node-signpdf/src/helpers/findByteRange.test.js

Simple signing of PDFs in node.

import fs from 'fs';
import PDFDocument from 'pdfkit';
import findByteRange from './findByteRange';
import SignPdfError from '../SignPdfError';
import plainAddPlaceholder from './plainAddPlaceholder';

describe('findByteRange', () => {
    it('expects PDF to be Buffer', () => {
        try {
            findByteRange('non-buffer');
            expect('here').not.toBe('here');
        } catch (e) {
            expect(e instanceof SignPdfError).toBe(true);
            expect(e.type).toBe(SignPdfError.TYPE_INPUT);
        }
    });
    it('expects PDF to have a placeholder', () => {
        try {
            const pdf = new PDFDocument({
                autoFirstPage: true,
                size: 'A4',
                layout: 'portrait',
                bufferPages: true,
            });
            pdf.info.CreationDate = '';

            findByteRange(Buffer.from([pdf]));
            expect('here').not.toBe('here');
        } catch (e) {
            expect(e instanceof SignPdfError).toBe(true);
            expect(e.type).toBe(SignPdfError.TYPE_PARSE);
        }
    });
    it('expects to return correct byteRangeString and byteRange', async () => {
        try {
            let pdfBuffer = fs.readFileSync(`${__dirname}/../../resources/no-annotations.pdf`);
            pdfBuffer = plainAddPlaceholder({
                pdfBuffer,
                reason: 'I have reviewed it.',
                signatureLength: 1612,
            });

            const {byteRangePlaceholder, byteRanges} = findByteRange(pdfBuffer);

            expect(byteRangePlaceholder).toBe('/ByteRange [0 /********** /********** /**********]');
            expect(byteRanges[0][0]).toBe('0');
            expect(byteRanges[0][1]).toBe('/**********');
            expect(byteRanges[0][2]).toBe('/**********');
            expect(byteRanges[0][3]).toBe('/**********');
        } catch (e) {
            expect('here').not.toBe('here');
        }
    });
    it('expects byteRangePlaceholder to be undefined', async () => {
        try {
            const pdfBuffer = fs.readFileSync(`${__dirname}/../../resources/signed.pdf`);
            const {byteRangePlaceholder} = findByteRange(pdfBuffer);

            expect(byteRangePlaceholder).toBe(undefined);
        } catch (e) {
            expect('here').not.toBe('here');
        }
    });
    it('expects byteRangeStrings to be pre-defined', async () => {
        try {
            const pdfBuffer = fs.readFileSync(`${__dirname}/../../resources/signed.pdf`);
            const {byteRangeStrings} = findByteRange(pdfBuffer);
            expect(byteRangeStrings[0]).toBe('/ByteRange [0 153 3379 1275]');
        } catch (e) {
            expect('here').not.toBe('here');
        }
    });
});