How to Create a PDF for Unit Testing

November 6, 2019 ยท 1 minute read

Need a dummy PDF? Here’s a small method that will do all the heavy lifting. Just add to your test and call it. It’s just that simple.

func createPDF() 
    let html = "<b>Hello <i>World!</i></b> <p>Generate PDF file from HTML in Swift</p>"
    let fmt = UIMarkupTextPrintFormatter(markupText: html)

    // 2. Assign print formatter to UIPrintPageRenderer

    let render = UIPrintPageRenderer()
    render.addPrintFormatter(fmt, startingAtPageAt: 0)

    // 3. Assign paperRect and printableRect

    let page = CGRect(x: 0, y: 0, width: 595.2, height: 841.8) // A4, 72 dpi
    let printable = page.insetBy(dx: 0, dy: 0)

    render.setValue(NSValue(cgRect: page), forKey: "paperRect")
    render.setValue(NSValue(cgRect: printable), forKey: "printableRect")

    // 4. Create PDF context and draw

    let pdfData = NSMutableData()
    UIGraphicsBeginPDFContextToData(pdfData, .zero, nil)

    for i in 1...render.numberOfPages {
        let bounds = UIGraphicsGetPDFContextBounds()
        render.drawPage(at: i - 1, in: bounds)


    // 5. Save PDF file

    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]

    pdfData.write(toFile: "\(documentsPath)/file.pdf", atomically: true)

Then I loaded it into a WKWebView from the documents directory with this code:

func loadPDF(filename: String) 
    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
    let url = URL(fileURLWithPath: documentsPath, isDirectory: true).appendingPathComponent(filename).appendingPathExtension("pdf")
    let urlRequest = URLRequest(url: url)