feat: make platform and arch optional in downloadArtifact (#109)

Fixes #107

Author: MarshallOfSound

src/index.ts

@@ -2,7 +2,11 @@ import debug from 'debug';
 import * as path from 'path';
 
 import { getArtifactFileName, getArtifactRemoteURL, FileNameUse } from './artifact-utils';
-import { ElectronArtifactDetails, ElectronDownloadRequestOptions } from './types';
+import {
+  ElectronArtifactDetails,
+  ElectronDownloadRequestOptions,
+  ElectronPlatformArtifactDetailsWithDefaults,
+} from './types';
 import { Cache } from './Cache';
 import { getDownloaderForSystem } from './downloader-resolver';
 import {
@@ -44,10 +48,18 @@ export function download(
  *
  * @param artifactDetails - The information required to download the artifact
  */
-export async function downloadArtifact(_artifactDetails: ElectronArtifactDetails): Promise<string> {
-  const artifactDetails: ElectronArtifactDetails = {
-    ..._artifactDetails,
-  };
+export async function downloadArtifact(
+  _artifactDetails: ElectronPlatformArtifactDetailsWithDefaults,
+): Promise<string> {
+  const artifactDetails: ElectronArtifactDetails = _artifactDetails.isGeneric
+    ? {
+        ..._artifactDetails,
+      }
+    : {
+        platform: process.platform,
+        arch: getHostArch(),
+        ..._artifactDetails,
+      };
   ensureIsTruthyString(artifactDetails, 'version');
   artifactDetails.version = normalizeVersion(artifactDetails.version);
 

src/types.ts

@@ -91,4 +91,13 @@ export type ElectronArtifactDetails =
   | ElectronPlatformArtifactDetails
   | ElectronGenericArtifactDetails;
 
+export type Omit<T, K> = Pick<T, Exclude<keyof T, K>>;
+
+export type ElectronPlatformArtifactDetailsWithDefaults =
+  | (Omit<ElectronPlatformArtifactDetails, 'platform' | 'arch'> & {
+      platform?: string;
+      arch?: string;
+    })
+  | ElectronGenericArtifactDetails;
+
 export type DownloadOptions = any;

test/index.spec.ts

@@ -120,6 +120,13 @@ describe('Public API', () => {
       expect(await fs.readFile(dtsPath, 'utf8')).toContain('declare namespace Electron');
     });
 
+    it('should work default platform/arch', async () => {
+      await downloadArtifact({
+        version: '2.0.3',
+        artifactName: 'electron',
+      });
+    });
+
     it('should work for chromedriver', async () => {
       const driverPath = await downloadArtifact({
         cacheRoot,