42 lines
1.5 KiB
Kotlin
42 lines
1.5 KiB
Kotlin
|
package com.hawhamburg.micr0bu
|
||
|
|
|
||
|
|
import com.hawhamburg.micr0bu.domain.asn1.ItsTime
|
||
|
|
import org.junit.Assert.assertEquals
|
||
|
|
import org.junit.Test
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Pins the arithmetic that moves a transmit timestamp from the phone's wall clock onto GNSS time.
|
||
|
|
*
|
||
|
|
* The cases come from the 2026-09-10 bench session. The sending phone's clock was 1456 s fast
|
||
|
|
* because it had no automatic time source, and every CAM it sent was stamped 24 minutes in the
|
||
|
|
* future. After a manual correction it was 6 s slow. Both have to come out on GNSS time.
|
||
|
|
*/
|
||
|
|
class ItsTimeTest {
|
||
|
|
|
||
|
|
private val gnssNow = 1_789_038_922_000L
|
||
|
|
|
||
|
|
@Test
|
||
|
|
fun `without a GNSS reading the wall-clock time is used unchanged`() {
|
||
|
|
assertEquals(1_000L, ItsTime.onGnssTime(systemMs = 1_000L, gnssNowMs = null, systemNowMs = 5_000L))
|
||
|
|
}
|
||
|
|
|
||
|
|
@Test
|
||
|
|
fun `a phone clock running fast is pulled back onto GNSS time`() {
|
||
|
|
val systemNow = gnssNow + 1_456_000L
|
||
|
|
// A fix the wall clock stamped 0.8 s ago. It must still be 0.8 s old afterwards.
|
||
|
|
val fix = systemNow - 800L
|
||
|
|
assertEquals(gnssNow - 800L, ItsTime.onGnssTime(fix, gnssNow, systemNow))
|
||
|
|
}
|
||
|
|
|
||
|
|
@Test
|
||
|
|
fun `a phone clock running slow is pushed forward onto GNSS time`() {
|
||
|
|
val systemNow = gnssNow - 6_000L
|
||
|
|
assertEquals(gnssNow - 250L, ItsTime.onGnssTime(systemNow - 250L, gnssNow, systemNow))
|
||
|
|
}
|
||
|
|
|
||
|
|
@Test
|
||
|
|
fun `an accurate phone clock is left where it is`() {
|
||
|
|
assertEquals(gnssNow - 40L, ItsTime.onGnssTime(gnssNow - 40L, gnssNow, gnssNow))
|
||
|
|
}
|
||
|
|
}
|