Cannot read property 'pre' of undefined

[gphillips-ema]

Prerequisites

• Reproduced the problem in Safe Mode (may not be approriate if your error involves markdown-preview-plus): http://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
• Checked that the issue isn't already filed: https://github.com/travs/markdown-pdf/issues)

Issue description

When trying to convert a markdown file to pdf I get the following error in the console.

TypeError: Cannot read property 'pre' of undefined
    at showdownHighlight (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/showdown-highlight/lib/index.js:32)
    at _parseExtension (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/showdown/dist/showdown.js:2301)
    at Array.forEach (<anonymous>)
    at Object.showdown.helper.forEach (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/showdown/dist/showdown.js:653)
    at _constructor (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/showdown/dist/showdown.js:2266)
    at new showdown.Converter (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/showdown/dist/showdown.js:2238)
    at parseMarkdownToHtml (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/mdpdf/src/index.js:69)
    at /Users/gphillips/.atom/packages/markdown-pdf/node_modules/mdpdf/src/index.js:115
    at tryCatcher (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/util.js:16)
    at Promise._settlePromiseFromHandler (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/promise.js:547)
    at Promise._settlePromise (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/promise.js:604)
    at Promise._settlePromise0 (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/promise.js:649)
    at Promise._settlePromises (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/promise.js:729)
    at Promise._fulfill (/Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/promise.js:673)
    at /Users/gphillips/.atom/packages/markdown-pdf/node_modules/bluebird/js/release/nodeback.js:42
    at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:61)

This is followed by another error.

TypeError: Cannot read property 'name' of undefined
    at Object.<anonymous> (fallback.js? [sm]:20)
    at Generator.next (<anonymous>)
    at step (fallback.js? [sm]:28)
    at fallback.js? [sm]:28
    at new Promise (<anonymous>)
    at Object.convert (fallback.js? [sm]:28)
    at Object.<anonymous> (convert.js? [sm]:57)
    at Generator.throw (<anonymous>)
    at step (/Users/gphillips/.atom/packages/markdown-pdf/lib/actions/convert.js:7)

Steps to reproduce

Create a .md file and enter any text.

Trigger conversion to pdf.

Expected behavior: [What you expect to happen]

Generate a pdf document of the markdown file.

Actual behavior: [What actually happens]

Raises an error with prompt to check console.

Input

Any text.

Versions

Atom : 1.57.0
Electron: 9.4.4
Chrome : 83.0.4103.122
Node : 12.14.1

apm 2.6.2
npm 6.14.13
node 12.14.1 x64
atom 1.57.0
python 3.7.6
git 2.30.1