Function downloadAssets

packages/cli/src/capture/assetDownloader.ts:20–187

(
  tokens: DesignTokens,
  outputDir: string,
  catalogedAssets?: CatalogedAsset[],
  faviconLinks?: Array<{ rel: string; href: string }>,
)

}

export async function downloadAssets(
  tokens: DesignTokens,
  outputDir: string,
  catalogedAssets?: CatalogedAsset[],
  faviconLinks?: Array<{ rel: string; href: string }>,
): Promise<DownloadedAsset[]> {
  const assetsDir = join(outputDir, "assets");
  mkdirSync(assetsDir, { recursive: true });

  const assets: DownloadedAsset[] = [];
  const downloadedUrls = new Set<string>();

  mkdirSync(join(outputDir, "assets", "svgs"), { recursive: true });
  const usedSvgNames = new Set<string>();
  for (let i = 0; i < tokens.svgs.length && i < 30; i++) {
    const svg = tokens.svgs[i]!;
    if (!svg.outerHTML || svg.outerHTML.length < 50) continue;
    const slug = svgContentHashSlug(svg.outerHTML, !!svg.isLogo);
    let finalSlug = slug;
    let suffix = 2;
    while (usedSvgNames.has(finalSlug)) {
      finalSlug = `${slug}-${suffix}`;
      suffix++;
    }
    usedSvgNames.add(finalSlug);
    const name = `${finalSlug}.svg`;
    const localPath = `assets/svgs/${name}`;
    try {
      writeFileSync(join(outputDir, localPath), svg.outerHTML, "utf-8");
      assets.push({ url: "", localPath, type: "svg" });
    } catch {
      /* skip */
    }
  }

  // 2. Favicon
  for (const icon of faviconLinks || []) {
    if (!icon.href) continue;
    try {
      const ext = extname(new URL(icon.href).pathname) || ".ico";
      const name = `favicon${ext}`;
      const localPath = `assets/${name}`;
      const buffer = await fetchBuffer(icon.href);
      if (buffer) {
        writeFileSync(join(outputDir, localPath), buffer);
        assets.push({ url: icon.href, localPath, type: "favicon" });
        break;
      }
    } catch {
      /* skip */
    }
  }

  // 3. Images — use the catalog as the single source of truth (highest resolution, deduplicated)
  // If the catalog is empty, asset download produces zero images — this is surfaced as a warning
  // so the capture doesn't silently produce a half-empty dataset.
  const imageUrls: { url: string; isPoster: boolean }[] = [];