fix: don't add . when autoAddExts is disabled

Author: sxzz

src/core/utils.ts

@@ -69,6 +69,6 @@ export function guessSuffix(id: string, resolved: string): string {
     .extname(resolved)
     .slice(1)
     .replace(/^([cm]?)ts/, (_, $1) => `${$1}js`)
-  suffix += `.${ext}`
+  if (ext) suffix += `.${ext}`
   return suffix
 }

tests/__snapshots__/rollup.test.ts.snap

@@ -1,5 +1,38 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
+exports[`rollup > autoAddExts 1`] = `
+"// main.js
+function Component() {
+  return /* @__PURE__ */ React.createElement("div", null, "I'm a div in a tsx component!");
+}
+
+function hello(s) {
+  return "hello" + s;
+}
+let c = Component;
+let num = 1;
+
+export { c, hello, num };
+
+// temp/component.d.ts
+export declare function Component(): React.JSX.Element;
+
+// temp/main.d.ts
+import { type Num } from '../temp/types.js';
+export type Str = string;
+export declare function hello(s: Str): Str;
+export declare let c: React.JSX.Element;
+export declare let num: Num;
+
+// temp/types.d.ts
+import type { Num2 } from '../temp/types2.js';
+export type Num = Num2;
+
+// temp/types2.d.ts
+export type Num2 = number;
+"
+`;
+
 exports[`rollup > custom rewriter 1`] = `
 "// index.d.ts
 export type * from './test.js';
@@ -30,14 +63,14 @@ export { c, hello, num };
 export declare function Component(): React.JSX.Element;
 
 // temp/main.d.ts
-import { type Num } from '../temp/types.js';
+import { type Num } from '../temp/types';
 export type Str = string;
 export declare function hello(s: Str): Str;
 export declare let c: React.JSX.Element;
 export declare let num: Num;
 
 // temp/types.d.ts
-import type { Num2 } from '../temp/types2.js';
+import type { Num2 } from '../temp/types2';
 export type Num = Num2;
 
 // temp/types2.d.ts

tests/rollup.test.ts

@@ -15,6 +15,20 @@ describe('rollup', () => {
     const dir = 'basic'
     const input = path.resolve(fixtures, dir, 'main.ts')
 
+    const bundle = await rollup({
+      input,
+      plugins: [UnpluginIsolatedDecl({ extraOutdir: 'temp' }), esbuild()],
+      logLevel: 'silent',
+    })
+    const result = await bundle.generate({})
+
+    expect(outputToSnapshot(result.output)).toMatchSnapshot()
+  })
+
+  test('autoAddExts', async () => {
+    const dir = 'basic'
+    const input = path.resolve(fixtures, dir, 'main.ts')
+
     const bundle = await rollup({
       input,
       plugins: [