Fixes for complex type merging (#1699)

= Fix cases where keys differ across subschemas = Fix multiple rounds of type merging Closes #1697. Thanks to @flux627 for reporting. Includes: * refactor tests * Shallow merge the field subschema map * Add required fields for keys * Add tests
ardatan · Jun 28, 2020 · b8815ad · b8815ad
1 parent 0f8be46
commit b8815ad
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diff --git a/packages/delegate/src/proxiedResult.ts b/packages/delegate/src/proxiedResult.ts
@@ -79,7 +79,7 @@ export function mergeProxiedResults(target: any, ...sources: Array<any>): any {
 
   const result = results.reduce(mergeDeep, target);
   result[FIELD_SUBSCHEMA_MAP_SYMBOL] = target[FIELD_SUBSCHEMA_MAP_SYMBOL]
-    ? mergeDeep(target[FIELD_SUBSCHEMA_MAP_SYMBOL], fieldSubschemaMap)
+    ? Object.assign({}, target[FIELD_SUBSCHEMA_MAP_SYMBOL], fieldSubschemaMap)
     : fieldSubschemaMap;
 
   const errors = sources.map((source: any) => (source instanceof Error ? source : source[ERROR_SYMBOL]));

diff --git a/packages/delegate/src/results/handleObject.ts b/packages/delegate/src/results/handleObject.ts
@@ -87,15 +87,28 @@ function collectSubFields(info: GraphQLResolveInfo, typeName: string): Record<st
     );
   });
 
-  const selectionSetsByField = (info.schema.extensions.stitchingInfo as StitchingInfo).selectionSetsByField;
+  const stitchingInfo = info.schema.extensions.stitchingInfo as StitchingInfo;
+  const selectionSetsByType = stitchingInfo.selectionSetsByType;
+  const selectionSetsByField = stitchingInfo.selectionSetsByField;
 
   Object.keys(subFieldNodes).forEach(responseName => {
     const fieldName = subFieldNodes[responseName][0].name.value;
-    if (selectionSetsByField[typeName] && selectionSetsByField[typeName][fieldName]) {
+    const typeSelectionSet = selectionSetsByType[typeName];
+    if (typeSelectionSet != null) {
       subFieldNodes = collectFields(
         partialExecutionContext,
         type,
-        selectionSetsByField[typeName][fieldName],
+        typeSelectionSet,
+        subFieldNodes,
+        visitedFragmentNames
+      );
+    }
+    const fieldSelectionSet = selectionSetsByField?.[typeName]?.[fieldName];
+    if (fieldSelectionSet != null) {
+      subFieldNodes = collectFields(
+        partialExecutionContext,
+        type,
+        fieldSelectionSet,
         subFieldNodes,
         visitedFragmentNames
       );