Fix custom nav links

[frapan]

Description of changes

There are 3 bugs that get fixed with this pull request:

1. There was an error in the unit test about the accepted languages which made "npm test" fail (see file /test/unit/lib/middleware/language.js)
2. In Keystone v0.3 it was possibile to add an object (or an array of objects) to the nav to make external links. In v4.0 it was only possibile to add an array of objects, forcing you to wrap the object inside an array. With this pull request you can add single objects again.
3. If you add an object (inside an array) with an external link to the nav, v4.0 shows the link but it is erroneously wrapped inside a Link component and therefore the router cannot handle it. This behaviour has been changed so that external links are represented simply by "a" tags, not by Link components.

Related issues

The following issues are related to this pull request:

• Adding links to custom pages in admin UI #3676: this issue is about bug number 3 and could be closed
• Add nav-links for custom pages #1645: this issue is about bugs number 2 and 3 and could be closed with a note: afaik it's not possibile to use an external link starting with /keystone/ beacuse it would be intercepted by the router.

Testing

• Please confirm npm run test-all ran successfully.

[frapan]

How do I know what's wrong with deploy/netlify? The deploy preview failed but I don't think it's because of my changes.
If I click on the Details link, I get a 404 (I signed up to netlify with github account).
Can anyone help me?

[frapan]

I've just realized that the netlify deploy went wrong beacuse of the commit about the nav section as simple objects.
Should I assume that this behaviour is not wanted anymore?
Should I remove that commit?
Or the netlify deploy should be fixed to let nav sections be simple objects?

[frapan]

@JedWatson can you please answer me? Or could you please invite me to the slack channel in order to discuss about theese questions?

[frapan]

@mxstbr can you help me with this pull request? I have no access to the netlify logs (see my comments above) and I don't know what the problem is.
I tried to reset the initNav.js as it was before my pull request but it keeps on giving me the same netlify failure.
How can I work it out? If you invite me to the Keystone slack, do you think I could find an answer?
Thanks.

[thekevinbrown]

Hey @frapan, sorry for the delay in getting back to you. The only thing I don't understand in your PR is the change to this file. Could you let me know what this is doing for us? I'd be happy to merge the other changes, just want to make sure I understand what's happening here.

[frapan]

Thank you @blargity for your reply and I'm sorry as well for being late.
I had an error during tests because of that line, and I couldn't go on with the tests.
In fact, the syntax of acceptLanguage expects the weights of the languages to be written with ";q=", not simply ";".
See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Language as a reference.

[Noviny]

@frapan Thankyou for some more patience!

I was wondering if you would mind documenting this feature, likely on this page. I like my hidden features in video games, but less so in my node modules. 😛

[frapan]

@Noviny I agree with you. I've just added the documentation to the page you suggested.