fix: update test operation generator to find any operation in the ser…

…vice closure

When using operations nested under resources, the current search will raise "NoSuchElementException".
This fixes the search to include all operations within the service closure

aws/sdk-codegen/src/main/kotlin/software/amazon/smithy/rustsdk/endpoints/OperationInputTestGenerator.kt

@@ -5,6 +5,7 @@
 
 package software.amazon.smithy.rustsdk.endpoints
 
+import software.amazon.smithy.model.knowledge.TopDownIndex
 import software.amazon.smithy.model.node.Node
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ShapeId
@@ -222,4 +223,7 @@ class OperationInputTestGenerator(_ctx: ClientCodegenContext, private val test:
 }
 
 fun ClientCodegenContext.operationId(testOperationInput: EndpointTestOperationInput): ShapeId =
-    this.serviceShape.allOperations.first { it.name == testOperationInput.operationName }
+    TopDownIndex.of(this.model)
+        .getContainedOperations(this.serviceShape)
+        .map { it.toShapeId() }
+        .first { it.name == testOperationInput.operationName }

aws/sdk-codegen/src/test/kotlin/software/amazon/smithy/rustsdk/OperationInputTestGeneratorTests.kt

@@ -55,6 +55,50 @@ class OperationInputTestGeneratorTests {
         assertEquals("operations#Ping", operationId.toString())
     }
 
+    @Test
+    fun `finds operation shape by name from nested operations`() {
+        val prefix = "\$version: \"2\""
+        val operationModel =
+            """
+            $prefix
+            namespace operations.bells
+
+            resource Bell {
+                operations: [Ding]
+            }
+
+            operation Ding {}
+            """.trimIndent()
+        val serviceModel =
+            """
+            $prefix
+            namespace service
+
+            use operations.bells#Bell
+
+            service MyService {
+                resources: [Bell]
+            }
+            """.trimIndent()
+
+        val model =
+            Model.assembler()
+                .discoverModels()
+                .addUnparsedModel("operation.smithy", operationModel)
+                .addUnparsedModel("main.smithy", serviceModel)
+                .assemble()
+                .unwrap()
+
+        val context = testClientCodegenContext(model)
+        val testOperationInput =
+            EndpointTestOperationInput.builder()
+                .operationName("Ding")
+                .build()
+
+        val operationId = context.operationId(testOperationInput)
+        assertEquals("operations.bells#Ding", operationId.toString())
+    }
+
     @Test
     fun `fails for operation name not found`() {
         val model =