From 8b6887a09456d6db4edd08aec2923baca85e0aee Mon Sep 17 00:00:00 2001
From: Andrew Omondi <anomondi@microsoft.com>
Date: Mon, 6 May 2024 11:28:19 +0300
Subject: [PATCH 1/2] Fixes for multi dimensional arrays

---
 src/Kiota.Builder/KiotaBuilder.cs             |  3 +-
 .../Kiota.Builder.Tests/KiotaBuilderTests.cs  | 68 +++++++++++++++++++
 2 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/src/Kiota.Builder/KiotaBuilder.cs b/src/Kiota.Builder/KiotaBuilder.cs
index 5bcbcf7881..ef2920287b 100644
--- a/src/Kiota.Builder/KiotaBuilder.cs
+++ b/src/Kiota.Builder/KiotaBuilder.cs
@@ -1693,7 +1693,8 @@ private CodeTypeBase CreateModelDeclarations(OpenApiUrlTreeNode currentNode, Ope
             return CreateModelDeclarationAndType(currentNode, schema, operation, codeNamespace, suffix, response: responseValue, typeNameForInlineSchema: typeNameForInlineSchema, isRequestBody);
         }
 
-        if (schema.IsArray())
+        if (schema.IsArray() &&
+            !schema.Items.IsArray()) // Only handle collections of primitives and complex types. Otherwise, multi-dimensional arrays would be recursively unwrapped undesirably to lead to incorrect serialization types. 
         {
             // collections at root
             return CreateCollectionModelDeclaration(currentNode, schema, operation, codeNamespace, typeNameForInlineSchema, isRequestBody);
diff --git a/tests/Kiota.Builder.Tests/KiotaBuilderTests.cs b/tests/Kiota.Builder.Tests/KiotaBuilderTests.cs
index 66c5469c5a..82dabd2d6a 100644
--- a/tests/Kiota.Builder.Tests/KiotaBuilderTests.cs
+++ b/tests/Kiota.Builder.Tests/KiotaBuilderTests.cs
@@ -1273,6 +1273,74 @@ public void OData_doubles_as_any_of()
         Assert.Equal("double", progressProp.Type.Name);
     }
     [Fact]
+    public void MultiNestedArraysSupportedAsUntypedNodes()
+    {
+        var fooSchema = new OpenApiSchema
+        {
+            Type = "object",
+            Properties = new Dictionary<string, OpenApiSchema> {
+                {
+                    "sortBy", new OpenApiSchema {
+                        Type = "array",
+                        Items = new OpenApiSchema {
+                            Type = "array",
+                            Items = new OpenApiSchema {
+                                Type = "string"
+                            }
+                        }
+                    }
+                },
+            },
+            Reference = new OpenApiReference
+            {
+                Id = "#/components/schemas/bar.foo"
+            },
+            UnresolvedReference = false
+        };
+        var document = new OpenApiDocument
+        {
+            Paths = new OpenApiPaths
+            {
+                ["foos/{id}"] = new OpenApiPathItem
+                {
+                    Operations = {
+                        [OperationType.Get] = new OpenApiOperation
+                        {
+                            Responses = new OpenApiResponses {
+                                ["200"] = new OpenApiResponse
+                                {
+                                    Content = {
+                                        ["application/json"] = new OpenApiMediaType
+                                        {
+                                            Schema = fooSchema
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                },
+            },
+            Components = new OpenApiComponents
+            {
+                Schemas = new Dictionary<string, OpenApiSchema> {
+                    {
+                        "bar.foo", fooSchema
+                    }
+                }
+            }
+        };
+        var mockLogger = new CountLogger<KiotaBuilder>();
+        var builder = new KiotaBuilder(mockLogger, new GenerationConfiguration { ClientClassName = "Graph", ApiRootUrl = "https://localhost" }, _httpClient);
+        var node = builder.CreateUriSpace(document);
+        var codeModel = builder.CreateSourceModel(node);
+        var fooClass = codeModel.FindNamespaceByName("ApiSdk.models").FindChildByName<CodeClass>("foo");
+        Assert.NotNull(fooClass);
+        var sortByProp = fooClass.FindChildByName<CodeProperty>("sortBy", false);
+        Assert.NotNull(sortByProp);
+        Assert.Equal(KiotaBuilder.UntypedNodeName, sortByProp.Type.Name);// nested array property an UntypedNode
+    }
+    [Fact]
     public void Object_Arrays_are_supported()
     {
         var userSchema = new OpenApiSchema

From 4f0762ae83f797725cdc2135c3e1192453d38741 Mon Sep 17 00:00:00 2001
From: Andrew Omondi <anomondi@microsoft.com>
Date: Mon, 6 May 2024 12:21:48 +0300
Subject: [PATCH 2/2] Updates the changelog file

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d5b2b6b61..df485049c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Aligns naming of sliced OpenAPI description generated by `plugin add` should be named `<plugin-name>-openapi.json|yml`
 - Fixed RPC server to respect the `KIOTA_CONFIG_PREVIEW` flag.
+- Fixed handling of nested arrays to be handled as `UntypedNode` instances [#4549](https://github.com/microsoft/kiota/issues/4549)
 
 ## [1.14.0] - 2024-05-02