Goldebek/scripts/strip-image-metadata.mjs

import fs from "node:fs";
import path from "node:path";
import sharp from "sharp";

const PUBLIC_IMAGES_DIR = path.resolve(import.meta.dirname, "../public/images");
const SUPPORTED_EXTENSIONS = new Set([".jpg", ".jpeg", ".png", ".webp", ".avif"]);
const METADATA_FIELDS = ["exif", "icc", "iptc", "xmp"];
const CHECK_ONLY = process.argv.includes("--check");

function collectImages(directory) {
  if (!fs.existsSync(directory)) return [];

  const files = [];
  for (const entry of fs.readdirSync(directory, { withFileTypes: true })) {
    const fullPath = path.join(directory, entry.name);
    if (entry.isDirectory()) {
      files.push(...collectImages(fullPath));
      continue;
    }

    if (entry.isFile() && SUPPORTED_EXTENSIONS.has(path.extname(entry.name).toLowerCase())) {
      files.push(fullPath);
    }
  }
  return files;
}

function getEncoder(pipeline, extension) {
  if (extension === ".png") {
    return pipeline.png({ compressionLevel: 9, adaptiveFiltering: true });
  }
  if (extension === ".webp") {
    return pipeline.webp({ quality: 80 });
  }
  if (extension === ".avif") {
    return pipeline.avif({ quality: 50 });
  }
  return pipeline.jpeg({ quality: 85, progressive: true, mozjpeg: true });
}

async function hasMetadata(filePath) {
  const metadata = await sharp(filePath).metadata();
  return METADATA_FIELDS.some((field) => Boolean(metadata[field]));
}

async function stripMetadata(filePath) {
  const extension = path.extname(filePath).toLowerCase();
  const tempPath = `${filePath}.tmp`;
  if (fs.existsSync(tempPath)) {
    fs.rmSync(tempPath);
  }

  const pipeline = sharp(filePath).rotate();
  await getEncoder(pipeline, extension).toFile(tempPath);
  fs.renameSync(tempPath, filePath);
}

const files = collectImages(PUBLIC_IMAGES_DIR);
const filesWithMetadata = [];

for (const file of files) {
  if (await hasMetadata(file)) {
    filesWithMetadata.push(file);
  }
}

if (CHECK_ONLY) {
  for (const file of filesWithMetadata) {
    console.error(`[images:check-metadata] Metadata found: ${file}`);
  }
  if (filesWithMetadata.length > 0) {
    process.exitCode = 1;
  } else {
    console.log(`[images:check-metadata] ${files.length} images checked; no metadata blocks found.`);
  }
} else {
  for (const file of filesWithMetadata) {
    await stripMetadata(file);
  }
  console.log(
    `[images:strip-metadata] ${filesWithMetadata.length} of ${files.length} images rewritten.`,
  );
}