Support packages that emit auxiliary assets

.changeset/calm-assets-build.md

@@ -0,0 +1,5 @@
+---
+'package-build-stats': patch
+---
+
+Support packages that emit auxiliary assets such as WebAssembly files.

src/getDependencySizeTree.ts

@@ -186,6 +186,14 @@ async function bundleSizeTree(
   const makeModule = (
     mod: RspackModule,
   ): { path: string; source: string } | null => {
+    if (
+      mod.moduleType &&
+      !mod.moduleType.startsWith('javascript') &&
+      !mod.moduleType.startsWith('json')
+    ) {
+      return null
+    }
+
     const identifier = mod.identifier || ''
     const resolvedPath = modulePath(identifier)
     const source = normaliseModuleSource(mod)

src/utils/build.utils.ts

@@ -332,16 +332,9 @@ const BuildUtils = {
       throwIfAborted(options.signal)
       const gzip = gzipSync(bundleContents, {}).length
       const matches = asset.name.match(/(.+?)\.bundle\.(.+)$/)
-
-      if (!matches) {
-        throw new UnexpectedBuildError(
-          'Found an asset without the `.bundle` suffix. ' +
-            'A loader customization might be needed to recognize this asset type' +
-            asset.name,
-        )
-      }
-
-      const [, entryName, extension] = matches
+      const parsedAssetName = path.parse(asset.name)
+      const entryName = matches?.[1] || parsedAssetName.name
+      const extension = matches?.[2] || parsedAssetName.ext.slice(1) || 'asset'
 
       return {
         name: entryName,

tests/fast/build.utils.test.ts

@@ -1,4 +1,5 @@
 import { afterEach, describe, expect, test, vi } from 'vitest'
+import fs from 'node:fs'
 import { BuildCancelledError } from '../../src/errors/CustomError'
 
 const mockRspack = vi.fn()
@@ -15,6 +16,8 @@ vi.mock('../../src/config/makeRspackConfig.js', () => ({
 vi.mock('../../src/utils/telemetry.utils.js', () => ({
   default: {
     compilePackage: mockCompilePackage,
+    parseWebpackStats: vi.fn(),
+    assetsGZIPParseTime: vi.fn(),
   },
 }))
 
@@ -213,4 +216,32 @@ describe('BuildUtils.buildPackage', () => {
       missingModules: ['missing-package'],
     })
   })
+
+  test('preserves emitted assets that do not use the bundle filename pattern', async () => {
+    const stats = {
+      compilation: { errors: [] },
+      toJson: () => ({
+        assets: [
+          { name: 'main.bundle.js', size: 100, chunkNames: ['main'] },
+          { name: 'assets/module.wasm', size: 50, chunkNames: [] },
+        ],
+      }),
+    }
+
+    vi.spyOn(BuildUtils, 'createEntryPoint').mockReturnValue('/tmp/index.js')
+    vi.spyOn(BuildUtils, 'compilePackage').mockResolvedValue({
+      error: null,
+      stats: stats as any,
+    })
+    vi.spyOn(fs.promises, 'readFile').mockResolvedValue(
+      Buffer.from('asset contents'),
+    )
+
+    await expect(BuildUtils.buildPackage(buildArgs)).resolves.toMatchObject({
+      assets: [
+        { name: 'main', type: 'js', size: 100 },
+        { name: 'module', type: 'wasm', size: 50 },
+      ],
+    })
+  })
 })

tests/fast/getDependencySizeTree.test.ts

@@ -137,6 +137,32 @@ describe('getDependencySizeTree - accuracy', () => {
     }
   })
 
+  it('does not pass non-JavaScript modules to the JavaScript minifier', async () => {
+    const base = '/project'
+    const javascriptSource = 'export const value = 42'
+    const stats = createStats([
+      {
+        identifier: `${base}/node_modules/wasm-package/index.js`,
+        moduleType: 'javascript/esm',
+        source: javascriptSource,
+      },
+      {
+        identifier: `webassembly/async|${base}/node_modules/wasm-package/module.wasm|evaluation`,
+        moduleType: 'webassembly/async',
+        source: Buffer.from([0x00, 0x01, 0x02, 0x03]),
+      },
+    ])
+
+    const result = await getDependencySizeTree('fixture-pkg', stats)
+
+    expect(result).toEqual([
+      {
+        name: 'wasm-package',
+        approximateSize: await minifiedUtf8Size(javascriptSource),
+      },
+    ])
+  })
+
   it('aggregates nested pnpm, scoped, buffer, and virtual deps into accurate package sizes', async () => {
     const base = '/project'
     const levelOneSource = 'export const levelOne = () => "one"'