Generated endpoint headers are not passed to fetch

[clemeth]

What are the steps to reproduce this issue?

1. Set headers: true and client: "fetch" in orval.config.ts.
2. Run orval.
3. Call a generated function with endpoint headers.

What happens?

The headers are not passed to fetch.

This is an example of generated code:

export const getUser = async (
  headers: GetUserHeaders,
  options?: RequestInit
): Promise<User> => {
  const res = await fetch(getGetUserUrl(), {
    ...options,
    method: "GET",
  });
  const data = await res.json();

  return data as User;
};

What were you expecting to happen?

The headers should be passed to fetch:

export const getUser = async (
  headers: GetUserHeaders,
  options?: RequestInit
): Promise<User> => {
  const res = await fetch(getGetUserUrl(), {
    ...options,
+   headers: { ...headers, ...options?.headers },
    method: "GET",
  });
  const data = await res.json();

  return data as User;
};

With axios it works as expected:

export const getUser = <TData = AxiosResponse<User>>(
  headers: GetUserHeaders,
  options?: AxiosRequestConfig
): Promise<TData> => {
  return axios.get(`http://127.0.0.1:3999/user`, {
    ...options,
    headers: { ...headers, ...options?.headers },
  });
};

What versions are you using?

orval: 7.3.0
react: 19.0.0

[melloware]

PR is welcome!