feat: allow custom URL resolution with resolveAssetURL

README.md

@@ -43,7 +43,7 @@ available:
   * `nightly_mirror` String (optional) - The Electron nightly-specific mirror URL.
   * `customDir` String (optional) - The name of the directory to download from, often scoped by version number.
   * `customFilename` String (optional) - The name of the asset to download.
-  * `baseOnly` Boolean (optional) - Whether to download from the base URL only.
+  * `resolveAssetURL` Function (optional) - A function allowing customization of the url used to download the asset.
 
 Anatomy of a download URL, in terms of `mirrorOptions`:
 

src/artifact-utils.ts

@@ -25,7 +25,7 @@ export function getArtifactFileName(details: ElectronArtifactDetails) {
 }
 
 function mirrorVar(
-  name: keyof Omit<MirrorOptions, 'baseOnly'>,
+  name: keyof Omit<MirrorOptions, 'resolveAssetURL'>,
   options: MirrorOptions,
   defaultValue: string,
 ) {
@@ -42,7 +42,7 @@ function mirrorVar(
   );
 }
 
-export function getArtifactRemoteURL(details: ElectronArtifactDetails): string {
+export async function getArtifactRemoteURL(details: ElectronArtifactDetails): Promise<string> {
   const opts: MirrorOptions = details.mirrorOptions || {};
   let base = mirrorVar('mirror', opts, BASE_URL);
   if (details.version.includes('nightly')) {
@@ -54,5 +54,11 @@ export function getArtifactRemoteURL(details: ElectronArtifactDetails): string {
   );
   const file = mirrorVar('customFilename', opts, getArtifactFileName(details));
 
-  return opts.baseOnly ? `${base}` : `${base}${path}/${file}`;
+  // Allow customized download URL resolution.
+  if (opts.resolveAssetURL) {
+    const url = await opts.resolveAssetURL(details);
+    return url;
+  }
+
+  return `${base}${path}/${file}`;
 }

src/index.ts

@@ -81,7 +81,7 @@ export async function downloadArtifact(
     process.env.ELECTRON_CUSTOM_VERSION || artifactDetails.version,
   );
   const fileName = getArtifactFileName(artifactDetails);
-  const url = getArtifactRemoteURL(artifactDetails);
+  const url = await getArtifactRemoteURL(artifactDetails);
   const cache = new Cache(artifactDetails.cacheRoot);
 
   // Do not check if the file exists in the cache when force === true

src/types.ts

@@ -21,10 +21,10 @@ export interface MirrorOptions {
    */
   customFilename?: string;
   /**
-   * Whether to download from the base URL only,
-   * ignoring customDir and customFilename
+   * A function allowing customization of the url returned
+   * from getArtifactRemoteURL().
    */
-  baseOnly?: boolean;
+  resolveAssetURL?: (opts: DownloadOptions) => Promise<string>;
 }
 
 export interface ElectronDownloadRequest {

test/artifact-utils.spec.ts

@@ -39,9 +39,9 @@ describe('artifact-utils', () => {
   });
 
   describe('getArtifactRemoteURL', () => {
-    it('should generate a default URL correctly', () => {
+    it('should generate a default URL correctly', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           platform: 'linux',
@@ -52,9 +52,9 @@ describe('artifact-utils', () => {
       );
     });
 
-    it('should replace the base URL when mirrorOptions.mirror is set', () => {
+    it('should replace the base URL when mirrorOptions.mirror is set', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {
@@ -66,26 +66,28 @@ describe('artifact-utils', () => {
       ).toMatchInlineSnapshot(`"https://mirror.example.com/v6.0.0/electron-v6.0.0-linux-x64.zip"`);
     });
 
-    it('should allow for setting only a base url when mirrorOptions.baseOnly is set', () => {
+    it('should allow for custom URL resolution with mirrorOptions.resolveAssetURL', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {
             mirror: 'https://mirror.example.com',
             customDir: 'v1.2.3',
             customFilename: 'custom-built-electron.zip',
-            baseOnly: true,
+            resolveAssetURL: opts => {
+              return opts.mirrorOptions.mirror || '';
+            },
           },
           platform: 'linux',
           version: 'v6.0.0',
         }),
       ).toMatchInlineSnapshot(`"https://mirror.example.com"`);
     });
 
-    it('should replace the nightly base URL when mirrorOptions.nightly_mirror is set', () => {
+    it('should replace the nightly base URL when mirrorOptions.nightly_mirror is set', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {
@@ -100,9 +102,9 @@ describe('artifact-utils', () => {
       );
     });
 
-    it('should replace the version dir when mirrorOptions.customDir is set', () => {
+    it('should replace the version dir when mirrorOptions.customDir is set', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {
@@ -116,9 +118,9 @@ describe('artifact-utils', () => {
       );
     });
 
-    it('should replace {{ version }} when mirrorOptions.customDir is set', () => {
+    it('should replace {{ version }} when mirrorOptions.customDir is set', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {
@@ -132,9 +134,9 @@ describe('artifact-utils', () => {
       );
     });
 
-    it('should replace the filename when mirrorOptions.customFilename is set', () => {
+    it('should replace the filename when mirrorOptions.customFilename is set', async () => {
       expect(
-        getArtifactRemoteURL({
+        await getArtifactRemoteURL({
           arch: 'x64',
           artifactName: 'electron',
           mirrorOptions: {