EPR data cannot be a Promise, only whole EPR

Author: mohawk2

src/execution/execute.js

@@ -116,7 +116,7 @@ export type ExecutionResult = {
  */
 export type ExecutionPartialResult<T> = MaybePromise<{
   errors?: $ReadOnlyArray<GraphQLError>,
-  data?: MaybePromise<T | null>,
+  data?: T | null,
 }>;
 
 export type ExecutionArgs = {|
@@ -265,20 +265,12 @@ function buildResponse(
   context: ExecutionContext,
   result: ExecutionPartialResult<mixed>,
 ) {
-  const resultpromise = getPromise(result);
-  if (resultpromise) {
-    return resultpromise.then(resolved =>
+  const promise = getPromise(result);
+  if (promise) {
+    return promise.then(resolved =>
       buildResponse(context, mergeErrors(context, resolved)),
     );
   }
-  if (result.data) {
-    const promise = getPromise(result.data);
-    if (promise) {
-      return promise.then(resolveddata =>
-        buildResponse(context, mergeErrors(context, { data: resolveddata })),
-      );
-    }
-  }
   if (result.data && (!result.errors || !result.errors.length)) {
     return { data: result.data };
   }
@@ -1110,7 +1102,7 @@ function completeListValue(
   });
 
   return containsPromise
-    ? { data: Promise.all(completedResults) }
+    ? Promise.all(completedResults).then(data => ({ data }))
     : { data: completedResults };
 }
 
@@ -1246,16 +1238,19 @@ function completeObjectValue(
         if (!isTypeOfResult) {
           throw invalidReturnTypeError(returnType, result, fieldNodes);
         }
-        return {
-          data: collectAndExecuteSubfields(
-            exeContext,
-            returnType,
-            fieldNodes,
-            info,
-            path,
-            result,
-          ),
-        };
+        const data = collectAndExecuteSubfields(
+          exeContext,
+          returnType,
+          fieldNodes,
+          info,
+          path,
+          result,
+        );
+        const subpromise = getPromise(data);
+        if (subpromise) {
+          return subpromise.then(d => ({ data: d }));
+        }
+        return { data };
       });
     }
 
@@ -1264,16 +1259,19 @@ function completeObjectValue(
     }
   }
 
-  return {
-    data: collectAndExecuteSubfields(
-      exeContext,
-      returnType,
-      fieldNodes,
-      info,
-      path,
-      result,
-    ),
-  };
+  const subfields = collectAndExecuteSubfields(
+    exeContext,
+    returnType,
+    fieldNodes,
+    info,
+    path,
+    result,
+  );
+  const subfpromise = getPromise(subfields);
+  if (subfpromise) {
+    return subfpromise.then(d => ({ data: d }));
+  }
+  return { data: subfields };
 }
 
 function invalidReturnTypeError(