Minimal Astro 7.2 incrementalBuild image-import cache repro

astro-incremental-build-repro.sh

mkdir -p src/pages src/assets

cat > package.json <<'EOF'
{
  "private": true,
  "type": "module",
  "scripts": { "repro": "node repro.mjs" },
  "dependencies": { "astro": "7.2.0" }
}
EOF

cat > astro.config.mjs <<'EOF'
import { defineConfig } from 'astro/config'

export default defineConfig({
  cacheDir: './.cache',
  experimental: { incrementalBuild: true },
})
EOF

cat > 'src/pages/[slug].astro' <<'EOF'
---
import red from '../assets/red.png'
import blue from '../assets/blue.png'

export function getStaticPaths() {
  return [{ params: { slug: 'post' }, cacheKey: 'unchanged' }]
}
---

<p>{red.src}</p>
<p>{blue.src}</p>
EOF

printf 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEX/AAAZ4gk3AAAACklEQVQI12NgAAAAAgAB4iG8MwAAAABJRU5ErkJggg==' | base64 -d > src/assets/red.png
printf 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAP+KeNJXAAAACklEQVQI12NgAAAAAgAB4iG8MwAAAABJRU5ErkJggg==' | base64 -d > src/assets/blue.png

cat > repro.mjs <<'EOF'
import { spawnSync } from 'node:child_process'
import { createHash } from 'node:crypto'
import { readFileSync, readdirSync, rmSync } from 'node:fs'
import { relative, resolve } from 'node:path'

const route = 'src/pages/[slug].astro'
rmSync('dist', { recursive: true, force: true })
rmSync('.cache', { recursive: true, force: true })
let previous = build()

for (let buildNumber = 1; buildNumber <= 50; buildNumber++) {
  rmSync('dist', { recursive: true, force: true })
  const current = build()
  const before = previous.manifest
  const after = current.manifest

  if (
    before.configHash === after.configHash &&
    before.lockfileHash === after.lockfileHash &&
    JSON.stringify(before.routes[route].paths) === JSON.stringify(after.routes[route].paths) &&
    before.routes[route].dependencyHash !== after.routes[route].dependencyHash &&
    JSON.stringify(previous.files) === JSON.stringify(current.files) &&
    !current.output.includes('(restored)')
  ) {
    console.log(`Reproduced on build ${buildNumber}`)
    console.log(`${before.routes[route].dependencyHash} -> ${after.routes[route].dependencyHash}`)
    console.log('Config, lockfile, cache key, and dist hashes are unchanged; route was not restored.')
    process.exit(0)
  }
  previous = current
}

throw new Error('Not reproduced in 50 builds; run pnpm repro again')

function build() {
  const result = spawnSync('pnpm', ['exec', 'astro', 'build'], { encoding: 'utf8' })
  if (result.status !== 0) throw new Error(result.stdout + result.stderr)
  return {
    manifest: JSON.parse(readFileSync('.cache/incremental-build.json')),
    files: hashes('dist'),
    output: result.stdout + result.stderr,
  }
}

function hashes(directory) {
  const result = {}
  for (const entry of readdirSync(directory, { recursive: true, withFileTypes: true })) {
    if (!entry.isFile()) continue
    const file = resolve(entry.parentPath, entry.name)
    result[relative(directory, file)] = createHash('sha256').update(readFileSync(file)).digest('hex')
  }
  return Object.fromEntries(Object.entries(result).sort())
}
EOF

pnpm install
pnpm repro