Add the End symbol to start somewhere and end at the end

[Ocyss]

I want to start from a certain page to the end. I initially used regular expressions to replace end with 999999, but I found that this would cause an error. It exceeded the original page, so I initiated this issue.

I thought of an elegant solution. I can add an enforceMaxPage configuration to new PDFMerger() to enable the maximum number of pages to be used when the pages exceed the number of pages. Then I can also use end and start to represent the beginning and end.

// inputFile page = 5
const merger1 = new PDFMerger()
await merger1.add(inputFile, '2-9'); // throw Err

const merger2 = new PDFMerger({enforceMaxPage: true})
await merger2.add(inputFile, '2-9'); // 2,3,4,5

// inputFile page = 5
const merger = new PDFMerger()
await merger.add(inputFile, '2-End'); // 2,3,4,5
await merger.add(inputFile, '2-end'); // 2,3,4,5
await merger.add(inputFile, '3-e'); // 3,4,5
await merger.add(inputFile, 'start-end'); // 1,2,3,4,5
await merger.add(inputFile, 's-2'); // 1,2

[mojoaxel]

@Ocyss Thanks! This is a good idea!