如何在打字稿中返回数组的承诺

Question

我试图以承诺的形式返回一个数组。我首先解压缩了一个文件，然后使用 csv-parse 解析了该文件。我将所有返回的对象保存在一个数组中，然后返回这个数组

我试图在没有保证转换器没有抱怨的情况下返回。但我想扩展它

/**
 * Wraps writeFile in a promise.
 * @param content The Base64 content of the file to read.
 * @returns A buffer containing the contents of the file.
 */
protected writeFileAsync(path: string, content: Buffer): Promise<IProblem[]> {
    new Promise<Buffer>((resolve, reject) => {
        fs.writeFile(path, content,  "base64", (err) => {
            if (err) {
                reject(err);
            }

            resolve(content);
        });
    })
    .then(result => {
        fs.readFile(result, (err, data) => {
            if (err) {
                Log.error("Error while reading the zip file");
                this.listOfProblems = [];
                return this.listOfProblems;
            }
            let zip: JSZip = new JSZip();
            zip.loadAsync(data)
            .then(contents => {
                Object.keys(contents.files).forEach(filename => {
                    zip.file(filename).async('nodebuffer')
                    .then(content => {
                        let parser: csvParse.Parser = csvParse((data, err) => {
                            if (err) {
                                Log.error("Error while reading the zip file");
                                this.listOfProblems = [];
                                return this.listOfProblems;
                            }
                            let problem: IProblem;

                        }) as csvParse.Parser;
                        fs.createReadStream(content).pipe(parser);
                    })
                })
            })
        })
    })
    .catch(() => {
        Log.error("Error while reading the zip file");
        this.listOfProblems = [];
        return this.listOfProblems;
    });
    return this.listOfProblems;
}

最后一行显示错误

Answer 1

你必须返回你的承诺，而不是列表。

return new Promise<Buffer>((resolve, reject) => {