Introduce TestClock.plusAssign(Duration) and hide implementation details

TestClock.plusAssign(Duration) is for advancing TestClock time. Hide reading value, do not allow to provide initial reading, fix clock unit to nanoseconds at construction time.
2019-08-08 22:40:36 +03:00
parent 4de9361c37
commit f889d25287
5 changed files with 111 additions and 20 deletions
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+@file:UseExperimental(ExperimentalTime::class)
+package test.time
+
+import kotlin.test.*
+import kotlin.time.*
+
+class TestClockTest {
+
+    @Test
+    fun overflows() {
+        for (enormousDuration in listOf(Duration.INFINITE, Double.MAX_VALUE.nanoseconds, Long.MAX_VALUE.nanoseconds * 2)) {
+            assertFailsWith<IllegalStateException>(enormousDuration.toString()) { TestClock() += enormousDuration }
+            assertFailsWith<IllegalStateException>((-enormousDuration).toString()) { TestClock() += -enormousDuration }
+        }
+
+        val moderatePositiveDuration = Long.MAX_VALUE.takeHighestOneBit().nanoseconds
+        val borderlinePositiveDuration = Long.MAX_VALUE.nanoseconds // rounded to 2.0^63, which is slightly more than Long.MAX_VALUE
+        val borderlineNegativeDuration = Long.MIN_VALUE.nanoseconds
+        run {
+            val clock = TestClock()
+            clock += moderatePositiveDuration
+            assertFailsWith<IllegalStateException>("Should overflow positive") { clock += moderatePositiveDuration }
+        }
+        run {
+            val clock = TestClock()
+            clock += borderlinePositiveDuration
+            assertFailsWith<IllegalStateException>("Should overflow positive") { clock += 1.nanoseconds }
+        }
+        run {
+            val clock = TestClock()
+            clock += borderlineNegativeDuration
+            assertFailsWith<IllegalStateException>("Should overflow negative") { clock += -1.nanoseconds }
+        }
+
+        run {
+            val clock = TestClock()
+            clock += moderatePositiveDuration
+            // does not overflow event if duration doesn't fit in long
+            clock += -moderatePositiveDuration + borderlineNegativeDuration
+        }
+    }
+
+    @Test
+    fun nanosecondRounding() {
+        val clock = TestClock()
+        val mark = clock.mark()
+
+        repeat(10_000) {
+            clock += 0.9.nanoseconds
+
+            assertEquals(Duration.ZERO, mark.elapsed())
+        }
+
+        clock += 1.9.nanoseconds
+        assertEquals(1.nanoseconds, mark.elapsed())
+    }
+}