feat: manually mirror opencoze's code from bytedance

Change-Id: I09a73aadda978ad9511264a756b2ce51f5761adf

frontend/packages/arch/fetch-stream/src/utils.ts

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2025 coze-dev Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+import {
+  type FetchSteamConfig,
+  FetchStreamErrorCode,
+  type FetchStreamErrorInfo,
+  type FetchStreamError,
+} from './type';
+
+export async function onStart(
+  response: Response,
+  inputOnStart: FetchSteamConfig<unknown, unknown>['onStart'],
+): Promise<void> {
+  await inputOnStart?.(response);
+
+  if (!(response.ok && response.body)) {
+    throw new Error(`Invalid Response, ResponseStatus: ${response.status}`);
+  }
+}
+
+export function validateChunk(decodedChunk: string): void {
+  let json: unknown;
+  try {
+    json = JSON.parse(decodedChunk);
+    // eslint-disable-next-line @coze-arch/no-empty-catch, @coze-arch/use-error-in-catch -- 设计如此
+  } catch {
+    /**
+     * 此处捕获 JSON.parse 错误不做任何处理
+     * 正常流式返回 json 解析失败才是正常的
+     */
+  }
+
+  if (
+    typeof json === 'object' &&
+    json !== null &&
+    'code' in json &&
+    json.code !== 0
+  ) {
+    throw json;
+  }
+}
+
+export function isFetchStreamErrorInfo(
+  error: unknown,
+): error is FetchStreamErrorInfo {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    'code' in error &&
+    'msg' in error
+  );
+}
+
+export function getStreamingErrorInfo(error: unknown): FetchStreamError {
+  let errorMsg =
+    'An exception occurred during the process of dealing with HTTP chunked streaming response.';
+  let errorCode = FetchStreamErrorCode.HttpChunkStreamingException;
+
+  if (error instanceof Error) {
+    errorMsg = error.message;
+  }
+
+  if (isFetchStreamErrorInfo(error)) {
+    errorMsg = error.msg;
+    errorCode = error.code;
+  }
+
+  return {
+    msg: errorMsg,
+    code: errorCode,
+    error,
+  };
+}
+
+export function getFetchErrorInfo(error: unknown): FetchStreamError {
+  const errorMsg = 'An exception occurred during the fetch';
+  const errorCode = FetchStreamErrorCode.FetchException;
+
+  return {
+    msg: error instanceof Error ? error.message : errorMsg,
+    code: errorCode,
+    error,
+  };
+}
+
+export function isAbortError(error: unknown): boolean {
+  return error instanceof DOMException && error.name === 'AbortError';
+}