fix(build): resolve rollupOptions.input paths

packages/plugin-legacy/index.js

@@ -596,7 +596,7 @@ async function buildPolyfillChunk(
   bundle[polyfillChunk.name] = polyfillChunk
 }
 
-const polyfillId = 'vite/legacy-polyfills'
+const polyfillId = '\0vite/legacy-polyfills'
 
 /**
  * @param {Set<string>} imports

packages/vite/src/node/__tests__/build.spec.ts

@@ -1,5 +1,6 @@
 import { resolveLibFilename } from '../build'
 import { resolve } from 'path'
+import { resolveConfig } from '..'
 
 describe('resolveLibFilename', () => {
   test('custom filename function', () => {
@@ -65,3 +66,72 @@ describe('resolveLibFilename', () => {
     }).toThrow()
   })
 })
+
+describe('resolvePaths', () => {
+  test('resolve build.rollupOptions.input', async () => {
+    const config = await resolveConfig({
+      build: {
+        rollupOptions: {
+          input: 'index.html'
+        }
+      }
+    }, 'build', 'production')
+
+    expect(config.build.rollupOptions.input).toBe(resolve('index.html'))
+  })
+  test('resolve build.rollupOptions.input{}', async () => {
+    const config = await resolveConfig({
+      build: {
+        rollupOptions: {
+          input: {
+            index: 'index.html'
+          }
+        }
+      }
+    }, 'build', 'production')
+
+    expect(config.build.rollupOptions.input['index']).toBe(resolve('index.html'))
+  })
+
+  test('resolve build.rollupOptions.input[]', async () => {
+    const config = await resolveConfig({
+      build: {
+        rollupOptions: {
+          input: ['index.html']
+        }
+      }
+    }, 'build', 'production')
+
+    expect(config.build.rollupOptions.input).toStrictEqual([resolve('index.html')])
+  })
+
+  test('resolve index.html', async () => {
+    const config = await resolveConfig({}, 'build', 'production')
+
+    expect(config.build.rollupOptions.input).toBe(resolve('index.html'))
+  })
+
+  test('resolve build.outdir', async () => {
+    const config = await resolveConfig({ build: { outDir: 'outDir' } }, 'build', 'production')
+
+    expect(config.build.outDir).toBe(resolve('outDir'))
+  })
+
+  test('resolve default build.outdir', async () => {
+    const config = await resolveConfig({}, 'build', 'production')
+
+    expect(config.build.outDir).toBe(resolve('dist'))
+  })
+
+  test('resolve build.lib.entry', async () => {
+    const config = await resolveConfig({ build: { lib: { entry: 'index.html' } } }, 'build', 'production')
+
+    expect(config.build.rollupOptions.input).toBe(resolve('index.html'))
+  })
+
+  test('resolve build.ssr', async () => {
+    const config = await resolveConfig({ build: { ssr: 'ssr.ts' } }, 'build', 'production')
+
+    expect(config.build.rollupOptions.input).toBe(resolve('ssr.ts'))
+  })
+})

packages/vite/src/node/build.ts

@@ -233,7 +233,7 @@ export type ResolvedBuildOptions = Required<
   >
 >
 
-export function resolveBuildOptions(raw?: BuildOptions): ResolvedBuildOptions {
+export function resolveBuildOptions(root: string, raw?: BuildOptions): ResolvedBuildOptions {
   const resolved: ResolvedBuildOptions = {
     target: 'modules',
     polyfillModulePreload: true,
@@ -269,6 +269,40 @@ export function resolveBuildOptions(raw?: BuildOptions): ResolvedBuildOptions {
     }
   }
 
+  const resolve = (p: string) => p.startsWith('\0') ? p : path.resolve(root, p)
+
+  resolved.outDir = resolve(resolved.outDir)
+
+  let input
+
+  if (raw?.rollupOptions?.input) {
+    input = Array.isArray(raw.rollupOptions.input)
+      ? raw.rollupOptions.input.map(input => resolve(input))
+      : typeof raw.rollupOptions.input === 'object'
+      ? Object.assign(
+          // @ts-ignore
+          ...Object.keys(raw.rollupOptions.input).map(key => ({ [key]: resolve(raw.rollupOptions.input[key]) }))
+        )
+      : resolve(raw.rollupOptions.input)
+  } else {
+    input = resolve(
+      raw?.lib
+        ? raw.lib.entry
+        : typeof raw?.ssr === 'string'
+        ? raw.ssr
+        : 'index.html'
+    )
+  }
+
+  if (!!raw?.ssr && typeof input === 'string' && input.endsWith('.html')) {
+    throw new Error(
+      `rollupOptions.input should not be an html file when building for SSR. ` +
+        `Please specify a dedicated SSR entry.`
+    )
+  }
+
+  resolved.rollupOptions.input = input
+
   // handle special build targets
   if (resolved.target === 'modules') {
     // Support browserslist
@@ -362,6 +396,8 @@ async function doBuild(
 ): Promise<RollupOutput | RollupOutput[] | RollupWatcher> {
   const config = await resolveConfig(inlineConfig, 'build', 'production')
   const options = config.build
+  const input = options.rollupOptions.input
+  const outDir = options.outDir
   const ssr = !!options.ssr
   const libOptions = options.lib
 
@@ -373,22 +409,6 @@ async function doBuild(
     )
   )
 
-  const resolve = (p: string) => path.resolve(config.root, p)
-  const input = libOptions
-    ? resolve(libOptions.entry)
-    : typeof options.ssr === 'string'
-    ? resolve(options.ssr)
-    : options.rollupOptions?.input || resolve('index.html')
-
-  if (ssr && typeof input === 'string' && input.endsWith('.html')) {
-    throw new Error(
-      `rollupOptions.input should not be an html file when building for SSR. ` +
-        `Please specify a dedicated SSR entry.`
-    )
-  }
-
-  const outDir = resolve(options.outDir)
-
   // inject ssr arg to plugin load/transform hooks
   const plugins = (
     ssr ? config.plugins.map((p) => injectSsrFlagToHooks(p)) : config.plugins
@@ -421,7 +441,6 @@ async function doBuild(
 
   const rollup = require('rollup') as typeof Rollup
   const rollupOptions: RollupOptions = {
-    input,
     context: 'globalThis',
     preserveEntrySignatures: ssr
       ? 'allow-extension'

packages/vite/src/node/config.ts

@@ -364,7 +364,7 @@ export async function resolveConfig(
 
   // resolve public base url
   const BASE_URL = resolveBaseUrl(config.base, command === 'build', logger)
-  const resolvedBuildOptions = resolveBuildOptions(config.build)
+  const resolvedBuildOptions = resolveBuildOptions(resolvedRoot, config.build)
 
   // resolve cache directory
   const pkgPath = lookupFile(