Support packages that emit auxiliary assets (#95)

* fix: support auxiliary build assets

* Use Rspack naming for WebAssembly assets

Author: pastelsky

.changeset/calm-assets-build.md

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

src/config/makeRspackConfig.ts

@@ -198,6 +198,7 @@ export default function makeRspackConfig({
     },
     output: {
       filename: '[name].bundle.js',
+      webassemblyModuleFilename: '[hash].bundle.wasm',
       path: outputPath,
     },
     externals: ({ request }, callback) =>

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)

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"'

tests/fast/makeRspackConfig.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, test } from 'vitest'
+
+import makeRspackConfig from '../../src/config/makeRspackConfig.js'
+
+describe('makeRspackConfig', () => {
+  test('uses the bundle filename convention for WebAssembly modules', () => {
+    const config = makeRspackConfig({
+      packageName: 'fixture',
+      entry: '/tmp/index.js',
+      externals: {
+        externalPackages: [],
+        externalBuiltIns: [],
+      },
+      outputPath: '/tmp/output',
+    })
+
+    expect(config.output?.webassemblyModuleFilename).toBe('[hash].bundle.wasm')
+  })
+})