[backend] fix: 修复异常处理和类型转换问题

frontend/node_modules/get-stream/source/string.js

@@ -0,0 +1,36 @@
+import {getStreamContents} from './contents.js';
+import {identity, getContentsProp, throwObjectStream, getLengthProp} from './utils.js';
+
+export async function getStreamAsString(stream, options) {
+	return getStreamContents(stream, stringMethods, options);
+}
+
+const initString = () => ({contents: '', textDecoder: new TextDecoder()});
+
+const useTextDecoder = (chunk, {textDecoder}) => textDecoder.decode(chunk, {stream: true});
+
+const addStringChunk = (convertedChunk, {contents}) => contents + convertedChunk;
+
+const truncateStringChunk = (convertedChunk, chunkSize) => convertedChunk.slice(0, chunkSize);
+
+const getFinalStringChunk = ({textDecoder}) => {
+	const finalChunk = textDecoder.decode();
+	return finalChunk === '' ? undefined : finalChunk;
+};
+
+const stringMethods = {
+	init: initString,
+	convertChunk: {
+		string: identity,
+		buffer: useTextDecoder,
+		arrayBuffer: useTextDecoder,
+		dataView: useTextDecoder,
+		typedArray: useTextDecoder,
+		others: throwObjectStream,
+	},
+	getSize: getLengthProp,
+	truncateChunk: truncateStringChunk,
+	addChunk: addStringChunk,
+	getFinalChunk: getFinalStringChunk,
+	finalize: getContentsProp,
+};