fix: keep prefetch results per argument set

src/Parameters/PrefetchDataParameter.php

@@ -53,11 +53,11 @@ public function resolve(object|null $source, array $args, mixed $context, Resolv
         // needed, GraphQL calls the callback of Deferred below. That's when we call the prefetch method,
         // already knowing all the requested fields (source-arguments combinations).
         return new Deferred(function () use ($source, $info, $context, $args, $prefetchBuffer) {
-            if (! $prefetchBuffer->hasResult($source)) {
+            if (! $prefetchBuffer->hasResult($source, $args, $info)) {
                 $this->processPrefetch($args, $context, $info, $prefetchBuffer);
             }
 
-            return $prefetchBuffer->getResult($source);
+            return $prefetchBuffer->getResult($source, $args, $info);
         });
     }
 
@@ -72,7 +72,7 @@ private function processPrefetch(array $args, mixed $context, ResolveInfo $info,
 
         foreach ($sources as $source) {
             // map results to each source to support old prefetch behavior
-            $prefetchBuffer->storeResult($source, $resolvedValues);
+            $prefetchBuffer->storeResult($source, $resolvedValues, $args, $info);
         }
     }
 

src/PrefetchBuffer.php

@@ -7,6 +7,7 @@
 use GraphQL\Type\Definition\ResolveInfo;
 use WeakMap;
 
+use function array_key_exists;
 use function md5;
 use function serialize;
 
@@ -18,7 +19,10 @@ class PrefetchBuffer
     /** @var array<string, array<int, object>> An array of buffered, indexed by hash of arguments. */
     private array $objects = [];
 
-    /** @var WeakMap A Storage of prefetch method results, holds source to resolved values. */
+    /**
+     * @var WeakMap<object, array<string, mixed>> Prefetch method results per source, indexed by hash of arguments, so
+     * aliases of one field with different arguments don't share a result.
+     */
     private WeakMap $results;
 
     public function __construct()
@@ -71,28 +75,49 @@ public function purge(
         unset($this->objects[$this->computeHash($arguments, $info)]);
     }
 
+    /** @param array<array-key, mixed> $arguments The input arguments passed from GraphQL to the field. */
     public function storeResult(
         object $source,
         mixed $result,
+        array $arguments = [],
+        ResolveInfo|null $info = null,
     ): void {
-        $this->results->offsetSet($source, $result);
+        $results = $this->results[$source] ?? [];
+        $results[$this->computeHash($arguments, $info)] = $result;
+        $this->results[$source] = $results;
     }
 
+    /** @param array<array-key, mixed> $arguments The input arguments passed from GraphQL to the field. */
     public function hasResult(
         object $source,
+        array $arguments = [],
+        ResolveInfo|null $info = null,
     ): bool {
-        return $this->results->offsetExists($source);
+        return array_key_exists($this->computeHash($arguments, $info), $this->results[$source] ?? []);
     }
 
+    /** @param array<array-key, mixed> $arguments The input arguments passed from GraphQL to the field. */
     public function getResult(
         object $source,
+        array $arguments = [],
+        ResolveInfo|null $info = null,
     ): mixed {
-        return $this->results->offsetGet($source);
+        return $this->results[$source][$this->computeHash($arguments, $info)];
     }
 
+    /** @param array<array-key, mixed> $arguments The input arguments passed from GraphQL to the field. */
     public function purgeResult(
         object $source,
+        array $arguments = [],
+        ResolveInfo|null $info = null,
     ): void {
-        $this->results->offsetUnset($source);
+        $results = $this->results[$source] ?? [];
+        unset($results[$this->computeHash($arguments, $info)]);
+
+        if ($results === []) {
+            unset($this->results[$source]);
+        } else {
+            $this->results[$source] = $results;
+        }
     }
 }

tests/Integration/EndToEndTest.php

@@ -194,6 +194,44 @@ public function testBatchPrefetching(): void
         );
     }
 
+    public function testPrefetchingSameFieldWithDifferentArguments(): void
+    {
+        $schema = $this->mainContainer->get(Schema::class);
+        assert($schema instanceof Schema);
+
+        $queryString = '
+        query {
+            contacts {
+                foo: repeatName(prefix:"foo", suffix:"")
+                bar: repeatName(prefix:"bar", suffix:"")
+                again: repeatName(prefix:"foo", suffix:"!")
+            }
+        }
+        ';
+
+        $result = GraphQL::executeQuery(
+            $schema,
+            $queryString,
+            null,
+            new Context(),
+        );
+
+        $this->assertSame([
+            'contacts' => [
+                [
+                    'foo' => 'fooJoe',
+                    'bar' => 'barJoe',
+                    'again' => 'fooJoe!',
+                ],
+                [
+                    'foo' => 'fooBill',
+                    'bar' => 'barBill',
+                    'again' => 'fooBill!',
+                ],
+            ],
+        ], $this->getSuccessResult($result));
+    }
+
     public function testDeprecatedField(): void
     {
         $schema = $this->mainContainer->get(Schema::class);

tests/Parameters/PrefetchDataParameterTest.php

@@ -29,7 +29,7 @@ public function testResolveWithExistingResult(): void
         ];
         $buffer = $context->getPrefetchBuffer($parameter);
 
-        $buffer->storeResult($source, $prefetchResult);
+        $buffer->storeResult($source, $prefetchResult, $args);
 
         $resolvedParameterPromise = $parameter->resolve($source, $args, $context, $this->createStub(ResolveInfo::class));
 

tests/PrefetchBufferTest.php

@@ -26,4 +26,28 @@ public function testRegister(): void
         $buffer->purge(['int'=>42]);
         $this->assertSame([], $buffer->getObjectsByArguments(['int'=>42]));
     }
+
+    public function testResultsPerArguments(): void
+    {
+        $buffer = new PrefetchBuffer();
+
+        $source = new stdClass();
+
+        $buffer->storeResult($source, 'foo', ['prefix' => 'foo']);
+        $buffer->storeResult($source, null, ['prefix' => 'bar']);
+
+        $this->assertTrue($buffer->hasResult($source, ['prefix' => 'foo']));
+        $this->assertTrue($buffer->hasResult($source, ['prefix' => 'bar']));
+        $this->assertFalse($buffer->hasResult($source, ['prefix' => 'baz']));
+        $this->assertFalse($buffer->hasResult($source));
+        $this->assertSame('foo', $buffer->getResult($source, ['prefix' => 'foo']));
+        $this->assertNull($buffer->getResult($source, ['prefix' => 'bar']));
+
+        $buffer->purgeResult($source, ['prefix' => 'foo']);
+        $this->assertFalse($buffer->hasResult($source, ['prefix' => 'foo']));
+        $this->assertTrue($buffer->hasResult($source, ['prefix' => 'bar']));
+
+        $buffer->purgeResult($source, ['prefix' => 'bar']);
+        $this->assertFalse($buffer->hasResult($source, ['prefix' => 'bar']));
+    }
 }

website/docs/CHANGELOG.md

@@ -72,6 +72,9 @@ sidebar_label: Changelog
   error without locations. GraphQLite now requires `webonyx/graphql-php` 15.38.3, whose `QueryComplexity` rule
   reports each invalid variable with its own located error.
   ([#839](https://github.com/thecodingmachine/graphqlite/pull/839)) @oojacoboo
+- A `#[Prefetch]` field selected twice on the same object with different arguments (two aliases) no longer
+  returns the first alias's prefetch result for both. `PrefetchBuffer` stores results per source and argument
+  set; its result methods take the arguments and `ResolveInfo` as optional trailing parameters. @oojacoboo
 
 ## >8.0.0