test(core-utils): add test coverage for spawnPackageManager (#3868)

Author: dsanders11

packages/utils/core-utils/spec/package-manager.spec.ts

@@ -1,8 +1,10 @@
+import { spawn } from '@malept/cross-spawn-promise';
 import findUp from 'find-up';
 import { beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
 
-import { resolvePackageManager } from '../src/package-manager';
+import { resolvePackageManager, spawnPackageManager } from '../src/package-manager';
 
+vi.mock('@malept/cross-spawn-promise');
 vi.mock('find-up', async (importOriginal) => {
   const mod = await importOriginal<object>();
   return {
@@ -83,6 +85,19 @@ describe('package-manager', () => {
     });
   });
 
+  describe('spawnPackageManager', () => {
+    it('should trim the output', async () => {
+      vi.mocked(spawn).mockResolvedValue(' foo \n');
+      const result = await spawnPackageManager({
+        executable: 'npm',
+        install: 'install',
+        dev: '--save-dev',
+        exact: '--save-exact',
+      });
+      expect(result).toBe('foo');
+    });
+  });
+
   it('should use the package manager for the nearest ancestor lockfile if detected', async () => {
     vi.mocked(findUp).mockResolvedValue('yarn.lock');
     await expect(resolvePackageManager()).resolves.toHaveProperty('executable', 'yarn');