refactor(migration): simplify JSON config merging by using direct file content (#378)

Improves the Vite config migration process by directly using JSON/JSONC content in JavaScript context instead of parsing and converting it. Since JSON is valid JavaScript, this approach:

1. Preserves comments in JSONC files (both `//` and `/* */` style)
2. Maintains the original formatting and structure of config files
3. Removes ~130 lines of complex JSON-to-JS conversion code
4. Fixes the TODO for handling JSONC files in the migrator

The PR includes tests to verify that comments in JSONC files are properly preserved during migration.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fengmk2

crates/vite_migration/src/vite_config.rs

@@ -21,16 +21,16 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   fmt: {
-    printWidth: 100,
-    tabWidth: 2,
-    semi: true,
-    singleQuote: true,
-    trailingComma: 'es5',
+    "printWidth": 100,
+    "tabWidth": 2,
+    "semi": true,
+    "singleQuote": true,
+    "trailingComma": "es5"
   },
   lint: {
-    rules: {
-      'no-unused-vars': 'error',
-    },
+    "rules": {
+      "no-unused-vars": "error"
+    }
   },
 });
 

packages/global/snap-tests/migration-auto-create-vite-config/snap.txt

@@ -20,13 +20,13 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   lib: {
-    entry: 'src/index.ts',
-    outDir: 'dist',
-    format: ['esm', 'cjs'],
-    dts: true,
-    inputOptions: {
-      cwd: './src',
-    },
+    "entry": "src/index.ts",
+    "outDir": "dist",
+    "format": ["esm", "cjs"],
+    "dts": true,
+    "inputOptions": {
+      "cwd": "./src"
+    }
   },
   server: {
     port: 3000,
@@ -69,13 +69,13 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   lib: {
-    entry: 'src/index.ts',
-    outDir: 'dist',
-    format: ['esm', 'cjs'],
-    dts: true,
-    inputOptions: {
-      cwd: './src',
-    },
+    "entry": "src/index.ts",
+    "outDir": "dist",
+    "format": ["esm", "cjs"],
+    "dts": true,
+    "inputOptions": {
+      "cwd": "./src"
+    }
   },
   server: {
     port: 3000,

packages/global/snap-tests/migration-from-tsdown-json-config/snap.txt

@@ -17,9 +17,9 @@ import react from '@vitejs/plugin-react';
 
 export default {
   lint: {
-    rules: {
-      'no-unused-vars': 'error',
-    },
+    "rules": {
+      "no-unused-vars": "error"
+    }
   },
   plugins: [react()],
 }

packages/global/snap-tests/migration-merge-vite-config-js/snap.txt

@@ -27,16 +27,16 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   fmt: {
-    printWidth: 100,
-    tabWidth: 2,
-    semi: true,
-    singleQuote: true,
-    trailingComma: 'es5',
+    "printWidth": 100,
+    "tabWidth": 2,
+    "semi": true,
+    "singleQuote": true,
+    "trailingComma": "es5"
   },
   lint: {
-    rules: {
-      'no-unused-vars': 'error',
-    },
+    "rules": {
+      "no-unused-vars": "error"
+    }
   },
   plugins: [react()],
   test: {

packages/global/snap-tests/migration-merge-vite-config-ts/snap.txt

@@ -26,16 +26,16 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   fmt: {
-    printWidth: 100,
-    tabWidth: 2,
-    semi: true,
-    singleQuote: true,
-    trailingComma: 'es5',
+    "printWidth": 100,
+    "tabWidth": 2,
+    "semi": true,
+    "singleQuote": true,
+    "trailingComma": "es5"
   },
   lint: {
-    rules: {
-      'no-unused-vars': 'error',
-    },
+    "rules": {
+      "no-unused-vars": "error"
+    }
   },
   plugins: [react()],
 });
@@ -164,9 +164,9 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   lint: {
-    rules: {
-      'no-unused-vars': 'warn',
-    },
+    "rules": {
+      "no-unused-vars": "warn"
+    }
   },
 
 });

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

@@ -20,9 +20,9 @@ import { defineConfig } from '@voidzero-dev/vite-plus';
 
 export default defineConfig({
   lint: {
-    rules: {
-      'no-unused-vars': 'error',
-    },
+    "rules": {
+      "no-unused-vars": "error"
+    }
   },
   plugins: [react()],
 });

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

@@ -648,7 +648,6 @@ function mergeViteConfigFiles(projectPath: string): void {
     mergeAndRemoveJsonConfig(projectPath, viteConfig, configs.oxlintConfig, 'lint');
   }
   if (configs.oxfmtConfig) {
-    // TODO: handle jsonc file
     // merge oxfmt config into vite.config.ts
     mergeAndRemoveJsonConfig(projectPath, viteConfig, configs.oxfmtConfig, 'fmt');
   }