[fusion] Fixed error caused by empty string arguments (#8618)

Author: michaelstaib

src/HotChocolate/Fusion-vnext/test/Fusion.AspNetCore.Tests/BookStoreTests.cs

@@ -540,6 +540,77 @@ public async Task Fetch_Books_With_Requirements_To_SourceSchema1_X_Times(int ite
         }
     }
 
+    [Fact]
+    public async Task Ensure_String_Literals_Can_Be_Empty()
+    {
+        // arrange
+        using var server1 = CreateSourceSchema(
+            "a",
+            b => b.AddQueryType<SourceSchema1.Query>());
+
+        using var server2 = CreateSourceSchema(
+            "b",
+            b => b.AddQueryType<SourceSchema2.Query>());
+
+        // act
+        using var gateway = await CreateCompositeSchemaAsync(
+        [
+            ("a", server1),
+            ("b", server2)
+        ]);
+
+        // assert
+        using var client = GraphQLHttpClient.Create(gateway.CreateClient());
+
+        using var result = await client.PostAsync(
+            """
+            {
+              formatTitle(title: "")
+            }
+            """,
+            new Uri("http://localhost:5000/graphql"));
+
+        // act
+        using var response = await result.ReadAsResultAsync();
+        response.MatchSnapshot();
+    }
+
+    [Fact]
+    public async Task Ensure_String_Variables_Can_Be_Empty()
+    {
+        // arrange
+        using var server1 = CreateSourceSchema(
+            "a",
+            b => b.AddQueryType<SourceSchema1.Query>());
+
+        using var server2 = CreateSourceSchema(
+            "b",
+            b => b.AddQueryType<SourceSchema2.Query>());
+
+        // act
+        using var gateway = await CreateCompositeSchemaAsync(
+        [
+            ("a", server1),
+            ("b", server2)
+        ]);
+
+        // assert
+        using var client = GraphQLHttpClient.Create(gateway.CreateClient());
+
+        using var result = await client.PostAsync(
+            """
+            query ($s: String!) {
+              formatTitle(title: $s)
+            }
+            """,
+            variables: new Dictionary<string, object?> { { "s", "" } },
+            new Uri("http://localhost:5000/graphql"));
+
+        // act
+        using var response = await result.ReadAsResultAsync();
+        response.MatchSnapshot();
+    }
+
     public static class SourceSchema1
     {
         public record Book(int Id, string Title, Author Author);
@@ -564,6 +635,9 @@ public Book GetBookById(int id)
             [UsePaging]
             public IEnumerable<Book> GetBooks()
                 => _books.Values;
+
+            public string FormatTitle(string title)
+                => title;
         }
     }
 

src/HotChocolate/Fusion-vnext/test/Fusion.AspNetCore.Tests/__snapshots__/BookStoreTests.Ensure_String_Literals_Can_Be_Empty.snap

@@ -0,0 +1,36 @@
+{
+  "data": {
+    "formatTitle": ""
+  },
+  "extensions": {
+    "fusion": {
+      "operationPlan": {
+        "id": "5f6d4777b547101a6afdcba10ab494bb886423fc03256b1499cc4d743d51d37e",
+        "operation": {
+          "kind": "Query",
+          "document": "{\n  formatTitle(title: \"\")\n}",
+          "id": "db37b9bf699a3623f803777a91ad4002",
+          "hash": "db37b9bf699a3623f803777a91ad4002",
+          "shortHash": "db37b9bf"
+        },
+        "nodes": [
+          {
+            "id": 1,
+            "type": "Operation",
+            "schema": "a",
+            "operation": {
+              "name": "Op_db37b9bf_1",
+              "type": "Query",
+              "document": "query Op_db37b9bf_1 {\n  formatTitle(title: \"\")\n}",
+              "hash": "f008a17a4990239900f3bc520624a85106689c0364d27a015aea3f7e2731b816",
+              "shortHash": "f008a17a"
+            },
+            "responseNames": [
+              "formatTitle"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}

src/HotChocolate/Fusion-vnext/test/Fusion.AspNetCore.Tests/__snapshots__/BookStoreTests.Ensure_String_Variables_Can_Be_Empty.snap

@@ -0,0 +1,36 @@
+{
+  "data": {
+    "formatTitle": ""
+  },
+  "extensions": {
+    "fusion": {
+      "operationPlan": {
+        "id": "d44a8ae58827d46da9c1a91590831908b04ec6c80f67e71ed0f4b0101cdd056d",
+        "operation": {
+          "kind": "Query",
+          "document": "query(\n  $s: String!\n) {\n  formatTitle(title: $s)\n}",
+          "id": "577373a9b2c16f480ac5c2645f109b7b",
+          "hash": "577373a9b2c16f480ac5c2645f109b7b",
+          "shortHash": "577373a9"
+        },
+        "nodes": [
+          {
+            "id": 1,
+            "type": "Operation",
+            "schema": "a",
+            "operation": {
+              "name": "Op_577373a9_1",
+              "type": "Query",
+              "document": "query Op_577373a9_1(\n  $s: String!\n) {\n  formatTitle(title: $s)\n}",
+              "hash": "9e1437a320d35e130c8630097be0d047b93df036081428b716822d6f0df8ae47",
+              "shortHash": "9e1437a3"
+            },
+            "responseNames": [
+              "formatTitle"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}

src/HotChocolate/Utilities/src/Utilities.Buffers/ArrayMemoryOwner.cs

@@ -32,7 +32,7 @@ public ArrayMemoryOwner(byte[] buffer, int start, int length)
 #if NET8_0_OR_GREATER
         ArgumentNullException.ThrowIfNull(buffer);
         ArgumentOutOfRangeException.ThrowIfLessThan(start, 0);
-        ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(length, 0);
+        ArgumentOutOfRangeException.ThrowIfLessThan(length, 0);
 #else
         if (buffer is null)
         {

src/HotChocolate/Utilities/src/Utilities.Buffers/ReadOnlyMemorySegment.cs

@@ -30,7 +30,7 @@ public ReadOnlyMemorySegment(IMemoryOwner<byte> owner, int start, int length)
 #if NET8_0_OR_GREATER
         ArgumentNullException.ThrowIfNull(owner);
         ArgumentOutOfRangeException.ThrowIfLessThan(start, 0);
-        ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(length, 0);
+        ArgumentOutOfRangeException.ThrowIfLessThan(length, 0);
 #else
         if (owner is null)
         {
@@ -81,7 +81,7 @@ public ReadOnlyMemorySegment(byte[] buffer, int start, int length)
 #if NET8_0_OR_GREATER
         ArgumentNullException.ThrowIfNull(buffer);
         ArgumentOutOfRangeException.ThrowIfLessThan(start, 0);
-        ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(length, 0);
+        ArgumentOutOfRangeException.ThrowIfLessThan(length, 0);
 #else
         if (buffer is null)
         {