vscode: replaced DownloadFileError with NestedError itself for simplicity

Author: Veetaha

editors/code/src/installation/download_file.ts

@@ -7,8 +7,6 @@ import { NestedError } from "ts-nested-error";
 
 const pipeline = util.promisify(stream.pipeline);
 
-class DownloadFileError extends NestedError {}
-
 /**
  * Downloads file from `url` and stores it at `destFilePath` with `destFilePermissions`.
  * `onProgress` callback is called on recieveing each chunk of bytes
@@ -21,13 +19,13 @@ export async function downloadFile(
     destFilePermissions: number,
     onProgress: (readBytes: number, totalBytes: number) => void
 ): Promise<void> {
-    const res = await fetch(url).catch(DownloadFileError.rethrow("Failed at initial fetch"));
+    const res = await fetch(url).catch(NestedError.rethrow("Failed at initial fetch"));
 
     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 DownloadFileError(`Got response ${res.status}`);
+        throw new NestedError(`Got response ${res.status}`);
     }
 
     const totalBytes = Number(res.headers.get('content-length'));
@@ -43,9 +41,12 @@ export async function downloadFile(
 
     const destFileStream = fs.createWriteStream(destFilePath, { mode: destFilePermissions });
 
-    await pipeline(res.body, destFileStream).catch(DownloadFileError.rethrow("Piping file error"));
+    await pipeline(res.body, destFileStream).catch(NestedError.rethrow("Piping file error"));
     return new Promise<void>(resolve => {
-        destFileStream.on("close", resolve); // details on workaround: https://github.com/rust-analyzer/rust-analyzer/pull/3092#discussion_r378191131
+        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
     });
 }