diff --git a/src/index.ts b/src/index.ts
index 33346d4..3780624 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -43,9 +43,11 @@ const deepmerge = createDeepMerge({
   }
 });
 
-const fileExists = (path: string) => fs.promises.access(path, fs.constants.F_OK)
-  .then(() => true)
-  .catch(() => false);
+function fileExists(path: string) {
+  return fs.promises.access(path, fs.constants.F_OK)
+    .then(() => true)
+    .catch(() => false);
+}
 
 function swc(options: PluginOptions = {}): RollupPlugin {
   const filter = createFilter(
@@ -116,9 +118,6 @@ function swc(options: PluginOptions = {}): RollupPlugin {
           ? {}
           : getOptions(this, dirname(id), options.tsconfig);
 
-      // TODO: SWC is about to add "preserve" jsx
-      // https://github.com/swc-project/swc/pull/5661
-      // Respect "preserve" after swc adds the support
       const useReact17NewTransform = tsconfigOptions.jsx === 'react-jsx' || tsconfigOptions.jsx === 'react-jsxdev';
 
       const swcOptionsFromTsConfig: SwcOptions = {
diff --git a/src/options.ts b/src/options.ts
index 0dd5fc7..32444a9 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -9,11 +9,11 @@ import { fileURLToPath } from 'node:url';
 
 const cache = new Map<string, TsConfigJson.CompilerOptions>();
 
-export const getOptions = (
+export function getOptions(
   ctx: TransformPluginContext,
   cwd: string,
   tsconfig?: string
-) => {
+) {
   const cacheKey = `${cwd}:${tsconfig ?? 'undefined'}`;
 
   if (cache.has(cacheKey)) {
@@ -57,9 +57,9 @@ export const getOptions = (
 
   cache.set(cacheKey, compilerOptions);
   return compilerOptions;
-};
+}
 
-export const checkIsLegacyTypeScript = () => {
+export function checkIsLegacyTypeScript() {
   try {
     // @ts-expect-error -- It's required to using 'import.mtea.url' but i don't want to change the tsconfig.
     const tsPath = resolve('typescript/package.json', import.meta.url);
@@ -70,4 +70,4 @@ export const checkIsLegacyTypeScript = () => {
   } catch {
     return false;
   }
-};
+}
diff --git a/test/index.ts b/test/index.ts
index b99c0a1..eaf90d6 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -27,7 +27,7 @@ import { async as ezspawn } from '@jsdevtools/ez-spawn';
 chai.should();
 chai.use(jestSnapshotPlugin());
 
-const rollupInvriant = (v: RollupOutput['output'][number] | undefined | null) => {
+function rollupInvriant(v: RollupOutput['output'][number] | undefined | null) {
   if (v == null) {
     throw new Error('Invariant failed');
   }
@@ -35,10 +35,9 @@ const rollupInvriant = (v: RollupOutput['output'][number] | undefined | null) =>
     throw new Error('Non rollup output module found!');
   }
   return v;
-};
+}
 
-const build = async (
-  rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4,
+async function build(rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4,
   options?: PluginOptions,
   {
     input = './index.js',
@@ -54,8 +53,7 @@ const build = async (
     sourcemap?: boolean,
     dir?: string,
     external?: ExternalOption
-  } = {}
-) => {
+  } = {}) {
   const build = await rollupImpl({
     input: (() => {
       if (typeof input === 'string') {
@@ -79,27 +77,25 @@ const build = async (
   });
   const { output } = await build.generate({ format: 'esm', sourcemap });
   return output;
-};
+}
 
-const runMinify = async (
-  rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4,
+async function runMinify(rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4,
   options: JsMinifyOptions,
   {
     input = './index.js',
     otherRollupPlugins = [],
     sourcemap = false,
     dir = '.'
-  }
-) => {
+  }) {
   const build = await rollupImpl({
     input: [...(Array.isArray(input) ? input : [input])].map((v) => path.resolve(dir, v)),
     plugins: [...otherRollupPlugins, minify(options)] as any
   });
   const { output } = await build.generate({ format: 'esm', sourcemap });
   return output;
-};
+}
 
-const tests = (rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4, isolateDir: string) => {
+function tests(rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4, isolateDir: string) {
   const fixture = async (fixtureName: string) => {
     const fixtureDir = path.join(__dirname, 'fixtures', fixtureName);
     const testDir = path.join(isolateDir, 'rollup-plugin-swc', fixtureName);
@@ -392,7 +388,7 @@ const tests = (rollupImpl: typeof rollup2 | typeof rollup3 | typeof rollup4, iso
       { input: './index.ts', dir }
     ))[0].code.should.matchSnapshot();
   });
-};
+}
 
 describe('rollup-plugin-swc3', () => {
   const ramDiskPath = create.sync('rolluppluginswc3test', 64 * 1024 * 1024, { quiet: false });