feat: bump minimum node version to 16 and add tests (#86)

BREAKING CHANGE: Minimum node version is now 16

test/index.spec.ts

@@ -0,0 +1,40 @@
+import { spawn } from '@malept/cross-spawn-promise';
+import * as fs from 'fs-extra';
+import * as path from 'path';
+
+import { makeUniversalApp } from '../src/index';
+
+const appsPath = path.resolve(__dirname, 'fixtures', 'apps');
+
+async function ensureUniversal(app: string) {
+  const exe = path.resolve(app, 'Contents', 'MacOS', 'Electron');
+  const result = await spawn(exe);
+  expect(result).toContain('arm64');
+  const result2 = await spawn('arch', ['-x86_64', exe]);
+  expect(result2).toContain('x64');
+}
+
+describe('makeUniversalApp', () => {
+  it('should correctly merge two identical asars', async () => {
+    const out = path.resolve(appsPath, 'MergedAsar.app');
+    await makeUniversalApp({
+      x64AppPath: path.resolve(appsPath, 'X64Asar.app'),
+      arm64AppPath: path.resolve(appsPath, 'Asar.app'),
+      outAppPath: out,
+    });
+    await ensureUniversal(out);
+    // Only a single asar as they were identical
+    expect(
+      (await fs.readdir(path.resolve(out, 'Contents', 'Resources'))).filter((p) =>
+        p.endsWith('asar'),
+      ),
+    ).toEqual(['app.asar']);
+  }, 60000);
+
+  // TODO: Add tests for
+  // * different asar files
+  // * identical app dirs
+  // * different app dirs
+  // * different app dirs with different macho files
+  // * identical app dirs with universal macho files
+});