refactor: remove rootValue argument from executeOperation

`executeOperation` is never called with a `rootValue` different from `exeContext.rootValue` and `rootValue` is not utilized in the calling code except to pass its value to `executeOperation`. Rather than using an additional argument to `executeOperation`, the `rootValue`, the `rootValue` can be selected from the `exeContext` within `executeOperation`

Author: yaacovCR

src/execution/execute.ts

@@ -162,8 +162,6 @@ export interface ExecutionArgs {
  * a GraphQLError will be thrown immediately explaining the invalid input.
  */
 export function execute(args: ExecutionArgs): PromiseOrValue<ExecutionResult> {
-  const { rootValue } = args;
-
   // If a valid execution context cannot be created due to incorrect arguments,
   // a "Response" with only errors is returned.
   const exeContext = buildExecutionContext(args);
@@ -186,7 +184,7 @@ export function execute(args: ExecutionArgs): PromiseOrValue<ExecutionResult> {
   // in this case is the entire response.
   try {
     const { operation } = exeContext;
-    const result = executeOperation(exeContext, operation, rootValue);
+    const result = executeOperation(exeContext, operation);
     if (isPromise(result)) {
       return result.then(
         (data) => buildResponse(data, exeContext.errors),
@@ -349,7 +347,6 @@ export function buildExecutionContext(
 function executeOperation(
   exeContext: ExecutionContext,
   operation: OperationDefinitionNode,
-  rootValue: unknown,
 ): PromiseOrValue<ObjMap<unknown> | null> {
   const rootType = exeContext.schema.getRootType(operation.operation);
   if (rootType == null) {
@@ -368,6 +365,8 @@ function executeOperation(
   );
   const path = undefined;
 
+  const { rootValue } = exeContext;
+
   switch (operation.operation) {
     case OperationTypeNode.QUERY:
       return executeFields(exeContext, rootType, rootValue, path, rootFields);