Return search results for partial matches

[DoumanAsh]

For example take this query: https://crates.io/search?q=irc-channel

It gives you exact match.

But if you attempt to remove last letter then you got nothing at all https://crates.io/search?q=irc-channe

Similar issue with _:
https://crates.io/search?q=lazy_static
https://crates.io/search?q=lazy_st

Would it be possible to improve search?

[carols10cents]

It's certainly possible!

[carols10cents]

I don't think this is only a bug when crates contain - or _, there's a crate named acacia but a search for the partial name acaci does not return any results.

[DoumanAsh]

Oh, i didn't notice this. Then it is not a bug, but enhancement.
Anyway it would be good to have

[nisargthakkar]

@carols10cents I believe this issue is arising as a result of postgres ts_query and ts_vector implementations. According to the code, we do plainto_tsquery on the entered query string. This separates the tokens by &.
The first search is made on the column containing tsvector of all keywords, crate name,description, etc. To search this, the matches (@@) operator is used.

[carols10cents]

@nisargthakkar Can you send a pull request with some test cases that fail before the changes that need to be made and pass after?

[nisargthakkar]

@carols10cents I can come up with some test cases but I'm not sure if they'll cover all scenarios as I don't have a good knowledge or any experience working on PostgreSQL

[carols10cents]

@nisargthakkar Oh, your comment made it sound like you knew what was going on and what the problem was. What did you mean by your comment then?

[nisargthakkar]

@carols10cents I was just going through trying to see what was going on and felt that using a LIKE operator might have fixed it. But later I found that it was using PostgreSQL specifics. So, out of curiosity, I went and read up a bit on what the query builder would churn out given the current code base and what the results might be. Since all the tsquery and tsvector concept is totally new to me, I might not be the right person to to implement a fix for this issue.