1 files changed, 74 insertions, 0 deletions
diff --git a/formats/json-tests/commonTest/src/kotlinx/serialization/json/JsonChunkedStringDecoderTest.kt b/formats/json-tests/commonTest/src/kotlinx/serialization/json/JsonChunkedStringDecoderTest.kt
new file mode 100644
index 00000000..fca258fb
--- /dev/null
+++ b/formats/json-tests/commonTest/src/kotlinx/serialization/json/JsonChunkedStringDecoderTest.kt
@@ -0,0 +1,74 @@
+package kotlinx.serialization.json
+
+import kotlinx.serialization.*
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.test.assertFailsWithMessage
+import kotlin.test.*
+
+
+@Serializable(with = LargeStringSerializer::class)
+data class LargeStringData(val largeString: String)
+
+@Serializable
+data class ClassWithLargeStringDataField(val largeStringField: LargeStringData)
+
+
+object LargeStringSerializer : KSerializer<LargeStringData> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("LargeStringContent", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): LargeStringData {
+        require(decoder is ChunkedDecoder) { "Only chunked decoder supported" }
+
+        val outStringBuilder = StringBuilder()
+
+        decoder.decodeStringChunked { chunk ->
+            outStringBuilder.append(chunk)
+        }
+        return LargeStringData(outStringBuilder.toString())
+    }
+
+    override fun serialize(encoder: Encoder, value: LargeStringData) {
+        encoder.encodeString(value.largeString)
+    }
+}
+
+open class JsonChunkedStringDecoderTest : JsonTestBase() {
+
+    @Test
+    fun decodePlainLenientString() {
+        val longString = "abcd".repeat(8192) // Make string more than 16k
+        val sourceObject = ClassWithLargeStringDataField(LargeStringData(longString))
+        val serializedObject = "{\"largeStringField\": $longString }"
+        val jsonWithLenientMode = Json { isLenient = true }
+        testDecodeInAllModes(jsonWithLenientMode, serializedObject, sourceObject)
+    }
+
+    @Test
+    fun decodePlainString() {
+        val longStringWithEscape = "${"abcd".repeat(4096)}\"${"abcd".repeat(4096)}" // Make string more than 16k
+        val sourceObject = ClassWithLargeStringDataField(LargeStringData(longStringWithEscape))
+        val serializedObject = Json.encodeToString(sourceObject)
+        testDecodeInAllModes(Json, serializedObject, sourceObject)
+    }
+
+    private fun testDecodeInAllModes(
+        seralizer: Json, serializedObject: String, sourceObject: ClassWithLargeStringDataField
+    ) {
+        /* Filter out Java Streams mode in common tests. Java streams tested separately in java tests */
+        JsonTestingMode.values().filterNot { it == JsonTestingMode.JAVA_STREAMS }.forEach { mode ->
+            if (mode == JsonTestingMode.TREE) {
+                assertFailsWithMessage<IllegalArgumentException>(
+                    "Only chunked decoder supported", "Shouldn't decode JSON in TREE mode"
+                ) {
+                    seralizer.decodeFromString<ClassWithLargeStringDataField>(serializedObject, mode)
+                }
+            } else {
+                val deserializedObject =
+                    seralizer.decodeFromString<ClassWithLargeStringDataField>(serializedObject, mode)
+                assertEquals(sourceObject.largeStringField, deserializedObject.largeStringField)
+            }
+        }
+    }
+}