fix: Incomplete domain of Java Instant generation (#228)

jcornaz · Oct 20, 2020 · 6ed57fc · 6ed57fc
1 parent 76e7ad5
commit 6ed57fc
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diff --git a/generator/stdlib/src/jvmMain/kotlin/com/github/jcornaz/kwik/generator/stdlib/DateTime.kt b/generator/stdlib/src/jvmMain/kotlin/com/github/jcornaz/kwik/generator/stdlib/DateTime.kt
@@ -47,7 +47,7 @@ public fun Generator.Companion.instants(
             else 0
 
         val maxNano =
-            if (instant.epochSecond == instant.epochSecond) max.nano
+            if (instant.epochSecond == max.epochSecond) max.nano
             else MAX_NANOSECONDS
 
         instant.with(

diff --git a/...dlib/src/jvmTest/kotlin/com/github/jcornaz/kwik/generator/stdlib/DateTimeGeneratorTest.kt b/...dlib/src/jvmTest/kotlin/com/github/jcornaz/kwik/generator/stdlib/DateTimeGeneratorTest.kt
@@ -160,6 +160,31 @@ class InstantGeneratorTest : AbstractGeneratorTest() {
         val max = min.plusSeconds(50)
         assertTrue(Generator.instants(min = min, max = max).randomSequence(0).take(50).any { it == min })
     }
+
+    @Test
+    fun `generate values within complete nanos range if epochsecond is not min boundary`() {
+        val minNanoBoundary = MAX_NANOSECONDS - 10
+        val min = Instant.ofEpochSecond(100, minNanoBoundary)
+        val max = Instant.ofEpochSecond(102, MAX_NANOSECONDS)
+        assertTrue(Generator.instants(min = min, max = max)
+            .randomSequence(0)
+            .take(50)
+            .filter { it.epochSecond > min.epochSecond }
+            .any { it.nano < minNanoBoundary })
+    }
+
+    @Test
+    fun `generate values within complete nanos range if epochsecond is not max boundary`() {
+        val maxNanoBoundary = 10L
+        val min = Instant.ofEpochSecond(100, 0)
+        val max = Instant.ofEpochSecond(102, maxNanoBoundary)
+        assertTrue(Generator.instants(min = min, max = max)
+            .randomSequence(0)
+            .take(50)
+            .filter { it.epochSecond < max.epochSecond }
+            .any { it.nano > maxNanoBoundary })
+    }
+
 }
 
 class LocalTimeGeneratorTest : AbstractGeneratorTest() {