feat: dynamic query svelte version

fix #299

examples/vue/components/BothScripts.vue

@@ -28,6 +28,12 @@ defineExpose({ inc })
 <script lang="ts">
 // do not use defineComponent
 
+export interface BothScriptsProps {
+  /** comment */
+  tag: string
+  count: number
+}
+
 export default {
   name: 'BothScripts',
   customOptions: {}

package.json

@@ -62,8 +62,10 @@
     "@rollup/pluginutils": "^5.1.0",
     "@volar/typescript": "^2.3.4",
     "@vue/language-core": "2.0.19",
+    "compare-versions": "^6.1.1",
     "debug": "^4.3.5",
     "kolorist": "^1.8.0",
+    "local-pkg": "^0.5.0",
     "magic-string": "^0.30.10",
     "vue-tsc": "2.0.19"
   },

src/resolvers/svelte.ts

@@ -1,20 +1,40 @@
 import { relative } from 'node:path'
 
+import { getPackageInfoSync, resolveModule } from 'local-pkg'
+import { compare } from 'compare-versions'
+
 import type { Resolver } from '../types'
 
 const svelteRE = /\.svelte$/
 
+let lowerVersion: boolean
+
+function querySvelteVersion() {
+  if (typeof lowerVersion === 'boolean') return
+
+  try {
+    const version =
+      getPackageInfoSync('svelte')?.version ??
+      getPackageInfoSync('svelte', { paths: [resolveModule('svelte') || process.cwd()] })?.version
+    lowerVersion = version ? compare(version, '4.0.0', '<') : false
+  } catch {
+    lowerVersion = false
+  }
+}
+
 export function SvelteResolver(): Resolver {
   return {
     name: 'svelte',
     supports(id) {
       return svelteRE.test(id)
     },
     transform({ id, root }) {
+      querySvelteVersion()
+
       return [
         {
           path: relative(root, `${id}.d.ts`),
-          content: "export { SvelteComponentTyped as default } from 'svelte';\n"
+          content: `export { ${lowerVersion ? 'SvelteComponentTyped' : 'SvelteComponent'} as default } from 'svelte';\n`
         }
       ]
     }