Better Error Messaging for Invalid URLs

[SiobhyB]

Expected behavior

If I enter an invalid URL at the login form, I expect to receive an informative, helpful error message that informs me why I'm not able to log into the app.

Actual behavior

The following error appears if I enter an invalid URL at the login form, which isn't that helpful to users:

"Couldn't connect to WordPress site. There is no valid WordPress site at this address. Check the site address (URL) you entered."

Screenshot:

Steps to reproduce the behavior

1. Navigate to the app's login screen and select the "Log in by entering site address" option.
2. Enter some nonsense text, for example "DFOJDOFJF".

Tested on Pixel, alpha-132 of WordPress for Android

This was raised by @jtreanor and some other recent support rotations as a lot of support requests are made up of users who enter an invalid URL. More informative error messaging could have a positive impact on the number of incoming requests.

iOS version of this issue is here: wordpress-mobile/WordPress-iOS#10294

[thehenrybyrd]

Ran into this in #1648733-zen, where the user had entered the URL "Santara Net Review".
It would be great to produce an error that states this isn't a URL, and gives an example of a URL.

[thehenrybyrd]

Another in #1666486-zen - the user entered "La vie d'una Maison"

[thehenrybyrd]

#1667453-zen - the user entered "Datos".
Looks like some folks don't understand they need a "domain.tld" format for this to work. They're entering the name/title of their site, instead.

[thehenrybyrd]

#1693402-zen, entered "mcgospelentertainment".

[thehenrybyrd]

Here's another who entered "Estanislao Mallofre Jane". #1749121-zen

[thehenrybyrd]

Another example here in #1834758-zen

[thehenrybyrd]

Another case in 1899497-zen. They've entered an apparently random sequence of numbers and letters.

[thehenrybyrd]

Another in 1923800-zen. Again, a random-looking sequence of numbers and letters.

[designsimply]

Raising in priority due to the number of user reports referenced.

[thehenrybyrd]

Thanks Sheri!
I ran into another of these today in 1949634-zen.
Folks seem to think they can just type in relevant search terms.
I blame Google 😆

[oguzkocer]

I have made a design request for this and already received some tips. I also requested a copy for it. Once I get the copy, I'll open a PR for it.