Canvas element causes incorrect rendering when used more than once or in a loop - PDFMake

I'm trying to generate multiple PDFs server side using PDFMake. Each PDF has a certain section that's constant across all PDFs to be generated, general. That general section is then separated by a line and then the information specific to that document is loaded in beneath it.

This works great on the first PDF. On the second, however, the layout breaks. How can I fix this?

First PDF:

Second PDF:

 "use strict";
  const fs = require("fs");
  const PdfPrinter = require("pdfmake");

  const fonts = {
    Helvetica: {
      normal: "Helvetica",
      bold: "Helvetica-Bold",
      italics: "Helvetica-Oblique",
      bolditalics: "Helvetica-BoldOblique",
    },
  };

  const printer = new PdfPrinter(fonts);

  const general = [{ text: "This is general text" }];

  const first = [{ text: "This is the text for the first pdf" }];

  const second = [{ text: "This is the text for the second pdf" }];

  const line = [{canvas: [{ type: 'line', x1: 0, y1: 5, x2: 595-2*40, y2: 5, lineWidth: 2 }],margin: [ 0, 10, 0, 10 ]},];


  let docDefinition = {
    pageSize: "letter",
    defaultStyle: {
      font: "Helvetica"
    }
  };

  docDefinition.content = [general,line,first];
  let pdfDoc = printer.createPdfKitDocument(docDefinition);
  pdfDoc.pipe(fs.createWriteStream('one.pdf'));
  pdfDoc.end();


  docDefinition.content = [general,line,second];
  pdfDoc = printer.createPdfKitDocument(docDefinition);
  pdfDoc.pipe(fs.createWriteStream('two.pdf'));
  pdfDoc.end();

So I asked a question on the GitHub issues page and the response was:

One docDefinition variable can be used only once to generate PDF.

While that may be true I did find an adequate workaround by using a table with just the headerLine. This isn't my idea but I can't remember where I got it from.

function line() {
  //Usually one would use a canvas to draw the line
  //{canvas: [{ type: 'line', x1: 0, y1: 5, x2: 595-2*40, y2: 5, lineWidth: 2 }],margin: [ 0, 10, 0, 0 ]},
  //For some reason, that's not working and the layout just breaks
    return {
      table : {
        headerRows : 1,
        widths: ['100%'],
        body : [
                [''],
                ['']
                ]
        },
        layout : 'headerLineOnly'
    }
} 

Then you use line() anywhere in your docDefinition that you need a line.

"use strict";
  const fs = require("fs");
  const PdfPrinter = require("pdfmake");

  const fonts = {
    Helvetica: {
      normal: "Helvetica",
      bold: "Helvetica-Bold",
      italics: "Helvetica-Oblique",
      bolditalics: "Helvetica-BoldOblique",
    },
  };

  const printer = new PdfPrinter(fonts);

  const general = [{ text: "This is general text" }];

  const first = [{ text: "This is the text for the first pdf" }];

  const second = [{ text: "This is the text for the second pdf" }];



  let docDefinition = {
    pageSize: "letter",
    defaultStyle: {
      font: "Helvetica"
    }
  };

  docDefinition.content = [general,line(),first];
  let pdfDoc = printer.createPdfKitDocument(docDefinition);
  pdfDoc.pipe(fs.createWriteStream('one.pdf'));
  pdfDoc.end();