Hi all, I'm trying to refactor some code, and I fe...

# announcements

[bodiam]

Hi all, I'm trying to refactor some code, and I feel like I'm almost there, but I can't find the last missing bit. I have the following code:

MemberTbl.select {
    MemberTbl.member_id eq "200"
}.first().also {
   assertThat(it[MemberTbl.id]).isEqualTo("200")
}

But, I'd like to refactor it to something like: MemberTbl.findByMemberId("200") with the help of an extension function, since this code is duplicated quite a lot.

What I have so far is this:

private fun MemberTbl.findByMemberId(s: String, row: ResultRow.() -> Unit) = this.select { member_id eq s }.first().also { row (it)  }

So that my end result will look like this:

MemberTbl.findByMemberId("200") {
     assertThat(it[MemberTbl.id]).isEqualTo("200")
}

But that won't, since the it in the assertEquals is no longer the closure passed in. How can I fix this?

[wasyl]

There’s no assertEquals in the second snippet. I’m having trouble understanding the issue 🤔

[bodiam]

@wasyl is this more clear?

[wasyl]

I think so, yes. So would it work if you had (ResultRow) -> Unit instead of ResultRow.() -> Unit?

[wasyl]

Because with the second one there’s no it anymore, instead the value being passed is an implicit receiver, so you can access it with this. Perhaps the assertion could look like this.get(MemberTbl.id).isEqualTo("200" with current version

[bodiam]

You're a life saver! 🙂

[bodiam]

private fun MemberTbl.findByMemberId(s: String, row:( ResultRow) -> Unit) = this.select { member_id eq s }.first().also(row)

[bodiam]

works

[bodiam]

Thanks for helping out, appreciate it a lot!! 🌮

[wasyl]

I think these are called function literals with receiver. Basically with (X) -> Unit you get { it == X }, while X.() -> Unit means { this == X} (and there’s no it at all). So you still could use the second one if you wanted to, just with this instead of it

[bodiam]

That's a great explanation, thanks for that! Getting the braces and brackets in the right spot was the hard part, but with your explanation it makes sense, thanks!