Add optional array body Spector scenario

.chronus/changes/add-optional-array-body-spector-2026-6-2.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-specs"
+---
+
+Add Spector coverage for omitted optional array request bodies.

packages/http-specs/spec-summary.md

@@ -5431,6 +5431,13 @@ Expected Array input body:
 ["hello", null, "world"]
 ```
 
+### Type_Array_OptionalValue
+
+- Endpoint: `put /type/array/optional`
+
+Expected no request body.
+Expected Content-Type header: must NOT be present
+
 ### Type_Array_StringValue_get
 
 - Endpoint: `get /type/array/string`

packages/http-specs/specs/type/array/main.tsp

@@ -106,3 +106,15 @@ interface NullableModelValue
       NullableModel[],
       "[{'property': 'hello'}, null, {'property': 'world'}]"
     > {}
+
+@scenario
+@doc("Optional array value")
+@scenarioDoc("""
+  Expected no request body.
+  Expected Content-Type header: must NOT be present
+  """)
+@route("/optional")
+interface OptionalValue {
+  @put
+  omit(@body body?: string[]): void;
+}

packages/http-specs/specs/type/array/mockapi.ts

@@ -1,4 +1,10 @@
-import { json, passOnSuccess, ScenarioMockApi } from "@typespec/spec-api";
+import {
+  json,
+  MockRequest,
+  passOnSuccess,
+  ScenarioMockApi,
+  ValidationError,
+} from "@typespec/spec-api";
 
 export const Scenarios: Record<string, ScenarioMockApi> = {};
 
@@ -105,3 +111,25 @@ const Type_Array_Nullable_Model = createServerTests(`/type/array/nullable-model`
 ]);
 Scenarios.Type_Array_NullableModelValue_get = Type_Array_Nullable_Model.get;
 Scenarios.Type_Array_NullableModelValue_put = Type_Array_Nullable_Model.put;
+
+Scenarios.Type_Array_OptionalValue = passOnSuccess({
+  uri: "/type/array/optional/omit",
+  method: "put",
+  request: {},
+  response: {
+    status: 204,
+  },
+  handler: (req: MockRequest) => {
+    req.expect.rawBodyEquals(undefined);
+    const contentTypeHeader = req.headers["content-type"];
+    if (contentTypeHeader !== undefined) {
+      throw new ValidationError(
+        "Content-Type header must NOT be present when body is omitted",
+        undefined,
+        contentTypeHeader,
+      );
+    }
+    return { status: 204 };
+  },
+  kind: "MockApiDefinition",
+});