Add endpoint rules and endpoint test to kitchensink model

Author: Madrigal

codegen/kitchensink-test-codegen/model/main.smithy

@@ -4,6 +4,78 @@ namespace aws.kitchensinktest
 @aws.api#service(sdkId: "awsJson1 kitchen sink")
 @aws.protocols#awsJson1_0
 @aws.auth#sigv4(name: "awsjson1kitchensink")
+@smithy.rules#endpointRuleSet({
+    version: "1.0",
+    parameters: {
+        Region: {
+            type: "string",
+            builtIn: "AWS::Region",
+            required: true,
+            documentation: "The AWS region"
+        },
+        Id: {
+            type: "string",
+            documentation: "The item id"
+        }
+    },
+    rules: [
+        {
+            type: "endpoint",
+            documentation: "id-specific endpoint",
+            conditions: [
+                { fn: "isSet", argv: [{ ref: "Id" }] }
+            ],
+            endpoint: {
+                url: "https://{Id}.example.{Region}.amazonaws.com"
+            }
+        },
+        {
+            type: "endpoint",
+            documentation: "Default regional endpoint",
+            conditions: [],
+            endpoint: {
+                url: "https://example.{Region}.amazonaws.com"
+            }
+        }
+    ]
+})
+@smithy.rules#endpointTests({
+    version: "1.0",
+    testCases: [
+        {
+            documentation: "id-specific endpoint",
+            params: {
+                Region: "us-east-1",
+                Id: "some-id"
+            },
+            operationInputs: [{
+                operationName: "GetItem",
+                "builtInParams": {
+                    "AWS::Region": "us-east-1"
+                }
+                operationParams: {
+                    id: "some-id",
+                }
+            }],
+            expect: {
+                endpoint: {
+                    url: "https://some-id.example.us-east-1.amazonaws.com"
+                }
+            }
+        },
+        {
+            documentation: "Default endpoint when id is not set",
+            params: {
+                Region: "us-west-2"
+            },
+            expect: {
+                endpoint: {
+                    url: "https://example.us-west-2.amazonaws.com"
+                }
+            }
+        }
+    ]
+})
 service AwsJson1KitchenSink {
     version: "2025-03-01",
     operations: [GetItem],
@@ -17,6 +89,8 @@ operation GetItem {
 
 structure GetItemInput {
     item: Item,
+    @smithy.rules#contextParam(name: "Id")
+    id: String,
 }
 
 structure GetItemOutput {}