Do not search for a "trailer" word in placeholder-plain once the xref position is known

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## [next]
+
+* [placeholder-plain] Fix ability to add a placeholder to a file that contains the "trailer" keyword in plain text.
+
 ## [3.2.1]
 
 * [signer-p12] Fixed JSDoc on the sign() method.

packages/examples/src/multiple-signatures.js

@@ -0,0 +1,91 @@
+var fs = require('fs');
+var path = require('path');
+var plainAddPlaceholder = require('@signpdf/placeholder-plain').plainAddPlaceholder;
+var signpdf = require('@signpdf/signpdf').default;
+var P12Signer = require('@signpdf/signer-p12').P12Signer;
+
+function buyerSign(pdfBuffer, targetPath) {
+    // Add a placeholder for John Doe - the customer
+    var pdfWithPlaceholder = plainAddPlaceholder({
+        pdfBuffer: pdfBuffer,
+        reason: 'Agrees to buy the truck trailer.',
+        contactInfo: '[email protected]',
+        name: 'John Doe',
+        location: 'Free Text Str., Free World',
+    });
+
+    // John signs the PDF
+    // certificate.p12 is the certificate that is going to be used to sign
+    var certificateBuffer = fs.readFileSync(path.join(__dirname, '/../../../resources/certificate.p12'));
+    var signer = new P12Signer(certificateBuffer);
+    return signpdf
+        .sign(pdfWithPlaceholder, signer)
+        .then(function (signedPdf) {
+            // signedPdf is a Buffer of an electronically signed PDF. Store it.
+            fs.writeFileSync(targetPath, signedPdf);
+
+            return signedPdf;
+        })
+}
+
+function sellerSign(pdfBuffer, targetPath) {
+    // Add a placeholder for John Doe - the customer
+    var pdfWithPlaceholder = plainAddPlaceholder({
+        pdfBuffer: pdfBuffer,
+        reason: 'Agrees to sell a truck trailer to John Doe.',
+        contactInfo: '[email protected]',
+        name: 'Thug Dealer',
+        location: 'Automotive Str., Free World',
+    });
+
+    // The seller signs the PDF
+    // bundle.p12 is the certificate bundle that is going to be used to sign
+    var certificateBuffer = fs.readFileSync(path.join(__dirname, '/../../../resources/bundle.p12'));
+    var signer = new P12Signer(certificateBuffer);
+    return signpdf
+        .sign(pdfWithPlaceholder, signer)
+        .then(function (signedPdf) {
+            // signedPdf is a Buffer of an electronically signed PDF. Store it.
+            fs.writeFileSync(targetPath, signedPdf);
+
+            return signedPdf;
+        })
+}
+
+/**
+ * John Doe is buying a truck trailer from Thug Dealer.
+ * The PDF is signed by both parties in two copies.
+ * The first copy is signed by John Doe and then by Thug Dealer.
+ * The second copy is signed by Thug Dealer and then by John Doe.
+ * 4 PDFs are created in the output folder.
+ */
+function work() {
+    // contributing.pdf is the "contract" they are going to sign.
+    var pdfBuffer = fs.readFileSync(path.join(__dirname, '/../../../resources/contributing.pdf'));
+
+    // A copy of the PDF is signed by the buyer and then by the seller.
+    buyerSign(
+        pdfBuffer,
+        path.join(__dirname, '/../output/multiple-signatures-buyer-seller-1.pdf'
+    ))
+        .then(function (signedByCustomer) {
+            return sellerSign(
+                signedByCustomer,
+                path.join(__dirname, '/../output/multiple-signatures-buyer-seller-2.pdf')
+            );
+        });
+
+    // A copy of the PDF is signed by the seller and then by the buyer.
+    sellerSign(
+        pdfBuffer,
+        path.join(__dirname, '/../output/multiple-signatures-seller-buyer-1.pdf'
+    ))
+        .then(function (signedBySeller) {
+            return buyerSign(
+                signedBySeller,
+                path.join(__dirname, '/../output/multiple-signatures-seller-buyer-2.pdf')
+            );
+        });
+}
+
+work();

packages/placeholder-plain/dist/readRefTable.d.ts

@@ -2,21 +2,21 @@ export function getLastTrailerPosition(pdf: any): number;
 export function getXref(pdf: any, position: any): {
     size: any;
     prev: string;
-    xRefContent: Map<any, any>;
+    xRefContent: Map<number, number>;
 };
-export function getFullXrefTable(pdf: Buffer): GetFullXrefTableReturnType;
+export function getFullXrefTable(pdf: Buffer): FullXrefTable;
 export default readRefTable;
-export type GetFullXrefTableReturnType = Map<any, any>;
+export type FullXrefTable = Map<number, number>;
 export type ReadRefTableReturnType = {
     startingIndex: number;
     maxIndex: number;
-    offsets: GetFullXrefTableReturnType;
+    offsets: FullXrefTable;
 };
 /**
  * @typedef {object} ReadRefTableReturnType
  * @prop {number} startingIndex
  * @prop {number} maxIndex
- * @prop {GetFullXrefTableReturnType} offsets
+ * @prop {FullXrefTable} offsets
  */
 /**
  * @param {Buffer} pdfBuffer

packages/placeholder-plain/dist/readRefTable.js

@@ -62,31 +62,39 @@ const getXref = (pdf, position) => {
 };
 
 /**
- * @typedef {Map<*, *>} GetFullXrefTableReturnType
+ * @typedef {Map<number, number>} FullXrefTable
  */
 
 /**
  * @param {Buffer} pdf
- * @returns {GetFullXrefTableReturnType}
+ * @param {number} xRefPosition
+ * @returns {FullXrefTable}
  */
 exports.getXref = getXref;
-const getFullXrefTable = pdf => {
-  const lastTrailerPosition = getLastTrailerPosition(pdf);
-  const lastXrefTable = getXref(pdf, lastTrailerPosition);
+const getFullXref = (pdf, xRefPosition) => {
+  const lastXrefTable = getXref(pdf, xRefPosition);
   if (lastXrefTable.prev === undefined) {
     return lastXrefTable.xRefContent;
   }
-  const pdfWithoutLastTrailer = pdf.slice(0, lastTrailerPosition);
-  const partOfXrefTable = getFullXrefTable(pdfWithoutLastTrailer);
+  const partOfXrefTable = getFullXref(pdf, lastXrefTable.prev);
   const mergedXrefTable = new Map([...partOfXrefTable, ...lastXrefTable.xRefContent]);
   return mergedXrefTable;
 };
 
+/**
+ * @param {Buffer} pdf
+ * @returns {FullXrefTable}
+ */
+const getFullXrefTable = pdf => {
+  const lastTrailerPosition = getLastTrailerPosition(pdf);
+  return getFullXref(pdf, lastTrailerPosition);
+};
+
 /**
  * @typedef {object} ReadRefTableReturnType
  * @prop {number} startingIndex
  * @prop {number} maxIndex
- * @prop {GetFullXrefTableReturnType} offsets
+ * @prop {FullXrefTable} offsets
  */
 
 /**

packages/placeholder-plain/dist/xrefToRefMap.d.ts

@@ -1,3 +1,7 @@
 export default xrefToRefMap;
-declare function xrefToRefMap(xrefString: any): Map<any, any>;
+/**
+ * @param {string} xrefString
+ * @returns {Map<number, number>}
+ */
+declare function xrefToRefMap(xrefString: string): Map<number, number>;
 //# sourceMappingURL=xrefToRefMap.d.ts.map

packages/placeholder-plain/dist/xrefToRefMap.js

@@ -5,6 +5,10 @@ Object.defineProperty(exports, "__esModule", {
 });
 exports.default = void 0;
 var _utils = require("@signpdf/utils");
+/**
+ * @param {string} xrefString
+ * @returns {Map<number, number>}
+ */
 const xrefToRefMap = xrefString => {
   const lines = xrefString.split('\n').filter(l => l !== '');
   let index = 0;

packages/placeholder-plain/src/__snapshots__/readRefTable.test.js.snap

@@ -242,3 +242,39 @@ Object {
   "startingIndex": 0,
 }
 `;
+
+exports[`readRefTable Expects to merge correctly the refTable of resources 8`] = `
+Object {
+  "maxIndex": 27,
+  "offsets": Map {
+    1 => 15,
+    2 => 89780,
+    3 => 265,
+    4 => 302,
+    5 => 27161,
+    6 => 55428,
+    7 => 72070,
+    8 => 378,
+    9 => 592,
+    10 => 764,
+    11 => 4338,
+    12 => 89711,
+    13 => 4443,
+    14 => 26241,
+    15 => 26484,
+    16 => 26817,
+    17 => 27302,
+    18 => 54210,
+    19 => 54444,
+    20 => 55060,
+    21 => 55560,
+    22 => 71288,
+    23 => 71522,
+    24 => 71742,
+    25 => 72781,
+    26 => 89525,
+    27 => 89643,
+  },
+  "startingIndex": 0,
+}
+`;

packages/placeholder-plain/src/readRefTable.js

@@ -82,22 +82,22 @@ export const getXref = (pdf, position) => {
 };
 
 /**
- * @typedef {Map<*, *>} GetFullXrefTableReturnType
+ * @typedef {Map<number, number>} FullXrefTable
  */
 
 /**
  * @param {Buffer} pdf
- * @returns {GetFullXrefTableReturnType}
+ * @param {number} xRefPosition
+ * @returns {FullXrefTable}
  */
-export const getFullXrefTable = (pdf) => {
-    const lastTrailerPosition = getLastTrailerPosition(pdf);
-    const lastXrefTable = getXref(pdf, lastTrailerPosition);
+const getFullXref = (pdf, xRefPosition) => {
+    const lastXrefTable = getXref(pdf, xRefPosition);
 
     if (lastXrefTable.prev === undefined) {
         return lastXrefTable.xRefContent;
     }
-    const pdfWithoutLastTrailer = pdf.slice(0, lastTrailerPosition);
-    const partOfXrefTable = getFullXrefTable(pdfWithoutLastTrailer);
+
+    const partOfXrefTable = getFullXref(pdf, lastXrefTable.prev);
 
     const mergedXrefTable = new Map([
         ...partOfXrefTable,
@@ -107,11 +107,20 @@ export const getFullXrefTable = (pdf) => {
     return mergedXrefTable;
 };
 
+/**
+ * @param {Buffer} pdf
+ * @returns {FullXrefTable}
+ */
+export const getFullXrefTable = (pdf) => {
+    const lastTrailerPosition = getLastTrailerPosition(pdf);
+    return getFullXref(pdf, lastTrailerPosition);
+};
+
 /**
  * @typedef {object} ReadRefTableReturnType
  * @prop {number} startingIndex
  * @prop {number} maxIndex
- * @prop {GetFullXrefTableReturnType} offsets
+ * @prop {FullXrefTable} offsets
  */
 
 /**

packages/placeholder-plain/src/readRefTable.test.js

@@ -75,6 +75,7 @@ describe(readRefTable, () => {
             'incrementally_signed.pdf',
             'signed.pdf',
             'w3dummy.pdf',
+            'issue-209-reason-includes-trailer-word.pdf',
         ].forEach((fileName) => {
             const pdf = readTestResource(fileName);
             const r = readRefTable(pdf);

packages/placeholder-plain/src/xrefToRefMap.js

@@ -1,5 +1,9 @@
 import {SignPdfError} from '@signpdf/utils';
 
+/**
+ * @param {string} xrefString
+ * @returns {Map<number, number>}
+ */
 const xrefToRefMap = (xrefString) => {
     const lines = xrefString.split('\n').filter((l) => l !== '');