removing some deduplication

leaf fields cannot be deterministically deduplicated because it is unclear which payload will complete first

Author: yaacovCR

src/execution/__tests__/defer-test.ts

@@ -591,7 +591,7 @@ describe('Execute: defer directive', () => {
     ]);
   });
 
-  it('Can deduplicate fields with deferred fragments at multiple levels', async () => {
+  it('Can deduplicate initial fields with deferred fragments at multiple levels', async () => {
     const document = parse(`
       query {
         hero {
@@ -642,13 +642,16 @@ describe('Execute: defer directive', () => {
         incremental: [
           {
             data: {
+              bar: 'bar',
+              baz: 'baz',
               bak: 'bak',
             },
             path: ['hero', 'nestedObject', 'deeperObject'],
           },
           {
             data: {
               deeperObject: {
+                bar: 'bar',
                 baz: 'baz',
               },
             },
@@ -729,7 +732,7 @@ describe('Execute: defer directive', () => {
     ]);
   });
 
-  it('can deduplicate fields with deferred fragments in different branches at multiple non-overlapping levels', async () => {
+  it('can deduplicate initial fields with deferred fragments in different branches at multiple non-overlapping levels', async () => {
     const document = parse(`
       query {
         a {
@@ -776,7 +779,9 @@ describe('Execute: defer directive', () => {
         incremental: [
           {
             data: {
-              e: {},
+              e: {
+                f: 'f',
+              },
             },
             path: ['a', 'b'],
           },

src/execution/execute.ts

@@ -669,25 +669,15 @@ function shouldExecuteFieldSet(
   fieldSet: ReadonlyArray<TaggedFieldNode>,
   deferDepth: number | undefined,
 ): boolean {
-  if (deferDepth === undefined) {
+  if (deferDepth === undefined || !isLeafType(getNamedType(returnType))) {
     return fieldSet.some(
-      ({ deferDepth: fieldDeferDepth }) => fieldDeferDepth === undefined,
+      ({ deferDepth: fieldDeferDepth }) => fieldDeferDepth === deferDepth,
     );
   }
 
-  if (!isLeafType(getNamedType(returnType))) {
-    let hasDepth = false;
-    for (const { deferDepth: fieldDeferDepth } of fieldSet) {
-      if (fieldDeferDepth === deferDepth) {
-        hasDepth = true;
-      }
-    }
-    return hasDepth;
-  }
-
   let hasDepth = false;
   for (const { deferDepth: fieldDeferDepth } of fieldSet) {
-    if (fieldDeferDepth === undefined || fieldDeferDepth < deferDepth) {
+    if (fieldDeferDepth === undefined) {
       return false;
     }
     if (fieldDeferDepth === deferDepth) {