndex,
     field_response_name: Name,
     field_arguments: IndexMap<Name, Value>,
-    selection: Selection,
+    selection: JSONSelection,
 }
 
 #[derive(Debug)]
@@ -145,26 +145,26 @@ pub(crate) struct PathField {
 #[derive(Debug)]
 pub(crate) enum PathSelections {
     Selections {
-        head_property_path: Vec<Property>,
-        named_selections: Vec<(Name, Vec<Property>)>,
+        head_property_path: Vec<Key>,
+        named_selections: Vec<(Name, Vec<Key>)>,
         tail_selection: Option<(Name, PathTailSelection)>,
     },
     CustomScalarRoot {
-        selection: Selection,
+        selection: JSONSelection,
     },
 }
 
 #[derive(Debug)]
 pub(crate) enum PathTailSelection {
     Selection {
-        property_path: Vec<Property>,
+        property_path: Vec<Key>,
     },
     CustomScalarPathSelection {
         path_selection: PathSelection,
     },
     CustomScalarStarSelection {
         star_subselection: Option<SubSelection>,
-        excluded_properties: IndexSet<Property>,
+        excluded_properties: IndexSet<Key>,
     },
 }
 
@@ -205,7 +205,7 @@ mod tests {
     use crate::sources::connect::federated_query_graph::ConcreteFieldEdge;
     use crate::sources::connect::federated_query_graph::ConcreteNode;
     use crate::sources::connect::federated_query_graph::SourceEnteringEdge;
-    use crate::sources::connect::selection_parser::Property;
+    use crate::sources::connect::json_selection::Key;
     use crate::sources::connect::ConnectId;
     use crate::sources::source::fetch_dependency_graph::FetchDependencyGraphApi;
     use crate::sources::source::SourceId;
@@ -272,7 +272,7 @@ mod tests {
                 source_id: source_id.clone(),
                 source_data: ConcreteNode::SelectionRoot {
                     subgraph_type: node_type.clone(),
-                    property_path: vec![Property::Field(type_name.to_lowercase().to_string())],
+                    property_path: vec![Key::Field(type_name.to_lowercase().to_string())],
                 }
                 .into(),
             });