Add test cases

from #976

Author: k163377

src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/github/GitHub976.kt

@@ -0,0 +1,31 @@
+package com.fasterxml.jackson.module.kotlin.test.github
+
+import com.fasterxml.jackson.databind.exc.InvalidNullException
+import com.fasterxml.jackson.module.kotlin.KotlinFeature
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import org.junit.jupiter.api.assertThrows
+import kotlin.test.Test
+
+class GitHub976 {
+    data class PrimitiveList(val list: List<Int>)
+
+    @Test
+    fun strictNullChecks() {
+        val om = jacksonObjectMapper {
+            enable(KotlinFeature.StrictNullChecks)
+        }
+        assertThrows<InvalidNullException> {
+            om.readValue("""{"list": [""] }""".toByteArray(), PrimitiveList::class.java)
+        }
+    }
+
+    @Test
+    fun newStrictNullChecksRegression() {
+        val om = jacksonObjectMapper {
+            enable(KotlinFeature.NewStrictNullChecks)
+        }
+        assertThrows<InvalidNullException> {
+            om.readValue("""{"list": [""] }""".toByteArray(), PrimitiveList::class.java)
+        }
+    }
+}