add test for issue #120

[mojoaxel]

• add test for Do we have support for secured PDFs on the browser version? #120

[mojoaxel]

The tests are failing with this error message:

 FAIL  test/issues.test.js
  ● Console

    console.warn
      Trying to parse invalid object: {"line":34,"column":6,"offset":19800})

      at PDFParser.Object.<anonymous>.PDFParser.tryToParseInvalidIndirectObject (node_modules/pdf-lib/src/core/parser/PDFParser.ts:185:13)
      at PDFParser.<anonymous> (node_modules/pdf-lib/src/core/parser/PDFParser.ts:224:14)
      at step (node_modules/tslib/tslib.js:141:27)
      at Object.throw (node_modules/tslib/tslib.js:122:57)
      at rejected (node_modules/tslib/tslib.js:113:69)

    console.warn
      Invalid object ref: 22 0 R

      at PDFParser.Object.<anonymous>.PDFParser.tryToParseInvalidIndirectObject (node_modules/pdf-lib/src/core/parser/PDFParser.ts:189:13)
      at PDFParser.<anonymous> (node_modules/pdf-lib/src/core/parser/PDFParser.ts:224:14)
      at step (node_modules/tslib/tslib.js:141:27)
      at Object.throw (node_modules/tslib/tslib.js:122:57)
      at rejected (node_modules/tslib/tslib.js:113:69)

  ● issues › merge a encrypted pdf (#120)

    Expected instance of PDFDict, but got instance of undefined

      57 |     const src = await this._getInputAsBuffer(input)
      58 |     const srcDoc = await PDFDocument.load(src, this.loadOptions)
    > 59 |     const pageIndices = srcDoc.getPageIndices()
         |                                ^
      60 |
      61 |     const copiedPages = await this.doc.copyPages(srcDoc, pageIndices)
      62 |     copiedPages.forEach((page) => {

      at new UnexpectedObjectTypeError (node_modules/pdf-lib/src/core/errors.ts:31:5)
      at PDFContext.Object.<anonymous>.PDFContext.lookup (node_modules/pdf-lib/src/core/PDFContext.ts:166:11)
      at PDFCatalog.Object.<anonymous>.PDFDict.lookup (node_modules/pdf-lib/src/core/objects/PDFDict.ts:143:38)
      at PDFCatalog.Object.<anonymous>.PDFCatalog.Pages (node_modules/pdf-lib/src/core/structures/PDFCatalog.ts:24:17)
      at Cache.PDFDocument.computePages [as populate] (node_modules/pdf-lib/src/api/PDFDocument.ts:1366:18)
      at Cache.Object.<anonymous>.Cache.access (node_modules/pdf-lib/src/utils/Cache.ts:17:40)
      at PDFDocument.Object.<anonymous>.PDFDocument.getPages (node_modules/pdf-lib/src/api/PDFDocument.ts:557:27)
      at PDFDocument.Object.<anonymous>.PDFDocument.getPageCount (node_modules/pdf-lib/src/api/PDFDocument.ts:540:61)
      at PDFDocument.Object.<anonymous>.PDFDocument.getPageIndices (node_modules/pdf-lib/src/api/PDFDocument.ts:591:26)
      at PDFMerger.getPageIndices [as _addEntireDocument] (index.js:59:32)
      at PDFMerger.add (index.js:21:7)
      at Object.<anonymous> (test/issues.test.js:42:5)

It looks to me like this is an issue in the pdf-lib we can not do anything about:
Hopding/pdf-lib#1274

[mojoaxel]

There is an issue with the provided pdf document from #120
Looks like this is a pdf-lib problem, we can not solve and that has nothing to do with #120 / #88