Function downloadFile

src/utils/downloader.ts:69–140

(
    urlString: string,
    redirectCount = 0,
)

 * @returns a Buffer of the file contents.
 */
export async function downloadFile(
    urlString: string,
    redirectCount = 0,
): Promise<Buffer> {
    if (redirectCount >= MAX_REDIRECTS) {
        throw new Error(`Too many redirects (max ${MAX_REDIRECTS})`);
    }

    const buffers: Buffer[] = [];

    return new Promise<Buffer>((resolve, reject) => {
        const request = https.request(new URL(urlString), (response) => {
            if (
                (response.statusCode === 301 || response.statusCode === 302) &&
                response.headers.location
            ) {
                // Redirect - download from new location
                return resolve(
                    downloadFile(response.headers.location, redirectCount + 1),
                );
            } else if (response.statusCode !== 200) {
                // Download failed - print error message
                const errorMsg = `Download failed with response code: ${response.statusCode}`;
                outputChannel.appendLine(errorMsg);
                reject(new Error(errorMsg));
            }

            // Downloading - hook up events
            const contentLength = response.headers["content-length"]
                ? response.headers["content-length"]
                : "0";
            const packageSize = parseInt(contentLength, 10);
            let downloadedBytes = 0;
            let downloadPercentage = 0;

            outputChannel.appendLine(
                `Download size: ${(packageSize / 1024 / 1024).toFixed(2)} MB`,
            );

            response.on("data", (data) => {
                downloadedBytes += data.length;
                buffers.push(data);

                // Update status bar item with percentage
                const newPercentage = Math.ceil(
                    100 * (downloadedBytes / packageSize),
                );
                if (newPercentage !== downloadPercentage) {
                    downloadPercentage = newPercentage;
                    outputChannel.appendLine(
                        `Downloaded ${downloadPercentage}%`,
                    );
                }
            });

            response.on("end", () => {
                resolve(Buffer.concat(buffers));
            });