feat: add optional "tempDirectory" download request option (#127)

src/index.ts

@@ -11,7 +11,7 @@ import { Cache } from './Cache';
 import { getDownloaderForSystem } from './downloader-resolver';
 import { initializeProxy } from './proxy';
 import {
-  withTempDirectory,
+  withTempDirectoryIn,
   normalizeVersion,
   getHostArch,
   ensureIsTruthyString,
@@ -99,7 +99,7 @@ export async function downloadArtifact(
     console.warn('For more info: https://electronjs.org/blog/linux-32bit-support');
   }
 
-  return await withTempDirectory(async tempFolder => {
+  return await withTempDirectoryIn(artifactDetails.tempDirectory, async tempFolder => {
     const tempDownloadPath = path.resolve(tempFolder, getArtifactFileName(artifactDetails));
 
     const downloader = artifactDetails.downloader || (await getDownloaderForSystem());

src/types.ts

@@ -60,6 +60,11 @@ export interface ElectronDownloadRequestOptions {
    * built-in [[GotDownloader]].
    */
   downloader?: Downloader<any>;
+  /**
+   * A temporary directory for downloads.
+   * It is used before artifacts are put into cache.
+   */
+  tempDirectory?: string;
 }
 
 export type ElectronPlatformArtifactDetails = {

src/utils.ts

@@ -3,25 +3,32 @@ import * as fs from 'fs-extra';
 import * as os from 'os';
 import * as path from 'path';
 
-export async function withTempDirectory<T>(fn: (directory: string) => Promise<T>): Promise<T> {
-  const directory = await fs.mkdtemp(path.resolve(os.tmpdir(), 'electron-download-'));
-
+async function useAndRemoveDirectory<T>(
+  directory: string,
+  fn: (directory: string) => Promise<T>,
+): Promise<T> {
   let result: T;
   try {
     result = await fn(directory);
-  } catch (err) {
-    await fs.remove(directory);
-    throw err;
-  }
-
-  try {
+  } finally {
     await fs.remove(directory);
-  } catch {
-    // Ignore error, it's just a temp dir
   }
   return result;
 }
 
+export async function withTempDirectoryIn<T>(
+  parentDirectory: string = os.tmpdir(),
+  fn: (directory: string) => Promise<T>,
+): Promise<T> {
+  const tempDirectoryPrefix = 'electron-download-';
+  const tempDirectory = await fs.mkdtemp(path.resolve(parentDirectory, tempDirectoryPrefix));
+  return useAndRemoveDirectory(tempDirectory, fn);
+}
+
+export async function withTempDirectory<T>(fn: (directory: string) => Promise<T>): Promise<T> {
+  return withTempDirectoryIn(undefined, fn);
+}
+
 export function normalizeVersion(version: string) {
   if (!version.startsWith('v')) {
     return `v${version}`;