fix(cli): use runner configLoader to suppress Rolldown warnings in migration

Author: kazupon

packages/cli/snap-tests-global/migration-merge-vite-config-ts/package.json

@@ -17,6 +17,7 @@
   },
   "devDependencies": {
     "@vitejs/plugin-react": "^4.2.0",
+    "@vitest/browser-playwright": "^4.0.0",
     "oxfmt": "1",
     "oxlint": "1",
     "vite": "^7.0.0",

packages/cli/snap-tests-global/migration-monorepo-pnpm-overrides-dependency-selector/package.json

@@ -5,6 +5,7 @@
     "dev": "vite"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "vite": "catalog:"
   },
   "packageManager": "pnpm@10.20.0+sha512.cf9998222162dd85864d0a8102e7892e7ba4ceadebbf5a31f9c2fce48dfce317a9c53b9f6464d1ef9042cba2e02ae02a9f7c143a2b438cd93c91840f0192b9dd",

packages/cli/snap-tests-global/migration-monorepo-pnpm-overrides-dependency-selector/snap.txt

@@ -26,6 +26,7 @@ export default defineConfig({
     "prepare": "vp config"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "vite": "catalog:",
     "vite-plus": "catalog:"
   },

packages/cli/snap-tests-global/migration-monorepo-pnpm/package.json

@@ -16,6 +16,7 @@
     "testnpm2": "1.0.0"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "oxfmt": "catalog:",
     "oxlint": "catalog:",
     "vite": "catalog:",

packages/cli/snap-tests-global/migration-monorepo-pnpm/snap.txt

@@ -62,6 +62,7 @@ cat: .oxfmtrc.json: No such file or directory
     "testnpm2": "1.0.0"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "vite": "catalog:",
     "vitest": "catalog:",
     "vite-plus": "catalog:"

packages/cli/snap-tests-global/migration-monorepo-yarn4/package.json

@@ -19,6 +19,7 @@
     "testnpm2": "1.0.0"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "oxfmt": "catalog:",
     "oxlint": "catalog:",
     "vite": "catalog:",

packages/cli/snap-tests-global/migration-monorepo-yarn4/snap.txt

@@ -53,6 +53,7 @@ cat: .oxlintrc.json: No such file or directory
     "testnpm2": "1.0.0"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "catalog:",
     "vite": "catalog:",
     "vitest": "catalog:",
     "vite-plus": "catalog:"

packages/cli/src/migration/bin.ts

@@ -543,7 +543,12 @@ async function checkRolldownCompatibility(rootDir: string, report: MigrationRepo
   try {
     const { resolveConfig } = await import('../index.js');
     const { checkManualChunksCompat } = await import('./compat.js');
-    const config = await resolveConfig({ root: rootDir, logLevel: 'silent' }, 'build');
+    // Use 'runner' configLoader to avoid Rolldown bundling the config file,
+    // which prints UNRESOLVED_IMPORT warnings that cannot be suppressed via logLevel.
+    const config = await resolveConfig(
+      { root: rootDir, logLevel: 'silent', configLoader: 'runner' },
+      'build',
+    );
     checkManualChunksCompat(config.build?.rollupOptions?.output, report);
   } catch {
     // Config resolution may fail — skip compatibility check silently