1 files changed, 67 insertions, 0 deletions
diff --git a/formats/json-tests/commonTest/src/kotlinx/serialization/features/SkipDefaults.kt b/formats/json-tests/commonTest/src/kotlinx/serialization/features/SkipDefaults.kt
new file mode 100644
index 00000000..a7fea75f
--- /dev/null
+++ b/formats/json-tests/commonTest/src/kotlinx/serialization/features/SkipDefaults.kt
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2017-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.features
+
+import kotlinx.serialization.*
+import kotlinx.serialization.EncodeDefault.Mode.*
+import kotlinx.serialization.json.*
+import kotlin.test.*
+
+class SkipDefaultsTest {
+    private val jsonDropDefaults = Json { encodeDefaults = false }
+    private val jsonEncodeDefaults = Json { encodeDefaults = true }
+
+    @Serializable
+    data class Data(val bar: String, val foo: Int = 42) {
+        var list: List<Int> = emptyList()
+        val listWithSomething: List<Int> = listOf(1, 2, 3)
+    }
+
+    @Serializable
+    data class DifferentModes(
+        val a: String = "a",
+        @EncodeDefault val b: String = "b",
+        @EncodeDefault(ALWAYS) val c: String = "c",
+        @EncodeDefault(NEVER) val d: String = "d"
+    )
+
+    @Test
+    fun serializeCorrectlyDefaults() {
+        val d = Data("bar")
+        assertEquals(
+            """{"bar":"bar","foo":42,"list":[],"listWithSomething":[1,2,3]}""",
+            jsonEncodeDefaults.encodeToString(Data.serializer(), d)
+        )
+    }
+
+    @Test
+    fun serializeCorrectly() {
+        val d = Data("bar", 100).apply { list = listOf(1, 2, 3) }
+        assertEquals(
+            """{"bar":"bar","foo":100,"list":[1,2,3]}""",
+            jsonDropDefaults.encodeToString(Data.serializer(), d)
+        )
+    }
+
+    @Test
+    fun serializeCorrectlyAndDropBody() {
+        val d = Data("bar", 43)
+        assertEquals("""{"bar":"bar","foo":43}""", jsonDropDefaults.encodeToString(Data.serializer(), d))
+    }
+
+    @Test
+    fun serializeCorrectlyAndDropAll() {
+        val d = Data("bar")
+        assertEquals("""{"bar":"bar"}""", jsonDropDefaults.encodeToString(Data.serializer(), d))
+    }
+
+    @Test
+    fun encodeDefaultsAnnotationWithFlag() {
+        val data = DifferentModes()
+        assertEquals("""{"a":"a","b":"b","c":"c"}""", jsonEncodeDefaults.encodeToString(data))
+        assertEquals("""{"b":"b","c":"c"}""", jsonDropDefaults.encodeToString(data))
+    }
+
+}