fix: type-only imports

sxzz · sxzz · commit 8fa67c1a3cf5 · 2025-04-23T16:42:21.000+08:00
closes #67
diff --git a/src/core/ast.ts b/src/core/ast.ts
@@ -14,11 +14,7 @@ export type OxcImport = (
 
 export function filterImports(program: OxcTypes.Program): OxcImport[] {
   return program.body.filter(
-    (node): node is OxcImport =>
-      (node.type === 'ImportDeclaration' ||
-        node.type === 'ExportAllDeclaration' ||
-        node.type === 'ExportNamedDeclaration') &&
-      !!node.source,
+    (node): node is OxcImport => !!('source' in node && node.source),
   )
 }
 
diff --git a/src/index.ts b/src/index.ts
@@ -173,27 +173,8 @@ export const IsolatedDecl: UnpluginInstance<Options | undefined, false> =
 
       addOutput(id, { s, imports, map })
 
-      const typeImports = program.body.filter((node): node is OxcImport => {
-        if (!('source' in node) || !node.source) return false
-        if ('importKind' in node && node.importKind === 'type') return true
-        if ('exportKind' in node && node.exportKind === 'type') return true
-
-        if (node.type === 'ImportDeclaration') {
-          return (
-            !!node.specifiers &&
-            node.specifiers.every(
-              (spec) =>
-                spec.type === 'ImportSpecifier' && spec.importKind === 'type',
-            )
-          )
-        }
-        return (
-          node.type === 'ExportNamedDeclaration' &&
-          node.specifiers &&
-          node.specifiers.every((spec) => spec.exportKind === 'type')
-        )
-      })
-      for (const { source } of typeImports) {
+      const importsInDts = filterImports(program)
+      for (const { source } of importsInDts) {
         const resolved = (await resolve(context, source.value, id))?.id
         if (resolved && filter(resolved) && !outputFiles[stripExt(resolved)]) {
           let source: string
diff --git a/tests/__snapshots__/rollup/type-only.md b/tests/__snapshots__/rollup/type-only.md
@@ -0,0 +1,21 @@
+## dep.d.ts
+
+```ts
+export type Dep = "dep";
+
+```
+## main.d.ts
+
+```ts
+export { Dep } from "./dep.js";
+export declare const main = "main";
+
+```
+## main.js
+
+```js
+const main = "main";
+
+export { main };
+
+```
diff --git a/tests/fixtures/type-only/dep.ts b/tests/fixtures/type-only/dep.ts
@@ -0,0 +1 @@
+export type Dep = 'dep'
diff --git a/tests/fixtures/type-only/main.ts b/tests/fixtures/type-only/main.ts
@@ -0,0 +1,3 @@
+export type { Dep } from './dep'
+
+export const main = 'main'
diff --git a/tests/rollup.test.ts b/tests/rollup.test.ts
@@ -189,4 +189,20 @@ describe.concurrent('rollup', () => {
 
     await expectSnapshot(dist, `rollup/${dir}`, expect)
   })
+
+  test('type only imports', async ({ expect }) => {
+    const dir = 'type-only'
+    const input = path.resolve(fixtures, dir, 'main.ts')
+    const dist = path.resolve(TEST_SANDBOX_FOLDER, dir)
+
+    const bundle = await rollup({
+      input,
+      plugins: [UnpluginIsolatedDecl(), Oxc()],
+      logLevel: 'silent',
+    })
+
+    await bundle.write({ dir: dist })
+
+    await expectSnapshot(dist, `rollup/${dir}`, expect)
+  })
 })

Original file line number	Diff line number	Diff line change
`@@ -14,11 +14,7 @@ export type OxcImport = (`
`14`	`14`
`15`	`15`	`export function filterImports(program: OxcTypes.Program): OxcImport[] {`
`16`	`16`	`return program.body.filter(`
`17`		`- (node): node is OxcImport =>`
`18`		`- (node.type === 'ImportDeclaration' \|\|`
`19`		`- node.type === 'ExportAllDeclaration' \|\|`
`20`		`- node.type === 'ExportNamedDeclaration') &&`
`21`		`- !!node.source,`
	`17`	`+ (node): node is OxcImport => !!('source' in node && node.source),`
`22`	`18`	`)`
`23`	`19`	`}`
`24`	`20`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+export type { Dep } from './dep'`
	`2`	`+`
	`3`	`+export const main = 'main'`