Prevent search for invalid queries

[aenglisc]

There seems to be no good reason to trigger a search if the query is invalid.

Apparently fixes this issue.

[ericmj]

We should use this regex: https://github.com/hexpm/hexpm/blob/master/lib/hexpm/repository/package.ex#L67.

[aenglisc]

Should we though? To me a query that starts with a number (say, 3339) or a capital letter seems fairly legitimate. 🤔

[joladev]

I don't feel that validating the queries is an improvement here. Looking up package names is not an expensive operation, it's easier to just let users search for what they want. And suggestions will still work, even if the query includes characters that are not allowed in Hex package names, eg typing in "pho!nix" will suggest "phoenix".

[aenglisc]

And suggestions will still work, even if the query includes characters that are not allowed in Hex package names, eg typing in "pho!nix" will suggest "phoenix".

That's a good point. The reason why this idea came to me in the first place was that it's not uncommon for people with non-latin keyboards (including myself) to forget to switch, thus, say phoenix would become зрщутшч, ending up in multiple completely wasted search attempts. Perhaps adding some kind of filter would be a better option. Or maybe something even more exciting, such as a mapping mechanism that would transform the aforementioned зрщутшч back into phoenix? Although the latter would seem fairly unrealistic given the amount of languages in the world.