Cheerio (node.js) returns an error on html read

Question

I am completely new to JS, and got completely stuck at the Node Cheerio. I would really appreciate if anyone could help me.

The code I am working on is here: https://github.com/zafartahirov/bitstarter.

(The code that doesn't work will be called grader.old.js after the fix is found).

When I run

node ./grader.js --file index.html --checks checks.json | less

I receive an error:

TypeError: Cannot call method 'utf8Slice' of null
    at Buffer.toString (buffer.js:416:26)
    at exports.isTag (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/lib/utils.js:15:14)
    at Function.filter (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/node_modules/lodash/dist/lodash.js:3150:15)
    at /home/ubuntu/GitHub/bitstarter/node_modules/cheerio/lib/api/traversing.js:9:26
    at Function.reduce (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/node_modules/lodash/dist/lodash.js:3734:25)
    at exports.find (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/lib/api/traversing.js:8:17)
    at new module.exports (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/lib/cheerio.js:92:18)
    at initialize (/home/ubuntu/GitHub/bitstarter/node_modules/cheerio/lib/static.js:23:12)
    at checkHtmlFile (/home/ubuntu/GitHub/bitstarter/grader.js:59:23)
    at Object.<anonymous> (/home/ubuntu/GitHub/bitstarter/grader.js:76:21)
(END)

Any suggestions?

Answer 1

We are taking the same course, and it took me quite some time to debug it. It seems the cheerio.load() method expects a String as an argument and not a buffer.