[1/x] Refactor root field builder for deferred fragments

Tests/ApolloCodegenInternalTestHelpers/IR+Mocking.swift

@@ -96,7 +96,7 @@ extension IR.Operation {
   public static func mock(
     definition: CompilationResult.OperationDefinition? = nil,
     referencedFragments: OrderedSet<IR.NamedFragment> = [],
-    hasDeferredFragments: Bool = false
+    containsDeferredFragment: Bool = false
   ) -> IR.Operation {
     let definition = definition ?? .mock()
     return IR.Operation.init(
@@ -116,7 +116,7 @@ extension IR.Operation {
           ])
       ),
       referencedFragments: referencedFragments,
-      hasDeferredFragments: hasDeferredFragments
+      containsDeferredFragment: containsDeferredFragment
     )
   }
 

Tests/ApolloCodegenInternalTestHelpers/MockIRSubscripts.swift

@@ -46,9 +46,25 @@ extension ScopeConditionalSubscriptAccessing {
     return self[scope]
   }
 
+  public subscript(
+    as typeCase: String? = nil,
+    deferred deferCondition: CompilationResult.DeferCondition? = nil
+  ) -> IR.SelectionSet? {
+    guard let scope = self.scopeCondition(
+      type: typeCase,
+      conditions: nil,
+      deferCondition: deferCondition
+    ) else {
+      return nil
+    }
+
+    return self[scope]
+  }
+
   private func scopeCondition(
     type typeCase: String?,
-    conditions conditionsResult: IR.InclusionConditions.Result?
+    conditions conditionsResult: IR.InclusionConditions.Result?,
+    deferCondition: CompilationResult.DeferCondition? = nil
   ) -> IR.ScopeCondition? {
     let type: GraphQLCompositeType?
     if let typeCase = typeCase {
@@ -70,7 +86,7 @@ extension ScopeConditionalSubscriptAccessing {
       conditions = nil
     }
 
-    return IR.ScopeCondition(type: type, conditions: conditions)
+    return IR.ScopeCondition(type: type, conditions: conditions, deferCondition: deferCondition)
   }
 
 }
@@ -145,6 +161,18 @@ extension IR.SelectionSet: ScopeConditionalSubscriptAccessing {
   public subscript(fragment fragment: String) -> IR.NamedFragmentSpread? {
     selections[fragment: fragment]
   }
+
+  public subscript(
+    deferredAs label: String,
+    withVariable variable: String? = nil
+  ) -> IR.SelectionSet? {
+    let scope = ScopeCondition(
+      type: self.parentType,
+      conditions: self.inclusionConditions,
+      deferCondition: CompilationResult.DeferCondition(label: label, variable: variable)
+    )
+    return selections[scope]
+  }
 }
 
 extension IR.SelectionSet.Selections: ScopeConditionalSubscriptAccessing {