fix(migrate): safely merge duplicate imports

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_duplicate_imports/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "migration-duplicate-imports",
+  "private": true,
+  "type": "module",
+  "devDependencies": {
+    "vite": "npm:@voidzero-dev/vite-plus-core@1.5.0",
+    "vite-plus": "1.5.0"
+  },
+  "packageManager": "pnpm@10.18.0"
+}

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

@@ -0,0 +1,17 @@
+[[case]]
+name = "migration_duplicate_imports"
+vp = "global"
+steps = [
+  ["vp", "migrate", "--no-interactive", "--no-hooks"],
+  { argv = ["vpt", "print-file", "vite.config.ts"], comment = "Merge the rewritten type import into the existing value import (issue #3430)." },
+]
+
+[[case]]
+name = "migration_duplicate_imports_preserve_code"
+vp = "global"
+steps = [
+  { argv = ["vpt", "replace-file-content", "vite.config.ts", "import { defineConfig }", "const keep = 'keep';\nimport './setup';\nimport { defineConfig }"], snapshot = false },
+  { argv = ["vpt", "write-file", "setup.ts", "export {};\n"], snapshot = false },
+  ["vp", "migrate", "--no-interactive", "--no-hooks"],
+  { argv = ["vpt", "print-file", "vite.config.ts"], comment = "Keep statements and side-effect imports between matching imports." },
+]

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_duplicate_imports/snapshots/migration_duplicate_imports.md

@@ -0,0 +1,29 @@
+# migration_duplicate_imports
+
+## `vp migrate --no-interactive --no-hooks`
+
+```
+VITE+ - The Unified Toolchain for the Web
+
+◇ Updated . to Vite+ <version>
+• Node <version>  pnpm <version>
+• Dependencies:
+    vite-plus  1.5.0 → <version>
+    vite             → <version>
+• 1 file had imports rewritten
+• Package manager settings configured
+```
+
+## `vpt print-file vite.config.ts`
+
+Merge the rewritten type import into the existing value import (issue #3430).
+
+```
+import { defineConfig, type Plugin } from 'vite-plus';
+
+const noop = (): Plugin => ({ name: 'noop' });
+
+export default defineConfig({
+  plugins: [noop()],
+});
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_duplicate_imports/snapshots/migration_duplicate_imports_preserve_code.md

@@ -0,0 +1,41 @@
+# migration_duplicate_imports_preserve_code
+
+## `vpt replace-file-content vite.config.ts 'import { defineConfig }' 'const keep = '\''keep'\'';
+import '\''./setup'\'';
+import { defineConfig }'`
+
+
+## `vpt write-file setup.ts 'export {};
+'`
+
+
+## `vp migrate --no-interactive --no-hooks`
+
+```
+VITE+ - The Unified Toolchain for the Web
+
+◇ Updated . to Vite+ <version>
+• Node <version>  pnpm <version>
+• Dependencies:
+    vite-plus  1.5.0 → <version>
+    vite             → <version>
+• 1 file had imports rewritten
+• Package manager settings configured
+```
+
+## `vpt print-file vite.config.ts`
+
+Keep statements and side-effect imports between matching imports.
+
+```
+import type { Plugin } from 'vite-plus';
+const keep = 'keep';
+import './setup';
+import { defineConfig } from 'vite-plus';
+
+const noop = (): Plugin => ({ name: 'noop' });
+
+export default defineConfig({
+  plugins: [noop()],
+});
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_duplicate_imports/vite.config.ts

@@ -0,0 +1,8 @@
+import type { Plugin } from 'vite';
+import { defineConfig } from 'vite-plus';
+
+const noop = (): Plugin => ({ name: 'noop' });
+
+export default defineConfig({
+  plugins: [noop()],
+});

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_merge_vite_config_ts/snapshots/migration_merge_wrapped_callback.md

@@ -25,7 +25,7 @@ VITE+ - The Unified Toolchain for the Web
   - Vitest v5: 1 review item
 
 vite.config.ts
-  9:29 REVIEW [dynamic-config] Review this dynamic config; explicit v4 compatibility settings need manual insertion.
+  7:29 REVIEW [dynamic-config] Review this dynamic config; explicit v4 compatibility settings need manual insertion.
     Docs: https://viteplus.dev/guide/vitest-v5#resolve-migration-findings
 ```
 
@@ -36,9 +36,7 @@ import { join } from 'node:path';
 
 import react from '@vitejs/plugin-react';
 import { playwright } from 'vite-plus/test/browser-playwright';
-import { defineConfig, lazyPlugins } from 'vite-plus';
-
-import type { UserConfigFn } from 'vite-plus';
+import { defineConfig, type UserConfigFn, lazyPlugins } from 'vite-plus';
 
 export default defineConfig(<UserConfigFn>(((() => {
   return {