Introduce JsonTestingMode.EFFICIENT_BINARY as mode that involves a roundtrip

through the EfficientBinaryFormat.

Author: pdvrieze

formats/json-tests/commonTest/src/kotlinx/serialization/json/JsonErrorMessagesTest.kt

@@ -131,7 +131,7 @@ class JsonErrorMessagesTest : JsonTestBase() {
             // it can be some kind of path `{"foo:bar:baz":"my:resource:locator:{123}"}` or even URI used as a string key/value.
             // So if the closing quote is missing, there's really no way to correctly tell where the key or value is supposed to end.
             // Although we may try to unify these messages for consistency.
-            if (mode in setOf(JsonTestingMode.STREAMING, JsonTestingMode.TREE))
+            if (mode in setOf(JsonTestingMode.STREAMING, JsonTestingMode.TREE, JsonTestingMode.EFFICIENT_BINARY))
                 assertContains(
                     message,
                     "Unexpected JSON token at offset 7: Expected quotation mark '\"', but had ':' instead at path: \$"
@@ -145,7 +145,7 @@ class JsonErrorMessagesTest : JsonTestBase() {
         checkSerializationException({
             default.decodeFromString(serString, input2, mode)
         }, { message ->
-            if (mode in setOf(JsonTestingMode.STREAMING, JsonTestingMode.TREE))
+            if (mode in setOf(JsonTestingMode.STREAMING, JsonTestingMode.TREE, JsonTestingMode.EFFICIENT_BINARY))
                 assertContains(
                     message,
                     "Unexpected JSON token at offset 13: Expected quotation mark '\"', but had '}' instead at path: \$"

formats/json-tests/commonTest/src/kotlinx/serialization/json/JsonTestBase.kt

@@ -26,7 +26,8 @@ enum class JsonTestingMode {
     TREE,
     OKIO_STREAMS,
     JAVA_STREAMS,
-    KXIO_STREAMS;
+    KXIO_STREAMS,
+    EFFICIENT_BINARY;
 
     companion object {
         fun value(i: Int) = values()[i]
@@ -42,6 +43,7 @@ abstract class JsonTestBase {
         return encodeToString(serializer, value, jsonTestingMode)
     }
 
+    @OptIn(ExperimentalStdlibApi::class)
     internal fun <T> Json.encodeToString(
         serializer: SerializationStrategy<T>,
         value: T,
@@ -68,13 +70,26 @@ abstract class JsonTestBase {
                 encodeToSink(serializer, value, buffer)
                 buffer.readString()
             }
+            JsonTestingMode.EFFICIENT_BINARY -> {
+                val ebf = EfficientBinaryFormat()
+                val bytes = runCatching { ebf.encodeToByteArray(serializer, value) }.getOrElse { e->
+                    null//throw e
+                }
+                if (bytes != null && serializer is KSerializer<*>) {
+                    val decoded = ebf.decodeFromByteArray((serializer as KSerializer<T>), bytes)
+                    encodeToString(serializer, decoded)
+                } else {
+                    encodeToString(serializer, value)
+                }
+            }
         }
 
     internal inline fun <reified T : Any> Json.decodeFromString(source: String, jsonTestingMode: JsonTestingMode): T {
         val deserializer = serializersModule.serializer<T>()
         return decodeFromString(deserializer, source, jsonTestingMode)
     }
 
+    @OptIn(ExperimentalStdlibApi::class)
     internal fun <T> Json.decodeFromString(
         deserializer: DeserializationStrategy<T>,
         source: String,
@@ -101,6 +116,20 @@ abstract class JsonTestBase {
                 buffer.writeString(source)
                 decodeFromSource(deserializer, buffer)
             }
+            JsonTestingMode.EFFICIENT_BINARY -> {
+                when (deserializer){
+                    is KSerializer<*> -> {
+                        val s = deserializer as KSerializer<T>
+                        val value = decodeFromString(deserializer, source)
+                        runCatching {
+                            val ebf = EfficientBinaryFormat()
+                            val binaryValue = EfficientBinaryFormat().encodeToByteArray(s, value)
+                            ebf.decodeFromByteArray(s, binaryValue)
+                        }.getOrElse { value }
+                    }
+                    else -> decodeFromString(deserializer, source)
+                }
+            }
         }
 
     protected open fun parametrizedTest(test: (JsonTestingMode) -> Unit) {
@@ -145,7 +174,10 @@ abstract class JsonTestBase {
         @OptIn(ExperimentalStdlibApi::class)
         override fun <T> encodeToString(serializer: SerializationStrategy<T>, value: T): String {
             bytes = runCatching { ebf.encodeToByteArray(serializer, value) }
-                .onFailure { if ("Json format" !in it.message!!) throw it }
+                .onFailure { if ("Json format" !in it.message!!) {
+                    json.encodeToString(serializer, value) // trigger throwing the json exception if the exception is there
+                    throw it
+                } }
                 .getOrNull()
             return json.encodeToString(serializer, value).also {
                 if (bytes != null) jsonStr = it