fix(migrate): preserve unmigrated Prettier projects

Author: fengmk2

docs/guide/migrate-rules.md

@@ -192,5 +192,6 @@ lint autofix preserves these imports.
 After updating the manifests and package-manager configuration, migration
 reinstalls dependencies once to refresh the lockfile. If installation fails,
 migration reports the error and exits with a nonzero status. After a successful
-migration, it runs `vp fmt`. A formatter failure is reported as a warning
-so the migration result and manual formatting command remain available.
+migration, it runs `vp fmt` unless the project still uses Prettier. A formatter
+failure is reported as a warning so the migration result and manual formatting
+command remain available.

packages/cli/snap-tests-global/migration-framework-shim-astro-vue/snap.txt

@@ -1,13 +1,17 @@
 > vp migrate --no-interactive --no-hooks # migration should add both Vue and Astro shims
+
+Formatting code...
+
+Code formatted
 ◇ Migrated . to Vite+
 • Node <semver>  pnpm <semver>
 ✓ Dependencies installed in <variable>ms
 • 1 config update applied
 • TypeScript shim added for framework component files
 
 > cat src/env.d.ts # check both shims were written
-declare module '*.vue' {
-  import type { DefineComponent } from 'vue';
+declare module "*.vue" {
+  import type { DefineComponent } from "vue";
   const component: DefineComponent<{}, {}, unknown>;
   export default component;
 }

packages/cli/snap-tests-global/migration-framework-shim-astro/snap.txt

@@ -1,4 +1,8 @@
 > vp migrate --no-interactive --no-hooks # migration should add Astro shim when astro dependency is detected
+
+Formatting code...
+
+Code formatted
 ◇ Migrated . to Vite+
 • Node <semver>  pnpm <semver>
 ✓ Dependencies installed in <variable>ms

packages/cli/snap-tests-global/migration-framework-shim-vue/snap.txt

@@ -1,13 +1,17 @@
 > vp migrate --no-interactive --no-hooks # migration should add Vue shim when vue dependency is detected
+
+Formatting code...
+
+Code formatted
 ◇ Migrated . to Vite+
 • Node <semver>  pnpm <semver>
 ✓ Dependencies installed in <variable>ms
 • 1 config update applied
 • TypeScript shim added for framework component files
 
 > cat src/env.d.ts # check Vue shim was written
-declare module '*.vue' {
-  import type { DefineComponent } from 'vue';
+declare module "*.vue" {
+  import type { DefineComponent } from "vue";
   const component: DefineComponent<{}, {}, unknown>;
   export default component;
 }

packages/cli/snap-tests-global/migration-standalone-npm/snap.txt

@@ -1,4 +1,8 @@
 > vp migrate --no-interactive --no-hooks # migration should work with npm, add overrides, and update lockfile
+
+Formatting code...
+
+Code formatted
 ◇ Migrated . to Vite+
 • Node <semver>  npm <semver>
 ✓ Dependencies installed in <variable>ms
@@ -11,10 +15,10 @@
     "vite": "npm:@voidzero-dev/vite-plus-core@<semver>",
     "vite-plus": "<semver>"
   },
-  "packageManager": "npm@<semver>",
   "overrides": {
     "vite": "npm:@voidzero-dev/vite-plus-core@<semver>"
-  }
+  },
+  "packageManager": "npm@<semver>"
 }
 
 > node -e "const lock = require('./package-lock.json'); const vite = lock.packages['node_modules/vite']; if (vite && (vite.name === '@voidzero-dev/vite-plus-core' || vite.resolved?.includes('/@voidzero-dev/vite-plus-core/'))) console.log('lockfile has vite override'); else { console.error('vite override not found in lockfile'); process.exit(1); }" # verify lockfile updated with override

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

@@ -1,4 +1,8 @@
 > vp migrate --no-interactive --no-hooks --package-manager pnpm # migration should work with pnpm, write overrides and peerDependencyRules to pnpm-workspace.yaml
+
+Formatting code...
+
+Code formatted
 ◇ Migrated . to Vite+
 • Node <semver>  pnpm <semver>
 ✓ Dependencies installed in <variable>ms
@@ -19,9 +23,9 @@ catalog:
   vite: npm:@voidzero-dev/vite-plus-core@<semver>
   vite-plus: <semver>
 overrides:
-  vite: 'catalog:'
+  vite: "catalog:"
 peerDependencyRules:
   allowAny:
     - vite
   allowedVersions:
-    vite: '*'
+    vite: "*"

packages/cli/src/migration/__tests__/format.spec.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it, vi } from 'vitest';
 
-import { formatMigratedProject } from '../format.ts';
+import { canFormatWithOxfmt, formatMigratedProject } from '../format.ts';
 import { createMigrationReport } from '../report.ts';
 
 describe('formatMigratedProject', () => {
@@ -45,3 +45,17 @@ describe('formatMigratedProject', () => {
     ]);
   });
 });
+
+describe('canFormatWithOxfmt', () => {
+  it('formats projects that do not use Prettier', () => {
+    expect(canFormatWithOxfmt(false, false)).toBe(true);
+  });
+
+  it('formats projects after Prettier was migrated', () => {
+    expect(canFormatWithOxfmt(true, true)).toBe(true);
+  });
+
+  it('does not reformat projects that still use Prettier', () => {
+    expect(canFormatWithOxfmt(true, false)).toBe(false);
+  });
+});

packages/cli/src/migration/bin.ts

@@ -46,7 +46,7 @@ import {
 import type { PackageDependencies } from '../utils/types.ts';
 import { detectWorkspace } from '../utils/workspace.ts';
 import { checkRolldownCompatibility } from './compat-runner.ts';
-import { formatMigratedProject } from './format.ts';
+import { canFormatWithOxfmt, formatMigratedProject } from './format.ts';
 import {
   addFrameworkShim,
   checkVitestVersion,
@@ -388,6 +388,7 @@ interface MigrationPlan extends MigrationSetupPlan {
   packageManager: PackageManager;
   yarnPnpConverted: boolean;
   migratePrettier: boolean;
+  hasPrettierDependency: boolean;
   prettierConfigFile?: string;
   fixBaseUrl: boolean;
   migrateNodeVersionFile: boolean;
@@ -724,6 +725,7 @@ async function collectMigrationPlan(
     yarnPnpConverted,
     ...setupPlan,
     migratePrettier,
+    hasPrettierDependency: prettierProject.hasDependency,
     prettierConfigFile: prettierProject.configFile,
     fixBaseUrl,
     migrateNodeVersionFile,
@@ -1159,7 +1161,10 @@ async function executeMigrationPlan(
     workspaceInfo.rootDir,
     report,
   );
-  if (finalInstallSummary.status === 'installed') {
+  if (
+    finalInstallSummary.status === 'installed' &&
+    canFormatWithOxfmt(plan.hasPrettierDependency, plan.migratePrettier)
+  ) {
     await formatMigratedProject(workspaceInfo.rootDir, interactive, report);
   }
   return {
@@ -1530,7 +1535,12 @@ async function main() {
       }
     }
 
-    if (didMigrate && finalInstallOk && canFormatMigratedProject) {
+    if (
+      didMigrate &&
+      finalInstallOk &&
+      canFormatMigratedProject &&
+      canFormatWithOxfmt(prettierProject.hasDependency, prettierMigrated)
+    ) {
       clearMigrationProgress();
       await formatMigratedProject(workspaceInfoOptional.rootDir, options.interactive, report);
     }

packages/cli/src/migration/format.ts

@@ -11,6 +11,17 @@ type FormatRunner = (
 const FORMAT_FAILURE_MESSAGE =
   'Automatic formatting failed. Run `vp fmt` manually after migration.';
 
+/**
+ * Do not apply Oxfmt to a project that still uses Prettier. Their formatting
+ * rules can conflict, especially when Prettier is enforced through ESLint.
+ */
+export function canFormatWithOxfmt(
+  hasPrettierDependency: boolean,
+  prettierMigrated: boolean,
+): boolean {
+  return !hasPrettierDependency || prettierMigrated;
+}
+
 /**
  * Format a successfully migrated project without turning a formatter problem
  * into an unhandled migration failure. The formatter already prints its