feat: support check experimental decorators

package.json

@@ -31,6 +31,7 @@
   "author": "",
   "license": "MIT",
   "dependencies": {
+    "@dual-bundle/import-meta-resolve": "^4.1.0",
     "@fastify/deepmerge": "^2.0.0",
     "@rollup/pluginutils": "^5.1.0",
     "get-tsconfig": "^4.8.0",

src/index.ts

@@ -1,5 +1,4 @@
 import type { Plugin as RollupPlugin } from 'rollup';
-
 import fs from 'node:fs';
 import process from 'node:process';
 import { extname, resolve, dirname, join } from 'node:path';
@@ -15,7 +14,7 @@ import {
 } from '@swc/core';
 import createDeepMerge from '@fastify/deepmerge';
 
-import { getOptions } from './options';
+import { getOptions, getEnableExperimentalDecorators } from './options';
 
 import type { Plugin as VitePlugin } from 'vite';
 
@@ -116,6 +115,8 @@ function swc(options: PluginOptions = {}): RollupPlugin {
           ? {}
           : getOptions(this, dirname(id), options.tsconfig);
 
+      const enableExperimentalDecorators = getEnableExperimentalDecorators(this, isTypeScript, 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
@@ -127,7 +128,7 @@ function swc(options: PluginOptions = {}): RollupPlugin {
           parser: {
             syntax: isTypeScript ? 'typescript' : 'ecmascript',
             [isTypeScript ? 'tsx' : 'jsx']: isTypeScript ? isTsx : isJsx,
-            decorators: tsconfigOptions.experimentalDecorators
+            decorators: enableExperimentalDecorators || tsconfigOptions.experimentalDecorators
           },
           transform: {
             decoratorMetadata: tsconfigOptions.emitDecoratorMetadata,
@@ -139,7 +140,8 @@ function swc(options: PluginOptions = {}): RollupPlugin {
               pragma: tsconfigOptions.jsxFactory,
               pragmaFrag: tsconfigOptions.jsxFragmentFactory,
               development: tsconfigOptions.jsx === 'react-jsxdev' ? true : undefined
-            }
+            },
+            decoratorVersion: enableExperimentalDecorators ? '2022-03' : '2021-12'
           },
           target: tsconfigOptions.target?.toLowerCase() as JscTarget | undefined,
           baseUrl: tsconfigOptions.baseUrl,

src/options.ts

@@ -1,11 +1,16 @@
 import { getTsconfig, parseTsconfig } from 'get-tsconfig';
+import { resolve } from '@dual-bundle/import-meta-resolve';
 import path from 'node:path';
+import fs from 'node:fs';
 
 import type { TsConfigJson } from 'get-tsconfig';
 import type { TransformPluginContext } from 'rollup';
+import { fileURLToPath } from 'node:url';
 
 const cache = new Map<string, TsConfigJson.CompilerOptions>();
 
+const tsExperimentCache = new Map<string, boolean>();
+
 export const getOptions = (
   ctx: TransformPluginContext,
   cwd: string,
@@ -55,3 +60,32 @@ export const getOptions = (
   cache.set(cacheKey, compilerOptions);
   return compilerOptions;
 };
+
+export const getEnableExperimentalDecorators = (
+  ctx: TransformPluginContext, isTypeScript: boolean, cwd: string, key?: string | boolean
+) => {
+  if (!isTypeScript) return false;
+  const cacheKey = `${cwd}:${key ?? 'undefined'}`;
+  if (tsExperimentCache.has(cacheKey)) {
+    return tsExperimentCache.get(cacheKey) ?? false;
+  }
+  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);
+    const { version } = JSON.parse(fs.readFileSync(fileURLToPath(tsPath), 'utf-8'));
+    const [major] = version.split('.');
+    // Only enable experimental decorators for TypeScript 5+
+    if (+major >= 5) {
+      tsExperimentCache.set(cacheKey, true);
+      return true;
+    }
+    tsExperimentCache.set(cacheKey, false);
+    return false;
+  } catch {
+    ctx.warn({
+      message: 'Failed to find TypeScript. Please check if TypeScript has been installed.',
+      pluginCode: 'SWC_TYPESCRIPT_NOT_EXISTS'
+    });
+    return false;
+  }
+};