fix: external type only packages @types/*

Author: Kalven Schraut <kalvens@rtvision.com>
Ref #755

closes #755

Author: kalvenschraut

src/features/dep.ts

@@ -1,7 +1,7 @@
 import { isBuiltin } from 'node:module'
 import { blue, underline, yellow } from 'ansis'
 import { createDebug } from 'obug'
-import { RE_NODE_MODULES } from 'rolldown-plugin-dts/filename'
+import { RE_DTS, RE_NODE_MODULES } from 'rolldown-plugin-dts/filename'
 import { and, id, importerId, include } from 'rolldown/filter'
 import { matchPattern, slash, typeAssert } from '../utils/general.ts'
 import { shimFile } from './shims.ts'
@@ -165,11 +165,17 @@ export function DepPlugin({
       }
     }
 
-    if (
-      deps &&
-      (deps.includes(id) || deps.some((dep) => id.startsWith(`${dep}/`)))
-    ) {
-      return true
+    if (deps) {
+      if (deps.includes(id) || deps.some((dep) => id.startsWith(`${dep}/`))) {
+        return true
+      }
+
+      if (importer && RE_DTS.test(importer) && !id.startsWith('@types/')) {
+        const typesName = `@types/${id.replace(/^@/, '').replaceAll('/', '__')}`
+        if (deps.includes(typesName)) {
+          return true
+        }
+      }
     }
 
     return false

tests/__snapshots__/externalize-types-foo.snap.md

@@ -0,0 +1,16 @@
+## index.d.mts
+
+```mts
+import { version } from "foo";
+export { version };
+```
+
+## index.mjs
+
+```mjs
+//#region node_modules/foo/index.js
+const version = "1.0.0";
+
+//#endregion
+export { version };
+```

tests/e2e.test.ts

@@ -748,3 +748,40 @@ describe('import.meta.glob', () => {
     expect(outputFiles.length).toBe(1)
   })
 })
+
+test('externalize @types/foo', async (context) => {
+  const node_modules = {
+    'node_modules/foo/index.js': `export const version = "1.0.0"`,
+    'node_modules/foo/package.json': JSON.stringify({
+      name: 'foo',
+      version: '1.0.0',
+      main: 'index.js',
+    }),
+
+    'node_modules/@types/foo/index.d.ts': `export const version: string`,
+    'node_modules/@types/foo/package.json': JSON.stringify({
+      name: '@types/foo',
+      version: '1.0.0',
+      types: 'index.d.ts',
+    }),
+  }
+
+  const { fileMap } = await testBuild({
+    context,
+    files: {
+      ...node_modules,
+      'index.ts': `export { version } from 'foo'`,
+      'package.json': JSON.stringify({
+        name: 'test-pkg',
+        version: '1.0.0',
+        dependencies: {
+          '@types/foo': '^1.0.0',
+        },
+      }),
+    },
+    options: { dts: true },
+  })
+
+  expect(fileMap['index.mjs']).toContain('1.0.0')
+  expect(fileMap['index.d.mts']).toContain('from "foo"')
+})