feat: add pdf-merge-safe tool (closes #233)

pdf-merge-safe/package-lock.json

@@ -0,0 +1,54 @@
+{
+  "name": "pdf-merge-safe",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "pdf-lib": "^1.17.1"
+      }
+    },
+    "node_modules/@pdf-lib/standard-fonts": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@pdf-lib/standard-fonts/-/standard-fonts-1.0.0.tgz",
+      "integrity": "sha512-hU30BK9IUN/su0Mn9VdlVKsWBS6GyhVfqjwl1FjZN4TxP6cCw0jP2w7V3Hf5uX7M0AZJ16vey9yE0ny7Sa59ZA==",
+      "license": "MIT",
+      "dependencies": {
+        "pako": "^1.0.6"
+      }
+    },
+    "node_modules/@pdf-lib/upng": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@pdf-lib/upng/-/upng-1.0.1.tgz",
+      "integrity": "sha512-dQK2FUMQtowVP00mtIksrlZhdFXQZPC+taih1q4CvPZ5vqdxR/LKBaFg0oAfzd1GlHZXXSPdQfzQnt+ViGvEIQ==",
+      "license": "MIT",
+      "dependencies": {
+        "pako": "^1.0.10"
+      }
+    },
+    "node_modules/pako": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
+      "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw==",
+      "license": "(MIT AND Zlib)"
+    },
+    "node_modules/pdf-lib": {
+      "version": "1.17.1",
+      "resolved": "https://registry.npmjs.org/pdf-lib/-/pdf-lib-1.17.1.tgz",
+      "integrity": "sha512-V/mpyJAoTsN4cnP31vc0wfNA1+p20evqqnap0KLoRUN0Yk/p3wN52DOEsL4oBFcLdb76hlpKPtzJIgo67j/XLw==",
+      "license": "MIT",
+      "dependencies": {
+        "@pdf-lib/standard-fonts": "^1.0.0",
+        "@pdf-lib/upng": "^1.0.1",
+        "pako": "^1.0.11",
+        "tslib": "^1.11.1"
+      }
+    },
+    "node_modules/tslib": {
+      "version": "1.14.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.14.1.tgz",
+      "integrity": "sha512-Xni35NKzjgMrwevysHTCArtLDpPvye8zV/0E4EyYn43P7/7qvQwPh9BGkHewbMulVntbigmcT7rdX3BNo9wRJg==",
+      "license": "0BSD"
+    }
+  }
+}

pdf-merge-safe/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "pdf-lib": "^1.17.1"
+  }
+}

pdf-merge-safe/pdf-merge-safe/package-lock.json

@@ -0,0 +1,58 @@
+{
+  "name": "pdf-merge-safe",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "pdf-merge-safe",
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "pdf-lib": "^1.17.1"
+      }
+    },
+    "node_modules/@pdf-lib/standard-fonts": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@pdf-lib/standard-fonts/-/standard-fonts-1.0.0.tgz",
+      "integrity": "sha512-hU30BK9IUN/su0Mn9VdlVKsWBS6GyhVfqjwl1FjZN4TxP6cCw0jP2w7V3Hf5uX7M0AZJ16vey9yE0ny7Sa59ZA==",
+      "license": "MIT",
+      "dependencies": {
+        "pako": "^1.0.6"
+      }
+    },
+    "node_modules/@pdf-lib/upng": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@pdf-lib/upng/-/upng-1.0.1.tgz",
+      "integrity": "sha512-dQK2FUMQtowVP00mtIksrlZhdFXQZPC+taih1q4CvPZ5vqdxR/LKBaFg0oAfzd1GlHZXXSPdQfzQnt+ViGvEIQ==",
+      "license": "MIT",
+      "dependencies": {
+        "pako": "^1.0.10"
+      }
+    },
+    "node_modules/pako": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
+      "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw==",
+      "license": "(MIT AND Zlib)"
+    },
+    "node_modules/pdf-lib": {
+      "version": "1.17.1",
+      "resolved": "https://registry.npmjs.org/pdf-lib/-/pdf-lib-1.17.1.tgz",
+      "integrity": "sha512-V/mpyJAoTsN4cnP31vc0wfNA1+p20evqqnap0KLoRUN0Yk/p3wN52DOEsL4oBFcLdb76hlpKPtzJIgo67j/XLw==",
+      "license": "MIT",
+      "dependencies": {
+        "@pdf-lib/standard-fonts": "^1.0.0",
+        "@pdf-lib/upng": "^1.0.1",
+        "pako": "^1.0.11",
+        "tslib": "^1.11.1"
+      }
+    },
+    "node_modules/tslib": {
+      "version": "1.14.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.14.1.tgz",
+      "integrity": "sha512-Xni35NKzjgMrwevysHTCArtLDpPvye8zV/0E4EyYn43P7/7qvQwPh9BGkHewbMulVntbigmcT7rdX3BNo9wRJg==",
+      "license": "0BSD"
+    }
+  }
+}

pdf-merge-safe/pdf-merge-safe/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "pdf-merge-safe",
+  "version": "1.0.0",
+  "description": "Merge PDFs with safe handling of encrypted/signed inputs (pdf-lib).",
+  "type": "commonjs",
+  "scripts": {
+    "scan": "node src/scan.js",
+    "merge": "node src/index.js",
+    "merge:yes": "node src/index.js --yes",
+    "make:normal": "node scripts/make-normal.js",
+    "make:encrypted": "node scripts/make-encrypted.js"
+  },
+  "dependencies": {
+    "pdf-lib": "^1.17.1"
+  }
+}

pdf-merge-safe/pdf-merge-safe/scripts/make-normal.js

@@ -0,0 +1,20 @@
+const fs = require("fs");
+const path = require("path");
+const { PDFDocument, StandardFonts, rgb } = require("pdf-lib");
+
+async function make(text, outfile) {
+  const pdf = await PDFDocument.create();
+  const page = pdf.addPage([420, 300]);
+  const font = await pdf.embedFont(StandardFonts.Helvetica);
+  page.drawText(text, { x: 40, y: 150, size: 18, font, color: rgb(0,0,0) });
+  const bytes = await pdf.save();
+  fs.writeFileSync(outfile, bytes);
+  console.log("✅ Created", outfile);
+}
+
+(async () => {
+  const dir = "examples";
+  fs.mkdirSync(dir, { recursive: true });
+  await make("Hello from normal1", path.join(dir, "normal1.pdf"));
+  await make("Hello from normal2", path.join(dir, "normal2.pdf"));
+})();

pdf-merge-safe/pdf-merge-safe/src/index.js

@@ -0,0 +1,94 @@
+const fs = require("fs");
+const path = require("path");
+const { PDFDocument } = require("pdf-lib");
+const { askYesNo } = require("./prompt");
+
+// helpers
+const isPdf = (p) => p.toLowerCase().endsWith(".pdf");
+const exists = (p) => fs.existsSync(p);
+const read = (p) => fs.readFileSync(p);
+
+function listPdfs(target) {
+  if (!exists(target)) return [];
+  const stat = fs.lstatSync(target);
+  if (stat.isDirectory()) {
+    return fs.readdirSync(target)
+      .filter((f) => isPdf(f))
+      .map((f) => path.join(target, f));
+  }
+  return isPdf(target) ? [target] : [];
+}
+
+async function safeLoad(buffer, filename, autoYes) {
+  try {
+    return await PDFDocument.load(buffer); // normal, non-encrypted
+  } catch (err) {
+    const msg = String(err.message).toLowerCase();
+    if (!msg.includes("encrypted")) throw err;
+
+    console.warn(`\n🔐 Detected encrypted/signed file: ${filename}`);
+    console.warn(`⚠️  If you continue, encryption/signature will be REMOVED in merged output.`);
+
+    if (!autoYes) {
+      const ok = await askYesNo("Continue by stripping protection?");
+      if (!ok) return null; // skip
+    }
+    return await PDFDocument.load(buffer, { ignoreEncryption: true });
+  }
+}
+
+async function merge(files, outPath, autoYes) {
+  const merged = await PDFDocument.create();
+  let total = 0;
+
+  for (const file of files) {
+    const buf = read(file);
+    const name = path.basename(file);
+
+    // heuristic signature marker
+    const hasSig = buf.includes("/Sig");
+
+    const doc = await safeLoad(buf, name, autoYes);
+    if (!doc) { console.log(`⏭️  Skipped: ${name}`); continue; }
+
+    if (hasSig) {
+      console.warn(`⚠️  ${name} appears signed. Merging will invalidate the signature.`);
+    }
+
+    const pages = await merged.copyPages(doc, doc.getPageIndices());
+    pages.forEach((p) => merged.addPage(p));
+    total += pages.length;
+    console.log(`➕  Added ${pages.length} page(s) from ${name}`);
+  }
+
+  if (total === 0) { console.log("❌ No pages added. Nothing to save."); return; }
+
+  fs.mkdirSync(path.dirname(outPath), { recursive: true });
+  const bytes = await merged.save();
+  fs.writeFileSync(outPath, bytes);
+  console.log(`\n✅ Saved: ${outPath}  (total pages: ${total})`);
+}
+
+// -------- CLI --------
+// Usage:
+// node src/index.js [--yes|-y] <output.pdf> <fileOrFolder1> [fileOrFolder2 ...]
+(async () => {
+  const args = process.argv.slice(2);
+  const autoYes = args.includes("--yes") || args.includes("-y");
+  const a = args.filter((x) => x !== "--yes" && x !== "-y");
+
+  if (a.length < 2) {
+    console.log("Usage: node src/index.js [--yes|-y] <output.pdf> <fileOrFolder1> [fileOrFolder2 ...]");
+    process.exit(1);
+  }
+
+  const out = a[0];
+  const inputs = a.slice(1);
+
+  let files = [];
+  inputs.forEach((p) => { files = files.concat(listPdfs(p)); });
+
+  if (files.length === 0) { console.log("❌ No PDFs found in given paths."); process.exit(1); }
+
+  await merge(files, out, autoYes);
+})();

pdf-merge-safe/pdf-merge-safe/src/prompt.js

@@ -0,0 +1,13 @@
+const readline = require("readline");
+
+function askYesNo(question) {
+  return new Promise((resolve) => {
+    const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
+    rl.question(`${question} (y/n): `, (ans) => {
+      rl.close();
+      resolve(String(ans).trim().toLowerCase().startsWith("y"));
+    });
+  });
+}
+
+module.exports = { askYesNo };

pdf-merge-safe/pdf-merge-safe/src/scan.js

@@ -0,0 +1,33 @@
+const fs = require("fs");
+const path = require("path");
+const { PDFDocument } = require("pdf-lib");
+
+function gather(p) {
+  if (!fs.existsSync(p)) return [];
+  const stat = fs.lstatSync(p);
+  if (stat.isDirectory()) {
+    return fs.readdirSync(p)
+      .filter((f) => f.toLowerCase().endsWith(".pdf"))
+      .map((f) => path.join(p, f));
+  }
+  return p.toLowerCase().endsWith(".pdf") ? [p] : [];
+}
+
+(async () => {
+  const target = process.argv[2] || "examples";
+  const files = gather(target);
+  if (files.length === 0) { console.log("No PDFs found in", target); process.exit(0); }
+
+  console.log(`🔍 Scanning ${files.length} file(s) in: ${target}\n`);
+  for (const f of files) {
+    const buf = fs.readFileSync(f);
+    const name = path.basename(f);
+
+    let encrypted = false;
+    try { await PDFDocument.load(buf); }
+    catch (e) { encrypted = String(e.message).toLowerCase().includes("encrypted"); }
+
+    const signed = buf.includes("/Sig");
+    console.log(`• ${name}\n   - Encrypted: ${encrypted}\n   - Signed: ${signed}\n`);
+  }
+})();