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?

There’s no

assertEquals

in the second snippet. I’m having trouble understanding the issue 🤔

@wasyl is this more clear?

I think so, yes. So would it work if you had

(ResultRow) -> Unit

instead of

ResultRow.() -> Unit

?

You're a life saver! 🙂

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

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!