How do you test an extension function that is a cl...

# test

[Gilberto Diaz]

How do you test an extension function that is a class member. Lets consider this example

class DateUtils {
  fun LocalDateTime.setTimeZone(targetTimeZone: String): LocalDateTime {
        return ZonedDateTime.of(
            this,
            ZoneId.of(targetTimeZone)
        ).toLocalDateTime()
    }
}

@Test
fun `It should set time zone`() {
  val msgDateStr = "2020-03-07T11:55:00"
  val format = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss")
  al currDate = LocalDateTime.parse(msgDateStr, format)
  assertEquals("2020-03-07T11:55-05:00[America/New_York]", DateUtils.setTimeZone(currDate, "America/NewYork"))
}

DateUtils.setTimeZome(...) // I get a Unresolved reference: setTimeZone

[Daniel]

Is there any reason why the extension function is a member? This is pretty unusual

[Gilberto Diaz]

probably bad design from my part. what would be the right way to create a class and extensions functions from that class

[aandreyev]

with(DateUtils()){
            assertEquals("2020-03-07T11:55-05:00[America/New_York]", currDate.setTimeZone( "America/NewYork"))
        }

[aandreyev]

it compiles, but assert fails

[Gilberto Diaz]

from currDate.setTimeZone(...) // Unresolved reference: setTimeZone

[Gilberto Diaz]

IDEA complains

[Gilberto Diaz]

strange that DateTimeFormatter.ofPattern(…) // Unresolved reference: ofPattern

[aandreyev]

perhaps imports are different..

[aandreyev]

message has been deleted

[Gilberto Diaz]

🤔

[Daniel]

Top level, without any wrapping class.

fun LocalDateTime.setTimeZone(targetTimeZone: String): LocalDateTime {
        return ZonedDateTime.of(
            this,
            ZoneId.of(targetTimeZone)
        ).toLocalDateTime()
    }

In LocalDateTimeExt.kt file for example

[Gilberto Diaz]

I see

[Daniel]

Next is be sure that you have all dependencies in the test source set also. I come from the gradle world and there it is testImplementation ect. No idea how it is handled in maven though

[Gilberto Diaz]

that worked. takin the extension outside the class