fix(common): UTC 상대시간 파싱을 보완한다

app/src/test/java/kr/co/vividnext/sodalive/common/RelativeTimeFormatterTest.kt

@@ -0,0 +1,70 @@
+package kr.co.vividnext.sodalive.common
+
+import android.app.Application
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import kr.co.vividnext.sodalive.R
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [28], application = Application::class)
+class RelativeTimeFormatterTest {
+
+    private val context: Context = ApplicationProvider.getApplicationContext()
+
+    @Test
+    fun `epoch millis는 기존처럼 실제 경과 분을 표시한다`() {
+        val twoMinutesAgoMillis = System.currentTimeMillis() - 2 * MINUTE
+
+        val text = formatUtcRelativeTimeText(context, twoMinutesAgoMillis.toString())
+
+        assertEquals(context.getString(R.string.character_comment_time_minutes, 2), text)
+    }
+
+    @Test
+    fun `epoch seconds는 초 단위로 파싱한다`() {
+        val twoHoursAgoSeconds = (System.currentTimeMillis() - 2 * HOUR) / 1000
+
+        val text = formatUtcRelativeTimeText(context, twoHoursAgoSeconds.toString())
+
+        assertEquals(context.getString(R.string.character_comment_time_hours, 2), text)
+    }
+
+    @Test
+    fun `ISO UTC 문자열은 작성 직후 서버 단말 시계 차이를 방금전으로 보정한다`() {
+        val sixMinutesAgoIso = utcIso(System.currentTimeMillis() - 6 * MINUTE)
+
+        val text = formatUtcRelativeTimeText(context, sixMinutesAgoIso)
+
+        assertEquals(context.getString(R.string.character_comment_time_just_now), text)
+    }
+
+    @Test
+    fun `ISO offset 문자열과 6자리 fraction을 UTC 기준으로 파싱한다`() {
+        val value = utcIso(System.currentTimeMillis())
+            .replace(".000Z", ".123456+00:00")
+
+        val text = formatUtcRelativeTimeText(context, value)
+
+        assertEquals(context.getString(R.string.character_comment_time_just_now), text)
+    }
+
+    private fun utcIso(millis: Long): String {
+        return SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US).apply {
+            timeZone = TimeZone.getTimeZone("UTC")
+        }.format(Date(millis))
+    }
+
+    private companion object {
+        const val MINUTE = 60_000L
+        const val HOUR = 60 * MINUTE
+    }
+}