ERR_INVALID_URL type errors on links that contain the tel protocol.

[skorasaurus]

Hi,

I apologize, I'm not quite sure if this is applicable to your library or to normalize-url.

I was running another package - (glyphhanger),. I was able to narrow it down and reproduce the error solely using spider-pig.

The issue is that spiderpig (or normalize-url) treats links with the tel protocol as http:// instead of ignoring the url; resulting in an error which I included at the bottom of this issue.

The test-case html file is available at: https://gist.github.com/skorasaurus/8107812d6e34ce3cbd0d5f1bfd318a80

To reproduce:

1. install spiderpig (I did by npm install -g @zachleat/spider-pig)
2. take the test-case html file, uploaded to a server
3. run DEBUG=SpiderPig spiderpig the/path/to/test-case.html
4. receive error in console (shown at the bottom)

As far as I understand, the tel protocol has the + sign as optional at the beginning of the resource; I am able to reproduce the error regardless if the + is included.

According to the RFC standard, these are valid telephone links and they work for me in other circumstances.

The full error that I received is below:

DEBUG=SpiderPig spiderpig http://localhost:8000/test-case.html
  SpiderPig Found origin: 'http://localhost:8000' +0ms
  SpiderPig Found link hrefs: [ 'local-url.html', 'mailto:email@null.com', 'tel:+1-202-762-1401', 'tel:1-202-762-1401' ] +19ms
  SpiderPig Cleaned href: 'http://localhost:8000/local-url.html' (origin: 'http://localhost:8000/test-case.html') +7ms
  SpiderPig Cleaned href: 'http://null.com' (origin: 'http://localhost:8000/test-case.html') +2ms
(node:32311) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_URL]: Invalid URL: http:tel:+1-202-762-1401
    at onParseError (internal/url.js:257:9)
    at new URL (internal/url.js:333:5)
    at normalizeUrl (/home/skoraw/.nvm/versions/node/v12.20.0/lib/node_modules/@zachleat/spider-pig/node_modules/normalize-url/index.js:98:17)
    at SpiderPig.cleanupHref (/home/skoraw/.nvm/versions/node/v12.20.0/lib/node_modules/@zachleat/spider-pig/SpiderPig.js:22:10)
    at SpiderPig.fetchLocalUrls (/home/skoraw/.nvm/versions/node/v12.20.0/lib/node_modules/@zachleat/spider-pig/SpiderPig.js:118:16)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async /home/skoraw/.nvm/versions/node/v12.20.0/lib/node_modules/@zachleat/spider-pig/cmd.js:22:13
(node:32311) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:32311) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.