Option2-무결성: assets.json SHA-256 무결성 계산 및 referencedAt 추적 TDD/구현

lib/exporter/assets.integrity.sha256.test.ts

@@ -0,0 +1,31 @@
+import { describe, it, expect } from 'vitest'
+import { AssetManager } from '@/lib/assets/assetManager'
+import { buildAssetsMetadata, type AssetMetaItem } from '@/lib/exporter/assets.meta'
+import crypto from 'node:crypto'
+
+function u8pattern(n: number): Uint8Array {
+  const arr = new Uint8Array(n)
+  for (let i = 0; i < n; i++) arr[i] = (i * 131 + 7) & 0xff
+  return arr
+}
+
+function sha256B64(bytes: Uint8Array): string {
+  const h = crypto.createHash('sha256')
+  h.update(Buffer.from(bytes))
+  return h.digest('base64')
+}
+
+describe('assets.json integrity = real SHA-256(base64)', () => {
+  it('integrity equals sha256-<base64(sha256(bytes))>', async () => {
+    const am = new AssetManager({ maxBytes: 1024 * 1024, allowedExts: ['png'] })
+    const bytes = u8pattern(64)
+    await am.add({ name: 'hero.png', type: 'image/png', bytes })
+    const out = buildAssetsMetadata(am)
+    const json = new TextDecoder().decode(out)
+    const obj = JSON.parse(json) as { assets: AssetMetaItem[] }
+    expect(obj.assets.length).toBe(1)
+    const a = obj.assets[0]
+    const expected = 'sha256-' + sha256B64(bytes)
+    expect(a.integrity).toBe(expected)
+  })
+})