From 3aba00766fb2d0e91ba699e1468ed72d5ba89311 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 16:39:12 +0900
Subject: [PATCH 01/15] test: add dynamic import test

---
 playground/config/__tests__/config.spec.ts    | 21 +++++++++++++++++++
 .../packages/entry/vite.config.dynamic.ts     |  6 ++++++
 .../config/packages/siblings/dynamic.js       |  1 +
 playground/config/packages/siblings/ok.js     |  1 +
 4 files changed, 29 insertions(+)
 create mode 100644 playground/config/packages/entry/vite.config.dynamic.ts
 create mode 100644 playground/config/packages/siblings/dynamic.js
 create mode 100644 playground/config/packages/siblings/ok.js

diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index b4a665e87e41e8..ece1e1ff83ad4c 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -47,3 +47,24 @@ it.runIf(isImportAttributesSupported)(
     `)
   },
 )
+
+it('dynamic import with non-static arguments', async () => {
+  const { config } = (await loadConfigFromFile(
+    { command: 'serve', mode: 'development' },
+    resolve(__dirname, '../packages/entry/vite.config.dynamic.ts'),
+  )) as any
+  expect(await config.rawImport('../siblings/ok.js')).toMatchInlineSnapshot(`
+    {
+      "default": "ok",
+    }
+  `)
+  expect(await config.rawImport('@vite/test-config-plugin-module-condition'))
+    .toMatchInlineSnapshot(`
+    {
+      "default": "import condition",
+    }
+  `)
+  await expect(() => config.siblingsDynamic('./ok.js')).rejects.toThrow(
+    'Cannot find module',
+  )
+})
diff --git a/playground/config/packages/entry/vite.config.dynamic.ts b/playground/config/packages/entry/vite.config.dynamic.ts
new file mode 100644
index 00000000000000..ed7601c4870222
--- /dev/null
+++ b/playground/config/packages/entry/vite.config.dynamic.ts
@@ -0,0 +1,6 @@
+import siblingsDynamic from '../siblings/dynamic.js'
+
+export default {
+  rawImport: (id: string) => import(id),
+  siblingsDynamic,
+}
diff --git a/playground/config/packages/siblings/dynamic.js b/playground/config/packages/siblings/dynamic.js
new file mode 100644
index 00000000000000..de0315ff8d79e0
--- /dev/null
+++ b/playground/config/packages/siblings/dynamic.js
@@ -0,0 +1 @@
+export default (id) => import(id)
diff --git a/playground/config/packages/siblings/ok.js b/playground/config/packages/siblings/ok.js
new file mode 100644
index 00000000000000..60c71f346d9a3e
--- /dev/null
+++ b/playground/config/packages/siblings/ok.js
@@ -0,0 +1 @@
+export default 'ok'

From df9814934a037f8ae510d2abfef00c4440aeb21a Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 16:46:00 +0900
Subject: [PATCH 02/15] wip: transformViteConfigDynamicImport

---
 packages/vite/src/node/config.ts | 77 ++++++++++++++++++++++++++++++++
 packages/vite/src/node/index.ts  |  1 +
 2 files changed, 78 insertions(+)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index e38e5b5959809b..74a66da399db08 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -10,6 +10,8 @@ import type { Alias, AliasOptions } from 'dep-types/alias'
 import aliasPlugin from '@rollup/plugin-alias'
 import { build } from 'esbuild'
 import type { RollupOptions } from 'rollup'
+import { init, parse } from 'es-module-lexer'
+import MagicString from 'magic-string'
 import { withTrailingSlash } from '../shared/utils'
 import {
   CLIENT_ENTRY,
@@ -1220,6 +1222,80 @@ async function bundleConfigFile(
   }
 }
 
+async function transformViteConfigDynamicImport(
+  text: string,
+  importer: string,
+): Promise<string> {
+  if (!/import\s*\(/.test(text)) {
+    return text
+  }
+  await init
+  const [imports] = parse(text)
+  const output = new MagicString(text)
+  for (const imp of imports) {
+    if (imp.d >= 0 && typeof imp.n === 'undefined') {
+      // dynamic import should be resolved relative to the original file but
+      // that was never the case so here we're doing the same to resolve it from current config file.
+      output.update(
+        imp.ss,
+        imp.d,
+        `__vite_config_import_helper__.bind(null, ${JSON.stringify(importer)})`,
+      )
+    }
+  }
+  if (output.hasChanged()) {
+    const vitePath = pathToFileURL(
+      path.resolve(
+        _require.resolve('vite/package.json'),
+        '../dist/node/index.js',
+      ),
+    ).href
+    output.prepend(
+      `import { __vite_config_import_helper__ } from ${JSON.stringify(vitePath)};`,
+    )
+    text = output.toString()
+  }
+  return text
+}
+
+export async function __vite_config_import_helper__(
+  importer: string,
+  id: string,
+): Promise<unknown> {
+  let resolved: string
+  if (isBuiltin(id) || id[0] === '/') {
+    resolved = id
+  } else if (id[0] === '.') {
+    resolved = path.resolve(path.dirname(importer), id)
+  } else {
+    const result = tryNodeResolve(
+      id,
+      importer,
+      {
+        root: path.dirname(importer),
+        isBuild: true,
+        isProduction: true,
+        preferRelative: false,
+        tryIndex: true,
+        mainFields: [],
+        conditions: [],
+        overrideConditions: ['node'],
+        dedupe: [],
+        extensions: DEFAULT_EXTENSIONS,
+        preserveSymlinks: false,
+        packageCache: new Map(),
+        isRequire: false,
+      },
+      false,
+    )
+    if (!result) {
+      throw new Error(`Failed to resolve dynamic import '${id}'`)
+    }
+    resolved = result.id
+  }
+  return import(resolved)
+}
+
 interface NodeModuleWithCompile extends NodeModule {
   _compile(code: string, filename: string): any
 }
@@ -1234,6 +1310,7 @@ async function loadConfigFromBundledFile(
   // with --experimental-loader themselves, we have to do a hack here:
   // write it to disk, load it with native Node ESM, then delete the file.
   if (isESM) {
+    bundledCode = await transformViteConfigDynamicImport(bundledCode, fileName)
     const fileBase = `${fileName}.timestamp-${Date.now()}-${Math.random()
       .toString(16)
       .slice(2)}`
diff --git a/packages/vite/src/node/index.ts b/packages/vite/src/node/index.ts
index 3d17f8737379d6..9e9f341de1e705 100644
--- a/packages/vite/src/node/index.ts
+++ b/packages/vite/src/node/index.ts
@@ -7,6 +7,7 @@ export {
   loadConfigFromFile,
   resolveConfig,
   sortUserPlugins,
+  __vite_config_import_helper__,
 } from './config'
 export { createServer } from './server'
 export { preview } from './preview'

From 729169871fc6b8de01cc4e2875c4b95383e6687f Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 16:55:04 +0900
Subject: [PATCH 03/15] fix: use `data:` imports from
 https://github.com/vitejs/vite/issues/9470

---
 packages/vite/src/node/config.ts | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 74a66da399db08..e451a2b1806b5f 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1309,18 +1309,18 @@ async function loadConfigFromBundledFile(
   // for esm, before we can register loaders without requiring users to run node
   // with --experimental-loader themselves, we have to do a hack here:
   // write it to disk, load it with native Node ESM, then delete the file.
+  // convert to base64, load it with native Node ESM.
   if (isESM) {
     bundledCode = await transformViteConfigDynamicImport(bundledCode, fileName)
-    const fileBase = `${fileName}.timestamp-${Date.now()}-${Math.random()
-      .toString(16)
-      .slice(2)}`
-    const fileNameTmp = `${fileBase}.mjs`
-    const fileUrl = `${pathToFileURL(fileBase)}.mjs`
-    await fsp.writeFile(fileNameTmp, bundledCode)
     try {
-      return (await import(fileUrl)).default
-    } finally {
-      fs.unlink(fileNameTmp, () => {}) // Ignore errors
+      return (
+        await import(
+          'data:text/javascript;base64,' +
+            Buffer.from(bundledCode).toString('base64')
+        )
+      ).default
+    } catch (e) {
+      throw new Error(`${e.message} at ${fileName}`)
     }
   }
   // for cjs, we can register a custom loader via `_require.extensions`

From 9ac9efaacc7574fa8e54fce810988bee8f2d55f2 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 17:06:44 +0900
Subject: [PATCH 04/15] chore: comment

---
 playground/config/__tests__/config.spec.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index ece1e1ff83ad4c..aec79e0f876b2b 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -64,6 +64,8 @@ it('dynamic import with non-static arguments', async () => {
       "default": "import condition",
     }
   `)
+  // importing "./ok.js" inside "siblings/dynamic.js" should resolve to "siblings/ok.js"
+  // but this case has never been supported.
   await expect(() => config.siblingsDynamic('./ok.js')).rejects.toThrow(
     'Cannot find module',
   )

From a12dedba68986b83267377ea1e75e66c33d705d3 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 17:11:20 +0900
Subject: [PATCH 05/15] chore: comment

---
 packages/vite/src/node/config.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index e451a2b1806b5f..5c885924c6954e 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1226,6 +1226,7 @@ async function transformViteConfigDynamicImport(
   text: string,
   importer: string,
 ): Promise<string> {
+  // replace `import(anything)` with `__vite_config_import_helper__.bind(null, importer)(anything)`
   if (!/import\s*\(/.test(text)) {
     return text
   }

From 34f831fd577cd263e59ed9d1a99c4273bff7524b Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 17:57:41 +0900
Subject: [PATCH 06/15] test: more tests

---
 packages/vite/src/node/config.ts              |  1 +
 playground/config/__tests__/config.spec.ts    | 19 ++++++++++++++++++-
 .../packages/entry/vite.config.dynamic.ts     |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 5c885924c6954e..c8ea2138be31b7 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1245,6 +1245,7 @@ async function transformViteConfigDynamicImport(
     }
   }
   if (output.hasChanged()) {
+    // TODO: we could also simply inject via globalThis?
     const vitePath = pathToFileURL(
       path.resolve(
         _require.resolve('vite/package.json'),
diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index aec79e0f876b2b..e7213352c82fa9 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -48,25 +48,42 @@ it.runIf(isImportAttributesSupported)(
   },
 )
 
-it('dynamic import with non-static arguments', async () => {
+it('dynamic import', async () => {
   const { config } = (await loadConfigFromFile(
     { command: 'serve', mode: 'development' },
     resolve(__dirname, '../packages/entry/vite.config.dynamic.ts'),
   )) as any
+  expect(await config.knownImport()).toMatchInlineSnapshot(`
+    {
+      "default": "ok",
+    }
+  `)
   expect(await config.rawImport('../siblings/ok.js')).toMatchInlineSnapshot(`
     {
       "default": "ok",
     }
   `)
+  // two are different since one is bundled but the other is from node
+  expect(await config.knownImport()).not.toBe(
+    await config.rawImport('../siblings/ok.js'),
+  )
+
   expect(await config.rawImport('@vite/test-config-plugin-module-condition'))
     .toMatchInlineSnapshot(`
     {
       "default": "import condition",
     }
   `)
+
   // importing "./ok.js" inside "siblings/dynamic.js" should resolve to "siblings/ok.js"
   // but this case has never been supported.
   await expect(() => config.siblingsDynamic('./ok.js')).rejects.toThrow(
     'Cannot find module',
   )
+
+  await expect(() =>
+    config.siblingsDynamic('no-such-module'),
+  ).rejects.toMatchInlineSnapshot(
+    `[Error: Failed to resolve dynamic import 'no-such-module']`,
+  )
 })
diff --git a/playground/config/packages/entry/vite.config.dynamic.ts b/playground/config/packages/entry/vite.config.dynamic.ts
index ed7601c4870222..c9983dce4cac5f 100644
--- a/playground/config/packages/entry/vite.config.dynamic.ts
+++ b/playground/config/packages/entry/vite.config.dynamic.ts
@@ -1,6 +1,7 @@
 import siblingsDynamic from '../siblings/dynamic.js'
 
 export default {
+  knownImport: () => import('../siblings/ok.js'),
   rawImport: (id: string) => import(id),
   siblingsDynamic,
 }

From 3df58a7275933f9d1a247cd3cd36eda335f84281 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 18:08:31 +0900
Subject: [PATCH 07/15] chore: hide dts

---
 packages/vite/src/node/index.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/vite/src/node/index.ts b/packages/vite/src/node/index.ts
index 9e9f341de1e705..814715f12552e6 100644
--- a/packages/vite/src/node/index.ts
+++ b/packages/vite/src/node/index.ts
@@ -7,7 +7,6 @@ export {
   loadConfigFromFile,
   resolveConfig,
   sortUserPlugins,
-  __vite_config_import_helper__,
 } from './config'
 export { createServer } from './server'
 export { preview } from './preview'
@@ -20,6 +19,11 @@ export { fetchModule } from './ssr/fetchModule'
 export type { FetchModuleOptions } from './ssr/fetchModule'
 export * from './publicUtils'
 
+// hide it from dts
+/** @internal */
+export const __vite_config_import_helper__ = __tmp_vite_config_import_helper__
+import { __vite_config_import_helper__ as __tmp_vite_config_import_helper__ } from './config'
+
 // additional types
 export type {
   AppType,

From 972ce064f2ee66946fb4723bf10d4091eba2e9c8 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 18:20:52 +0900
Subject: [PATCH 08/15] refactor: minor

---
 packages/vite/src/node/config.ts | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index c8ea2138be31b7..d80151333ca552 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1226,7 +1226,7 @@ async function transformViteConfigDynamicImport(
   text: string,
   importer: string,
 ): Promise<string> {
-  // replace `import(anything)` with `__vite_config_import_helper__.bind(null, importer)(anything)`
+  // replace `import(anything)` with `__vite_config_import__(anything)`
   if (!/import\s*\(/.test(text)) {
     return text
   }
@@ -1237,15 +1237,11 @@ async function transformViteConfigDynamicImport(
     if (imp.d >= 0 && typeof imp.n === 'undefined') {
       // dynamic import should be resolved relative to the original file but
       // that was never the case so here we're doing the same to resolve it from current config file.
-      output.update(
-        imp.ss,
-        imp.d,
-        `__vite_config_import_helper__.bind(null, ${JSON.stringify(importer)})`,
-      )
+      output.update(imp.ss, imp.d, `__vite_config_import__`)
     }
   }
   if (output.hasChanged()) {
-    // TODO: we could also simply inject via globalThis?
+    // TODO: could we simply inject it via globalThis?
     const vitePath = pathToFileURL(
       path.resolve(
         _require.resolve('vite/package.json'),
@@ -1253,7 +1249,8 @@ async function transformViteConfigDynamicImport(
       ),
     ).href
     output.prepend(
-      `import { __vite_config_import_helper__ } from ${JSON.stringify(vitePath)};`,
+      `import { __vite_config_import_helper__ } from ${JSON.stringify(vitePath)};` +
+        `const __vite_config_import__ = (id) => __vite_config_import_helper__(${JSON.stringify(importer)}, id);`,
     )
     text = output.toString()
   }

From 13b72d073a4ca4560850dc9142574f44e0f84bfc Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 18:26:50 +0900
Subject: [PATCH 09/15] fix: more pathToFileURL

---
 packages/vite/src/node/config.ts           | 4 ++--
 playground/config/__tests__/config.spec.ts | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index d80151333ca552..5c246d6fb5e08c 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1265,7 +1265,7 @@ export async function __vite_config_import_helper__(
   if (isBuiltin(id) || id[0] === '/') {
     resolved = id
   } else if (id[0] === '.') {
-    resolved = path.resolve(path.dirname(importer), id)
+    resolved = pathToFileURL(path.resolve(path.dirname(importer), id)).href
   } else {
     const result = tryNodeResolve(
       id,
@@ -1290,7 +1290,7 @@ export async function __vite_config_import_helper__(
     if (!result) {
       throw new Error(`Failed to resolve dynamic import '${id}'`)
     }
-    resolved = result.id
+    resolved = pathToFileURL(result.id).href
   }
   return import(resolved)
 }
diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index e7213352c82fa9..6d79fba0f5ea0b 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -82,7 +82,7 @@ it('dynamic import', async () => {
   )
 
   await expect(() =>
-    config.siblingsDynamic('no-such-module'),
+    config.rawImport('no-such-module'),
   ).rejects.toMatchInlineSnapshot(
     `[Error: Failed to resolve dynamic import 'no-such-module']`,
   )

From 6aa9f18303862d7112aaefc007add05d83dd4871 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 18:35:31 +0900
Subject: [PATCH 10/15] refactor: reuse more

---
 packages/vite/src/node/config.ts | 91 ++++++++++++++------------------
 1 file changed, 39 insertions(+), 52 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 5c246d6fb5e08c..a577c959bdb65f 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1070,6 +1070,34 @@ export async function loadConfigFromFile(
   }
 }
 
+function createNodeResolveForConfigFile(
+  fileName: string,
+  packageCache: PackageCache,
+) {
+  return (id: string, importer: string, isRequire: boolean) => {
+    return tryNodeResolve(
+      id,
+      importer,
+      {
+        root: path.dirname(fileName),
+        isBuild: true,
+        isProduction: true,
+        preferRelative: false,
+        tryIndex: true,
+        mainFields: [],
+        conditions: [],
+        overrideConditions: ['node'],
+        dedupe: [],
+        extensions: DEFAULT_EXTENSIONS,
+        preserveSymlinks: false,
+        packageCache,
+        isRequire,
+      },
+      false,
+    )?.id
+  }
+}
+
 async function bundleConfigFile(
   fileName: string,
   isESM: boolean,
@@ -1100,32 +1128,10 @@ async function bundleConfigFile(
         name: 'externalize-deps',
         setup(build) {
           const packageCache = new Map()
-          const resolveByViteResolver = (
-            id: string,
-            importer: string,
-            isRequire: boolean,
-          ) => {
-            return tryNodeResolve(
-              id,
-              importer,
-              {
-                root: path.dirname(fileName),
-                isBuild: true,
-                isProduction: true,
-                preferRelative: false,
-                tryIndex: true,
-                mainFields: [],
-                conditions: [],
-                overrideConditions: ['node'],
-                dedupe: [],
-                extensions: DEFAULT_EXTENSIONS,
-                preserveSymlinks: false,
-                packageCache,
-                isRequire,
-              },
-              false,
-            )?.id
-          }
+          const resolveByViteResolver = createNodeResolveForConfigFile(
+            fileName,
+            packageCache,
+          )
 
           // externalize bare imports
           build.onResolve(
@@ -1235,8 +1241,6 @@ async function transformViteConfigDynamicImport(
   const output = new MagicString(text)
   for (const imp of imports) {
     if (imp.d >= 0 && typeof imp.n === 'undefined') {
-      // dynamic import should be resolved relative to the original file but
-      // that was never the case so here we're doing the same to resolve it from current config file.
       output.update(imp.ss, imp.d, `__vite_config_import__`)
     }
   }
@@ -1248,6 +1252,8 @@ async function transformViteConfigDynamicImport(
         '../dist/node/index.js',
       ),
     ).href
+    // dynamic import should be resolved relative to the original file but
+    // that was never the case so here we're doing the same to resolve it from current config file.
     output.prepend(
       `import { __vite_config_import_helper__ } from ${JSON.stringify(vitePath)};` +
         `const __vite_config_import__ = (id) => __vite_config_import_helper__(${JSON.stringify(importer)}, id);`,
@@ -1267,30 +1273,12 @@ export async function __vite_config_import_helper__(
   } else if (id[0] === '.') {
     resolved = pathToFileURL(path.resolve(path.dirname(importer), id)).href
   } else {
-    const result = tryNodeResolve(
-      id,
-      importer,
-      {
-        root: path.dirname(importer),
-        isBuild: true,
-        isProduction: true,
-        preferRelative: false,
-        tryIndex: true,
-        mainFields: [],
-        conditions: [],
-        overrideConditions: ['node'],
-        dedupe: [],
-        extensions: DEFAULT_EXTENSIONS,
-        preserveSymlinks: false,
-        packageCache: new Map(),
-        isRequire: false,
-      },
-      false,
-    )
+    const resolver = createNodeResolveForConfigFile(importer, new Map())
+    const result = resolver(id, importer, false)
     if (!result) {
       throw new Error(`Failed to resolve dynamic import '${id}'`)
     }
-    resolved = pathToFileURL(result.id).href
+    resolved = pathToFileURL(result).href
   }
   return import(resolved)
 }
@@ -1310,12 +1298,11 @@ async function loadConfigFromBundledFile(
   // write it to disk, load it with native Node ESM, then delete the file.
   // convert to base64, load it with native Node ESM.
   if (isESM) {
-    bundledCode = await transformViteConfigDynamicImport(bundledCode, fileName)
+    const code = await transformViteConfigDynamicImport(bundledCode, fileName)
     try {
       return (
         await import(
-          'data:text/javascript;base64,' +
-            Buffer.from(bundledCode).toString('base64')
+          'data:text/javascript;base64,' + Buffer.from(code).toString('base64')
         )
       ).default
     } catch (e) {

From d5c3a34e4858adcd00bbf62b2d1e66b6d66fd127 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Sun, 18 Aug 2024 18:37:32 +0900
Subject: [PATCH 11/15] refactor: minor

---
 packages/vite/src/node/config.ts | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index a577c959bdb65f..6b037a93bf2c0d 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1221,7 +1221,10 @@ async function bundleConfigFile(
       },
     ],
   })
-  const { text } = result.outputFiles[0]
+  let { text } = result.outputFiles[0]
+  if (isESM) {
+    text = await transformViteConfigDynamicImport(text, fileName)
+  }
   return {
     code: text,
     dependencies: result.metafile ? Object.keys(result.metafile.inputs) : [],
@@ -1232,7 +1235,6 @@ async function transformViteConfigDynamicImport(
   text: string,
   importer: string,
 ): Promise<string> {
-  // replace `import(anything)` with `__vite_config_import__(anything)`
   if (!/import\s*\(/.test(text)) {
     return text
   }
@@ -1240,6 +1242,7 @@ async function transformViteConfigDynamicImport(
   const [imports] = parse(text)
   const output = new MagicString(text)
   for (const imp of imports) {
+    // replace `import(anything)` with `__vite_config_import__(anything)`
     if (imp.d >= 0 && typeof imp.n === 'undefined') {
       output.update(imp.ss, imp.d, `__vite_config_import__`)
     }
@@ -1298,11 +1301,11 @@ async function loadConfigFromBundledFile(
   // write it to disk, load it with native Node ESM, then delete the file.
   // convert to base64, load it with native Node ESM.
   if (isESM) {
-    const code = await transformViteConfigDynamicImport(bundledCode, fileName)
     try {
       return (
         await import(
-          'data:text/javascript;base64,' + Buffer.from(code).toString('base64')
+          'data:text/javascript;base64,' +
+            Buffer.from(bundledCode).toString('base64')
         )
       ).default
     } catch (e) {

From eef58f3671e93350558d96e0a0fb47746b0e59a6 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Mon, 19 Aug 2024 18:04:07 +0900
Subject: [PATCH 12/15] refactor: use globalThis.__vite_config_import_helper__

---
 packages/vite/src/node/config.ts | 15 +++------------
 packages/vite/src/node/index.ts  |  5 -----
 2 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 6b037a93bf2c0d..7e7d4e3eebda86 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1248,25 +1248,16 @@ async function transformViteConfigDynamicImport(
     }
   }
   if (output.hasChanged()) {
-    // TODO: could we simply inject it via globalThis?
-    const vitePath = pathToFileURL(
-      path.resolve(
-        _require.resolve('vite/package.json'),
-        '../dist/node/index.js',
-      ),
-    ).href
-    // dynamic import should be resolved relative to the original file but
-    // that was never the case so here we're doing the same to resolve it from current config file.
+    Object.assign(globalThis, { __vite_config_import_helper__ })
     output.prepend(
-      `import { __vite_config_import_helper__ } from ${JSON.stringify(vitePath)};` +
-        `const __vite_config_import__ = (id) => __vite_config_import_helper__(${JSON.stringify(importer)}, id);`,
+      `const __vite_config_import__ = (id) => globalThis.__vite_config_import_helper__(${JSON.stringify(importer)}, id);`,
     )
     text = output.toString()
   }
   return text
 }
 
-export async function __vite_config_import_helper__(
+async function __vite_config_import_helper__(
   importer: string,
   id: string,
 ): Promise<unknown> {
diff --git a/packages/vite/src/node/index.ts b/packages/vite/src/node/index.ts
index 814715f12552e6..3d17f8737379d6 100644
--- a/packages/vite/src/node/index.ts
+++ b/packages/vite/src/node/index.ts
@@ -19,11 +19,6 @@ export { fetchModule } from './ssr/fetchModule'
 export type { FetchModuleOptions } from './ssr/fetchModule'
 export * from './publicUtils'
 
-// hide it from dts
-/** @internal */
-export const __vite_config_import_helper__ = __tmp_vite_config_import_helper__
-import { __vite_config_import_helper__ as __tmp_vite_config_import_helper__ } from './config'
-
 // additional types
 export type {
   AppType,

From e8e092af44c3f08d705b22027726d80f88428784 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Thu, 22 Aug 2024 16:00:00 +0900
Subject: [PATCH 13/15] fix: cache bust

---
 packages/vite/src/node/config.ts                      |  3 +++
 playground/config/__tests__/config.spec.ts            | 11 +++++++++++
 .../config/packages/entry/vite.config.reload.ts       |  1 +
 3 files changed, 15 insertions(+)
 create mode 100644 playground/config/packages/entry/vite.config.reload.ts

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 7e7d4e3eebda86..67d3c02526d591 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1293,6 +1293,9 @@ async function loadConfigFromBundledFile(
   // convert to base64, load it with native Node ESM.
   if (isESM) {
     try {
+      // prepend timestamp for import cache busting
+      bundledCode =
+        `"${Date.now()}-${Math.random().toString(16).slice(2)}";` + bundledCode
       return (
         await import(
           'data:text/javascript;base64,' +
diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index 6d79fba0f5ea0b..f1fbcc48c30b9f 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -87,3 +87,14 @@ it('dynamic import', async () => {
     `[Error: Failed to resolve dynamic import 'no-such-module']`,
   )
 })
+
+it('can reload even when same content', async () => {
+  const load = () =>
+    loadConfigFromFile(
+      { command: 'serve', mode: 'development' },
+      resolve(__dirname, '../packages/entry/vite.config.reload.ts'),
+    )
+  const result1 = await load()
+  const result2 = await load()
+  expect(result1.config).not.toBe(result2.config)
+})
diff --git a/playground/config/packages/entry/vite.config.reload.ts b/playground/config/packages/entry/vite.config.reload.ts
new file mode 100644
index 00000000000000..b1c6ea436a5400
--- /dev/null
+++ b/playground/config/packages/entry/vite.config.reload.ts
@@ -0,0 +1 @@
+export default {}

From bc144dd33f3d1904a34597b15b87f153de9a3c30 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Thu, 22 Aug 2024 16:44:53 +0900
Subject: [PATCH 14/15] test: test config load error

---
 playground/config/__tests__/config.spec.ts    | 24 +++++++++++++++++++
 .../packages/entry/vite.config.error-dep.ts   |  1 +
 .../packages/entry/vite.config.error.ts       |  1 +
 .../packages/entry/vite.config.no-export.ts   |  0
 4 files changed, 26 insertions(+)
 create mode 100644 playground/config/packages/entry/vite.config.error-dep.ts
 create mode 100644 playground/config/packages/entry/vite.config.error.ts
 create mode 100644 playground/config/packages/entry/vite.config.no-export.ts

diff --git a/playground/config/__tests__/config.spec.ts b/playground/config/__tests__/config.spec.ts
index f1fbcc48c30b9f..29c2d233cb8513 100644
--- a/playground/config/__tests__/config.spec.ts
+++ b/playground/config/__tests__/config.spec.ts
@@ -98,3 +98,27 @@ it('can reload even when same content', async () => {
   const result2 = await load()
   expect(result1.config).not.toBe(result2.config)
 })
+
+it('no export error', async () => {
+  await expect(() =>
+    loadConfigFromFile(
+      { command: 'serve', mode: 'development' },
+      resolve(__dirname, '../packages/entry/vite.config.no-export.ts'),
+      undefined,
+      'silent',
+    ),
+  ).rejects.toMatchInlineSnapshot(
+    `[Error: config must export or return an object.]`,
+  )
+})
+
+it('error', async () => {
+  await expect(() =>
+    loadConfigFromFile(
+      { command: 'serve', mode: 'development' },
+      resolve(__dirname, '../packages/entry/vite.config.error.ts'),
+      undefined,
+      'silent',
+    ),
+  ).rejects.toThrow(`error-dep at `)
+})
diff --git a/playground/config/packages/entry/vite.config.error-dep.ts b/playground/config/packages/entry/vite.config.error-dep.ts
new file mode 100644
index 00000000000000..4ac02245580728
--- /dev/null
+++ b/playground/config/packages/entry/vite.config.error-dep.ts
@@ -0,0 +1 @@
+throw new Error('error-dep')
diff --git a/playground/config/packages/entry/vite.config.error.ts b/playground/config/packages/entry/vite.config.error.ts
new file mode 100644
index 00000000000000..999e43671a46d7
--- /dev/null
+++ b/playground/config/packages/entry/vite.config.error.ts
@@ -0,0 +1 @@
+import './vite.config.error-dep'
diff --git a/playground/config/packages/entry/vite.config.no-export.ts b/playground/config/packages/entry/vite.config.no-export.ts
new file mode 100644
index 00000000000000..e69de29bb2d1d6

From 5d5b1730e9772070ca07e104ac586a452063845c Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Thu, 22 Aug 2024 18:22:21 +0900
Subject: [PATCH 15/15] test: add vite.config.error-plugin.ts

---
 .../entry/vite.config.error-plugin.ts         | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 playground/config/packages/entry/vite.config.error-plugin.ts

diff --git a/playground/config/packages/entry/vite.config.error-plugin.ts b/playground/config/packages/entry/vite.config.error-plugin.ts
new file mode 100644
index 00000000000000..f800f7349bfa01
--- /dev/null
+++ b/playground/config/packages/entry/vite.config.error-plugin.ts
@@ -0,0 +1,34 @@
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  plugins: [
+    {
+      name: 'test-plugin-error',
+      transform(code, id, options) {
+        testError()
+      },
+    },
+    {
+      name: 'virtual-entry',
+      resolveId(source, importer, options) {
+        if (source === 'virtual:entry') {
+          return '\0' + source
+        }
+      },
+      load(id, options) {
+        if (id === '\0virtual:entry') {
+          return `export default {}`
+        }
+      },
+    },
+  ],
+  build: {
+    rollupOptions: {
+      input: 'virtual:entry',
+    },
+  },
+})
+
+function testError() {
+  throw new Error('Testing Error')
+}