interface CustomRequestInit extends Omit { token?: string; body?: TBody; } export class FetchError extends Error { public status: number; public body?: string; constructor(response: Response, message?: string) { super(message || `HTTP error status: ${response.status}`); this.name = "FetchError"; this.status = response.status; // body만 저장 this.body = message; } } export async function fetcher( url: string, options: CustomRequestInit = {} ): Promise { const { token, body, ...fetchOptions } = options; const headers = new Headers(fetchOptions.headers); if (token) { headers.set("Authorization", `Bearer ${token}`); } // JSON 데이터인 경우 Content-Type 자동 설정 (FormData는 브라우저가 자동 설정) if ( body && typeof body === "object" && !(body instanceof FormData) && !(body instanceof File) && !(body instanceof Blob) && !headers.has("Content-Type") ) { headers.set("Content-Type", "application/json"); } try { const response = await fetch(url, { ...fetchOptions, headers, ...(body && { body: body instanceof FormData || body instanceof File || body instanceof Blob || typeof body === "string" ? body : typeof body === "object" ? JSON.stringify(body) : undefined, }), }); if (!response.ok) { const errorBody = await response.text().catch(() => "Unknown error"); const error = new FetchError(response, errorBody); throw new Error(error.message); } if (response.status === 204) { return {} as TResponse; } return response.json() as TResponse; } catch (error) { throw error; } } // 간단한 편의 메서드들 export const api = { get: (url: string, options?: Omit) => fetcher(url, { ...options, method: "GET" }), post: ( url: string, data?: TBody, options?: Omit, "method" | "body"> ) => fetcher(url, { ...options, method: "POST", body: data }), put: ( url: string, data?: TBody, options?: Omit, "method" | "body"> ) => fetcher(url, { ...options, method: "PUT", body: data }), delete: ( url: string, options?: Omit ) => fetcher(url, { ...options, method: "DELETE" }), };

Next.js 전용 Fetcher

Next.js용 Wrapper