写入文件名，但其文件大小为零字节

Question

我试图检查服务器上是否存在文件。如果没有，Node需要从指定的URL下载文件。以下是下载文件名，但文件大小为零（所以它没有正确下载）。我究竟做错了什么？

下载文件的代码位于catch块中。谢谢。

getApiDetails.then(
    apiData => {
        let imagesFolder = 'public/city_images/';
        // Only do the following if the city was found by the pixarbay api. If a city wasn't found, we assign it to default.jpg
        if (apiData.largeImageURL !== 'default.jpg') {

            const imageFileExtension = apiData.largeImageURL.substring(apiData.largeImageURL.lastIndexOf('.')+1);
            const imageFile = apiData.city+'.'+imageFileExtension;

            // Check whether file exists, if not, download it
            try {
                if(fs.statSync(__dirname+'/'+imagesFolder+imageFile).isFile()){
                    // Rename the path so it can be accessed like a local file and not always fetched from 3rd party api server (hotlinking is a no no)
                    apiData.largeImageURL = imagesFolder+imageFile;
                    resolve(apiData);
                }
            }
            catch(e) {
                // apiData.largeImageURL is an online jpeg file 
                let file = fs.createWriteStream(__dirname+'/'+imagesFolder+imageFile); // The path to the file the stream is writing to 
                https.get(apiData.largeImageURL, function(response) {
                    response.pipe(file);
                });
                // Rename the path so it can be accessed like a local file and not always fetched from 3rd party api server (hotlinking is a no no)
                apiData.largeImageURL = imagesFolder+imageFile;
                resolve(apiData);
            }

            ...