test: add unit tests for getOperationId (#6825)

Adds coverage for the previously untested getOperationId helper in
app/utils.ts (explicit operationId, method+path derivation, slash
replacement, and the allowed id pattern). Purely additive — no existing
files are changed.

Co-authored-by: ytj-zuel <15623621570>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Jeniter

test/get-operation-id.test.ts

@@ -0,0 +1,36 @@
+import { getOperationId } from "../app/utils";
+
+describe("getOperationId", () => {
+  test("prefers an explicit operationId when provided", () => {
+    expect(
+      getOperationId({
+        operationId: "listPets",
+        method: "get",
+        path: "/pets",
+      }),
+    ).toBe("listPets");
+  });
+
+  test("derives an id from method and path when operationId is missing", () => {
+    expect(
+      getOperationId({
+        method: "get",
+        path: "/pets/list",
+      }),
+    ).toBe("GET_pets_list");
+  });
+
+  test("uppercases the method and replaces every slash in the path", () => {
+    expect(
+      getOperationId({
+        method: "post",
+        path: "/v1/users/create",
+      }),
+    ).toBe("POST_v1_users_create");
+  });
+
+  test("produces an id matching the allowed pattern ^[a-zA-Z0-9_-]+$", () => {
+    const id = getOperationId({ method: "delete", path: "/a/b/c" });
+    expect(id).toMatch(/^[a-zA-Z0-9_-]+$/);
+  });
+});