feat: support for self-referencing (#16068)

packages/vite/src/node/plugins/resolve.ts

@@ -735,7 +735,19 @@ export function tryNodeResolve(
     basedir = root
   }
 
-  const pkg = resolvePackageData(pkgId, basedir, preserveSymlinks, packageCache)
+  let selfPkg = null
+  if (!isBuiltin(id) && !id.includes('\0') && bareImportRE.test(id)) {
+    // check if it's a self reference dep.
+    const selfPackageData = findNearestPackageData(basedir, packageCache)
+    selfPkg =
+      selfPackageData?.data.exports && selfPackageData?.data.name === pkgId
+        ? selfPackageData
+        : null
+  }
+
+  const pkg =
+    selfPkg ||
+    resolvePackageData(pkgId, basedir, preserveSymlinks, packageCache)
   if (!pkg) {
     // if import can't be found, check if it's an optional peer dep.
     // if so, we can resolve to a special id that errors only when imported.

playground/nested-deps/__tests__/nested-deps.spec.ts

@@ -14,4 +14,5 @@ test('handle nested package', async () => {
   // expect(await page.textContent('.nested-e')).toBe('1')
 
   expect(await page.textContent('.absolute-f')).toBe('F@2.0.0')
+  expect(await page.textContent('.self-referencing')).toBe('true')
 })

playground/nested-deps/index.html

@@ -24,6 +24,9 @@ <h2>exclude dependency of pre-bundled dependency</h2>
 
 <h2>absolute dependency path: <span class="absolute-f"></span></h2>
 
+<h2>self referencing</h2>
+<pre class="self-referencing"></pre>
+
 <script type="module">
   import A from '@vitejs/test-package-a'
   import B, { A as nestedA } from '@vitejs/test-package-b'
@@ -32,6 +35,7 @@ <h2>absolute dependency path: <span class="absolute-f"></span></h2>
   import D, { nestedD } from '@vitejs/test-package-d'
   // import { testExcluded } from '@vitejs/test-package-e'
   import F from '__F_ABSOLUTE_PACKAGE_PATH__'
+  import { isSelfReference } from '@vitejs/self-referencing/test'
 
   text('.a', A)
   text('.b', B)
@@ -47,6 +51,8 @@ <h2>absolute dependency path: <span class="absolute-f"></span></h2>
 
   text('.absolute-f', F)
 
+  text('.self-referencing', isSelfReference)
+
   function text(sel, text) {
     document.querySelector(sel).textContent = text
   }

playground/nested-deps/package.json

@@ -15,6 +15,7 @@
     "@vitejs/test-package-c": "link:./test-package-c",
     "@vitejs/test-package-d": "link:./test-package-d",
     "@vitejs/test-package-e": "link:./test-package-e",
-    "@vitejs/test-package-f": "link:./test-package-f"
+    "@vitejs/test-package-f": "link:./test-package-f",
+    "@vitejs/self-referencing": "link:../self-referencing"
   }
 }

playground/self-referencing/index.js

@@ -0,0 +1 @@
+export const isSelfReference = true

playground/self-referencing/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@vitejs/self-referencing",
+  "type": "module",
+  "exports": {
+    ".": "./index.js",
+    "./test": "./test/index.js"
+  }
+}

playground/self-referencing/test/index.js

@@ -0,0 +1 @@
+export { isSelfReference } from '@vitejs/self-referencing'