feat: allow notarization on macOS versions down to 10.15 (#201)

* notarytoolPath option

* Removed NotaryToolOptions interface

* Update README.md

Co-authored-by: Erick Zhao <[email protected]>

* Removed unnecessary typeof uses

---------

Co-authored-by: Erick Zhao <[email protected]>

README.md

@@ -40,10 +40,18 @@ For notarization, you need the following things:
 > If you are using Electron 11 or below, you must add the `com.apple.security.cs.allow-unsigned-executable-memory` entitlement too.
 > When using version 12+, this entitlement should not be applied as it increases your app's attack surface.
 
+### Notarization on older macOS versions
+
+Xcode 13 is available from macOS 11.3, but notarization can be performed on systems down to macOS 10.15
+(see [TN3147](https://developer.apple.com/documentation/technotes/tn3147-migrating-to-the-latest-notarization-tool#Enable-notarization-on-an-older-version-of-macOS) for more information).
+
+To achieve this, you can copy notarytool binary from a newer macOS version and provide its path as `notarytoolPath` option.
+
 ## API
 
 `@electron/notarize` exposes a single `notarize` function that accepts the following parameters:
 * `appPath` — the absolute path to your codesigned and packaged Electron application.
+* `notarytoolPath` - String (optional) - Path of the notarytool binary ([more details](#notarization-on-older-macos-versions)) 
 * additional options required for authenticating your Apple ID (see below)
 
 The method returns a void Promise once app notarization is complete. Please note that notarization may take

src/index.ts

@@ -45,7 +45,9 @@ async function notarize({ appPath, ...otherOptions }: NotarizeOptions) {
 
   d('notarizing using notarytool');
   if (!(await isNotaryToolAvailable())) {
-    throw new Error('notarytool is not available, you must be on at least Xcode 13');
+    throw new Error(
+      'notarytool is not available, you must be on at least Xcode 13 or provide notarytoolPath',
+    );
   }
 
   await notarizeAndWaitForNotaryTool({

src/notarytool.ts

@@ -12,6 +12,12 @@ import { NotaryToolCredentials, NotaryToolStartOptions } from './types';
 
 const d = debug('electron-notarize:notarytool');
 
+function runNotaryTool(args: string[], notarytoolPath?: string) {
+  const useXcrun = notarytoolPath === undefined;
+  const cmd = useXcrun ? 'xcrun' : notarytoolPath;
+  return spawn(cmd, useXcrun ? ['notarytool', ...args] : args);
+}
+
 function authorizationArgs(rawOpts: NotaryToolCredentials): string[] {
   const opts = validateNotaryToolAuthorizationArgs(rawOpts);
   if (isNotaryToolPasswordCredentials(opts)) {
@@ -43,17 +49,25 @@ function authorizationArgs(rawOpts: NotaryToolCredentials): string[] {
 
 async function getNotarizationLogs(opts: NotaryToolStartOptions, id: string) {
   try {
-    const logResult = await spawn('xcrun', ['notarytool', 'log', id, ...authorizationArgs(opts)]);
+    const logResult = await runNotaryTool(
+      ['log', id, ...authorizationArgs(opts)],
+      opts.notarytoolPath,
+    );
     d('notarization log', logResult.output);
     return logResult.output;
   } catch (e) {
     d('failed to pull notarization logs', e);
   }
 }
 
-export async function isNotaryToolAvailable() {
-  const result = await spawn('xcrun', ['--find', 'notarytool']);
-  return result.code === 0;
+export async function isNotaryToolAvailable(notarytoolPath?: string) {
+  if (notarytoolPath !== undefined) {
+    const result = await spawn(notarytoolPath, ['--version']);
+    return result.code === 0;
+  } else {
+    const result = await spawn('xcrun', ['--find', 'notarytool']);
+    return result.code === 0;
+  }
 }
 
 export async function notarizeAndWaitForNotaryTool(opts: NotaryToolStartOptions) {
@@ -83,7 +97,6 @@ export async function notarizeAndWaitForNotaryTool(opts: NotaryToolStartOptions)
     }
 
     const notarizeArgs = [
-      'notarytool',
       'submit',
       filePath,
       ...authorizationArgs(opts),
@@ -92,7 +105,7 @@ export async function notarizeAndWaitForNotaryTool(opts: NotaryToolStartOptions)
       'json',
     ];
 
-    const result = await spawn('xcrun', notarizeArgs);
+    const result = await runNotaryTool(notarizeArgs, opts.notarytoolPath);
     const rawOut = result.output.trim();
 
     let parsed: any;

src/types.ts

@@ -129,6 +129,7 @@ export interface NotaryToolNotarizeAppOptions {
    * Absolute path to your packaged and codesigned Electron application.
    */
   appPath: string;
+  notarytoolPath?: string;
 }
 
 /**