feat: add environment variable to override version downloaded (#155)

* feat: add environment variable to override version downloaded

* Fixup test and remove logging

Author: John Kleinschmidt

README.md

@@ -87,6 +87,18 @@ const zipFilePath = await download('4.0.4', {
 // Will download from https://mirror.example.com/electron/version-4.0.4/electron-v4.0.4-linux-x64.zip
 ```
 
+#### Using environment variables for mirror options
+Mirror options can also be specified via the following environment variables:
+* `ELECTRON_CUSTOM_DIR` - Specifies the custom directory to download from.
+* `ELECTRON_CUSTOM_FILENAME` - Specifies the custom file name to download.
+* `ELECTRON_MIRROR` - Specifies the URL of the server to download from if the version is not a nightly version.
+* `ELECTRON_NIGHTLY_MIRROR` - Specifies the URL of the server to download from if the version is a nightly version.
+
+### Overriding the version downloaded
+
+The version downloaded can be overriden by setting the `ELECTRON_CUSTOM_VERSION` environment variable.
+Setting this environment variable will override the version passed in to `download` or `downloadArtifact`.
+
 ## How It Works
 
 This module downloads Electron to a known place on your system and caches it

src/index.ts

@@ -76,8 +76,10 @@ export async function downloadArtifact(
     }
   }
   ensureIsTruthyString(artifactDetails, 'version');
-  artifactDetails.version = normalizeVersion(artifactDetails.version);
 
+  artifactDetails.version = normalizeVersion(
+    process.env.ELECTRON_CUSTOM_VERSION || artifactDetails.version,
+  );
   const fileName = getArtifactFileName(artifactDetails);
   const url = getArtifactRemoteURL(artifactDetails);
   const cache = new Cache(artifactDetails.cacheRoot);
@@ -134,7 +136,6 @@ export async function downloadArtifact(
         downloader: artifactDetails.downloader,
         mirrorOptions: artifactDetails.mirrorOptions,
       });
-
       await sumchecker('sha256', shasumPath, path.dirname(tempDownloadPath), [
         path.basename(tempDownloadPath),
       ]);

test/index.spec.ts

@@ -112,6 +112,19 @@ describe('Public API', () => {
         downloadOptions: downloadOpts,
       });
     });
+
+    it('should download a custom version of a zip file', async () => {
+      process.env.ELECTRON_CUSTOM_VERSION = '2.0.10';
+      const zipPath = await download('2.0.3', {
+        cacheRoot,
+        downloader,
+      });
+      expect(typeof zipPath).toEqual('string');
+      expect(await fs.pathExists(zipPath)).toEqual(true);
+      expect(path.basename(zipPath)).toMatch(/v2.0.10/);
+      expect(path.extname(zipPath)).toEqual('.zip');
+      process.env.ELECTRON_CUSTOM_VERSION = '';
+    });
   });
 
   describe('downloadArtifact()', () => {
@@ -179,5 +192,22 @@ describe('Public API', () => {
       );
       expect(path.extname(driverPath)).toEqual('.zip');
     });
+
+    it('should download a custom version of a zip file', async () => {
+      process.env.ELECTRON_CUSTOM_VERSION = '2.0.10';
+      const zipPath = await downloadArtifact({
+        artifactName: 'electron',
+        cacheRoot,
+        downloader,
+        platform: 'darwin',
+        arch: 'x64',
+        version: '2.0.3',
+      });
+      expect(typeof zipPath).toEqual('string');
+      expect(await fs.pathExists(zipPath)).toEqual(true);
+      expect(path.basename(zipPath)).toMatchInlineSnapshot(`"electron-v2.0.10-darwin-x64.zip"`);
+      expect(path.extname(zipPath)).toEqual('.zip');
+      process.env.ELECTRON_CUSTOM_VERSION = '';
+    });
   });
 });