fix(create): support system Yarn Classic template execution

Use the resolved Yarn version to select the existing npx fallback for Classic, which has no dlx command. Preserve Yarn 2+ template execution and cover runner selection, external scaffolding, and the built-in template version pin.

Author: SaKaNa-Y

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/snapshots.toml

@@ -40,3 +40,15 @@ name = "create_missing_system_pnpm"
 vp = "global"
 skip-platforms = ["windows"]
 steps = [["node", "verify.cjs", "pnpm", "missing"]]
+
+[[case]]
+name = "create_system_yarn_classic_external"
+vp = ["local", "global"]
+skip-platforms = ["windows"]
+steps = [{ argv = ["node", "verify.cjs", "yarn", "system", "external"], timeout = 180000 }]
+
+[[case]]
+name = "create_system_yarn_classic"
+vp = ["local", "global"]
+skip-platforms = ["windows"]
+steps = [["node", "verify.cjs", "yarn", "system", "classic"]]

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/snapshots/create_system_yarn_classic.global.md

@@ -0,0 +1,7 @@
+# create_system_yarn_classic
+
+## `node verify.cjs yarn system classic`
+
+```
+yarn: system version pinned
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/snapshots/create_system_yarn_classic.local.md

@@ -0,0 +1,7 @@
+# create_system_yarn_classic
+
+## `node verify.cjs yarn system classic`
+
+```
+yarn: system version pinned
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/snapshots/create_system_yarn_classic_external.global.md

@@ -0,0 +1,7 @@
+# create_system_yarn_classic_external
+
+## `node verify.cjs yarn system external`
+
+```
+yarn: external template generated with npx
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/snapshots/create_system_yarn_classic_external.local.md

@@ -0,0 +1,7 @@
+# create_system_yarn_classic_external
+
+## `node verify.cjs yarn system external`
+
+```
+yarn: external template generated with npx
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/create_system_package_manager/verify.cjs

@@ -3,8 +3,8 @@ const fs = require('node:fs');
 const path = require('node:path');
 const { spawnSync } = require('node:child_process');
 
-const [manager, mode] = process.argv.slice(2);
-const systemVersion = { npm: '10.9.3', pnpm: '10.18.0', yarn: '4.9.2', bun: '1.2.3' }[manager];
+const [manager, mode, template] = process.argv.slice(2);
+const systemVersion = manager === 'yarn' && (template === 'external' || template === 'classic') ? '1.22.22' : { npm: '10.9.3', pnpm: '10.18.0', yarn: '4.9.2', bun: '1.2.3' }[manager];
 const managedVersion = manager === 'npm' ? '11.6.0' : '10.18.0';
 const env = { ...process.env };
 const entryVp = env.PATH.split(path.delimiter).map(dir => path.join(dir, 'vp')).find(file => fs.existsSync(file));
@@ -35,8 +35,19 @@ run(['env', mode === 'managed' ? 'on' : 'off', manager]);
 const current = JSON.parse(run(['env', 'current', manager, '--json'])).package_manager;
 if (mode === 'system') assert.equal(current.source, 'system PATH');
 else assert.notEqual(current.source, 'system PATH');
-run(['create', 'vite:application', '--directory', 'app', '--package-manager', manager,
-  '--no-interactive', '--no-agent', '--no-editor', '--no-hooks', '--no-git']);
+const templateArgs = template === 'external' ? ['vite'] : ['vite:application', '--directory', 'app'];
+const output = run(['create', ...templateArgs, '--package-manager', manager,
+  '--no-interactive', '--no-agent', '--no-editor', '--no-hooks', '--no-git',
+  ...(template === 'external' ? ['--', 'app', '--template', 'vanilla'] : [])]);
+if (template === 'external') {
+  assert.match(output, /Running: npx --yes create-vite/);
+  const pkg = JSON.parse(fs.readFileSync('app/package.json', 'utf8'));
+  assert.equal(pkg.name, 'app');
+  assert.ok(fs.existsSync('app/index.html'));
+  assert.equal(current.version, systemVersion);
+  console.log(`${manager}: external template generated with npx`);
+  process.exit(0);
+}
 const pin = JSON.parse(fs.readFileSync('app/package.json', 'utf8')).devEngines.packageManager;
 assert.equal(pin.name, manager);
 assert.equal(pin.version, mode === 'system' ? systemVersion : managedVersion);

packages/cli/src/create/__tests__/command.spec.ts

@@ -4,6 +4,8 @@ import path from 'node:path';
 
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 
+import { PackageManager, type WorkspaceInfo } from '../../types/index.ts';
+
 const { mockRunCommand } = vi.hoisted(() => ({
   mockRunCommand: vi.fn(),
 }));
@@ -12,7 +14,7 @@ vi.mock('../../../binding/index.js', () => ({
   runCommand: mockRunCommand,
 }));
 
-const { runCommandAndDetectProjectDir } = await import('../command.js');
+const { formatDlxCommand, runCommandAndDetectProjectDir } = await import('../command.js');
 
 const tempDirs: string[] = [];
 
@@ -98,3 +100,30 @@ describe('runCommandAndDetectProjectDir', () => {
     });
   });
 });
+
+describe('formatDlxCommand', () => {
+  it.each([
+    ['1.22.22', 'npx', ['--yes']],
+    ['2.4.3', 'yarn', ['dlx']],
+    ['4.9.2', 'yarn', ['dlx']],
+  ])('runs templates with Yarn %s', (version, command, runnerArgs) => {
+    const workspace: WorkspaceInfo = {
+      rootDir: '/project',
+      isMonorepo: false,
+      monorepoScope: '',
+      workspacePatterns: [],
+      parentDirs: [],
+      packageManager: PackageManager.yarn,
+      // Ambient metadata can differ from the selected system version.
+      packageManagerVersion: '4.9.2',
+      downloadPackageManager: { name: 'yarn', version, binPrefix: '/system/bin' },
+      packages: [],
+    };
+    expect(
+      formatDlxCommand('@example/create-app@1.0.0', ['app', '--template', 'vanilla'], workspace),
+    ).toEqual({
+      command,
+      args: [...runnerArgs, '@example/create-app@1.0.0', 'app', '--template', 'vanilla'],
+    });
+  });
+});

packages/cli/src/create/command.ts

@@ -96,6 +96,10 @@ export function getPackageRunner(workspaceInfo: WorkspaceInfo) {
         args: ['dlx'],
       };
     case 'yarn':
+      // Match `vp dlx`: Yarn Classic has no dlx command.
+      if (workspaceInfo.downloadPackageManager.version.startsWith('1.')) {
+        return { command: 'npx', args: ['--yes'] };
+      }
       return {
         command: 'yarn',
         args: ['dlx'],