feat: include duplicate assets in the manifest (#9928)

Author: timacdonald

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

@@ -5,6 +5,7 @@ import { Buffer } from 'node:buffer'
 import * as mrmime from 'mrmime'
 import type {
   NormalizedOutputOptions,
+  OutputAsset,
   OutputOptions,
   PluginContext,
   PreRenderedAsset,
@@ -20,6 +21,11 @@ import { FS_PREFIX } from '../constants'
 
 export const assetUrlRE = /__VITE_ASSET__([a-z\d]{8})__(?:\$_(.*?)__)?/g
 
+export const duplicateAssets = new WeakMap<
+  ResolvedConfig,
+  Map<string, OutputAsset>
+>()
+
 const rawRE = /(\?|&)raw(?:&|$)/
 const urlRE = /(\?|&)url(?:&|$)/
 
@@ -129,6 +135,7 @@ export function assetPlugin(config: ResolvedConfig): Plugin {
     buildStart() {
       assetCache.set(config, new Map())
       emittedHashMap.set(config, new Set())
+      duplicateAssets.set(config, new Map())
     },
 
     resolveId(id) {
@@ -470,15 +477,24 @@ async function fileToBuiltUrl(
       map.set(contentHash, fileName)
     }
     const emittedSet = emittedHashMap.get(config)!
+    const duplicates = duplicateAssets.get(config)!
+    const name = normalizePath(path.relative(config.root, file))
     if (!emittedSet.has(contentHash)) {
-      const name = normalizePath(path.relative(config.root, file))
       pluginContext.emitFile({
         name,
         fileName,
         type: 'asset',
         source: content
       })
       emittedSet.add(contentHash)
+    } else {
+      duplicates.set(name, {
+        name,
+        fileName: map.get(contentHash)!,
+        type: 'asset',
+        source: content,
+        isAsset: true
+      })
     }
 
     url = `__VITE_ASSET__${contentHash}__${postfix ? `$_${postfix}__` : ``}` // TODO_BASE

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

@@ -4,6 +4,7 @@ import type { ResolvedConfig } from '..'
 import type { Plugin } from '../plugin'
 import { normalizePath } from '../utils'
 import { cssEntryFilesCache } from './css'
+import { duplicateAssets } from './asset'
 
 export type Manifest = Record<string, ManifestChunk>
 
@@ -122,6 +123,11 @@ export function manifestPlugin(config: ResolvedConfig): Plugin {
         }
       }
 
+      duplicateAssets.get(config)!.forEach((asset) => {
+        const chunk = createAsset(asset)
+        manifest[asset.name!] = chunk
+      })
+
       outputCount++
       const output = config.build.rollupOptions?.output
       const outputLength = Array.isArray(output) ? output.length : 1