fix bug for discovery

src/validation/__tests__/OverlappingFieldsCanBeMergedRule-test.ts

@@ -1163,4 +1163,46 @@ describe('Validate: Overlapping fields can be merged', () => {
 
     expectErrors(query).toDeepEqual([]);
   });
+
+  it('finds conflicts in nested fragments', () => {
+    const n = 10000;
+    const fragments = Array.from(Array(n).keys()).reduce(
+      (acc, next) =>
+        acc.concat(`\n
+        fragment X${next + 1} on Query {
+          ...X${next}
+        }
+      `),
+      '',
+    );
+
+    const query = `
+      query Test {
+        type: conflict
+        ...X${n}
+      }
+      ${fragments}
+      fragment X0 on Query {
+        type: conflict2
+        __typename
+      }
+    `;
+    expectErrors(query).toDeepEqual(
+            [
+        {
+          "locations": [
+            {
+              "column": 9,
+              "line": 3
+            },
+            {
+              "column": 9,
+              "line": 50008
+            }
+          ],
+          "message": "Fields \"type\" conflict because \"conflict\" and \"conflict2\" are different fields. Use different aliases on the fields to fetch both if this was intentional."
+        }
+      ]
+    );
+  });
 });

src/validation/rules/OverlappingFieldsCanBeMergedRule.ts

@@ -223,7 +223,7 @@ function findConflictsWithinSelectionSet(
           comparedFragmentPairs,
           false,
           fieldMap,
-          fragmentName,
+          referencedFragmentName,
           discoveredFragments,
         );
       }
@@ -439,26 +439,26 @@ function findConflictsBetweenSubSelectionSets(
     );
   }
 
-  // (E) Then collect any conflicts between the provided collection of fields
-  // and any fragment names found in the given fragment.
-  while (discoveredFragments.length !== 0) {
-    const item = discoveredFragments.pop();
-    if (!item || comparedFragmentPairs.has(item[1], item[0], areMutuallyExclusive)) {
-      continue;
+    // (E) Then collect any conflicts between the provided collection of fields
+    // and any fragment names found in the given fragment.
+    while (discoveredFragments.length !== 0) {
+      const item = discoveredFragments.pop();
+      if (!item || comparedFragmentPairs.has(item[1], item[0], areMutuallyExclusive)) {
+        continue;
+      }
+      const [fragmentName, referencedFragmentName] = item;
+      comparedFragmentPairs.add(referencedFragmentName, fragmentName, areMutuallyExclusive);
+      collectConflictsBetweenFieldsAndFragment(
+        context,
+        conflicts,
+        cachedFieldsAndFragmentNames,
+        comparedFragmentPairs,
+        areMutuallyExclusive,
+        fieldMap1,
+        referencedFragmentName,
+        discoveredFragments,
+      );
     }
-    const [fragmentName, referencedFragmentName] = item;
-    comparedFragmentPairs.add(referencedFragmentName, fragmentName, areMutuallyExclusive);
-    collectConflictsBetweenFieldsAndFragment(
-      context,
-      conflicts,
-      cachedFieldsAndFragmentNames,
-      comparedFragmentPairs,
-      areMutuallyExclusive,
-      fieldMap1,
-      fragmentName,
-      discoveredFragments,
-    );
-  }
 
   // (I) Then collect conflicts between the second collection of fields and
   // those referenced by each fragment name associated with the first.
@@ -475,26 +475,26 @@ function findConflictsBetweenSubSelectionSets(
     );
   }
 
-  // (E) Then collect any conflicts between the provided collection of fields
-  // and any fragment names found in the given fragment.
-  while (discoveredFragments.length !== 0) {
-    const item = discoveredFragments.pop();
-    if (!item || comparedFragmentPairs.has(item[1], item[0], areMutuallyExclusive)) {
-      continue;
+      // (E) Then collect any conflicts between the provided collection of fields
+    // and any fragment names found in the given fragment.
+    while (discoveredFragments.length !== 0) {
+      const item = discoveredFragments.pop();
+      if (!item || comparedFragmentPairs.has(item[1], item[0], areMutuallyExclusive)) {
+        continue;
+      }
+      const [fragmentName, referencedFragmentName] = item;
+      comparedFragmentPairs.add(referencedFragmentName, fragmentName, areMutuallyExclusive);
+      collectConflictsBetweenFieldsAndFragment(
+        context,
+        conflicts,
+        cachedFieldsAndFragmentNames,
+        comparedFragmentPairs,
+        areMutuallyExclusive,
+        fieldMap2,
+        referencedFragmentName,
+        discoveredFragments,
+      );
     }
-    const [fragmentName, referencedFragmentName] = item;
-    comparedFragmentPairs.add(referencedFragmentName, fragmentName, areMutuallyExclusive);
-    collectConflictsBetweenFieldsAndFragment(
-      context,
-      conflicts,
-      cachedFieldsAndFragmentNames,
-      comparedFragmentPairs,
-      areMutuallyExclusive,
-      fieldMap2,
-      fragmentName,
-      discoveredFragments,
-    );
-  }
 
   // (J) Also collect conflicts between any fragment names by the first and
   // fragment names by the second. This compares each item in the first set of