import fetch from "node-fetch"; import * as fs from "fs"; import * as stream from "stream"; import * as util from "util"; import { strict as assert } from "assert"; const pipeline = util.promisify(stream.pipeline); /** * Downloads file from `url` and stores it at `destFilePath` with `destFilePermissions`. * `onProgress` callback is called on recieveing each chunk of bytes * to track the progress of downloading, it gets the already read and total * amount of bytes to read as its parameters. */ export async function downloadFile( url: string, destFilePath: fs.PathLike, destFilePermissions: number, onProgress: (readBytes: number, totalBytes: number) => void ): Promise { const res = await fetch(url); if (!res.ok) { console.log("Error", res.status, "while downloading file from", url); console.dir({ body: await res.text(), headers: res.headers }, { depth: 3 }); throw new Error(`Got response ${res.status} when trying to download a file.`); } const totalBytes = Number(res.headers.get('content-length')); assert(!Number.isNaN(totalBytes), "Sanity check of content-length protocol"); console.log("Downloading file of", totalBytes, "bytes size from", url, "to", destFilePath); let readBytes = 0; res.body.on("data", (chunk: Buffer) => { readBytes += chunk.length; onProgress(readBytes, totalBytes); }); const destFileStream = fs.createWriteStream(destFilePath, { mode: destFilePermissions }); await pipeline(res.body, destFileStream); return new Promise(resolve => { destFileStream.on("close", resolve); destFileStream.destroy(); // Details on workaround: https://github.com/rust-analyzer/rust-analyzer/pull/3092#discussion_r378191131 // Issue at nodejs repo: https://github.com/nodejs/node/issues/31776 }); }