title: SerializationException: can't locate argument-less serializer
body: <p>I'm creating a Kotlin Multiplatform library; actually I got 3 modules ( <em>common</em>, <em>jvm</em> and <em>js</em> ),</p>
  
  <p>In the classpath I got: <code>classpath "org.jetbrains.kotlin:kotlin-serialization:${versions.kotlin}"</code></p>
  
  <p>And in my modules I got:</p>
  
  <ul>
  <li>common: <code>"org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:${versions.kotlinSerialization}"</code></li>
  <li>jdk: <code>"org.jetbrains.kotlinx:kotlinx-serialization-runtime:${versions.kotlinSerialization}"</code></li>
  <li>js: <code>"org.jetbrains.kotlinx:kotlinx-serialization-runtime-js:${versions.kotlinSerialization}"</code></li>
  </ul>
  
  <p>and <code>apply plugin: 'kotlinx-serialization'</code> ofc.</p>
  
  <p>&#x200B;</p>
  
  <p>But when I run this simple test:</p>
  
  <pre><code>@Serializable
  data class ASimpleClass( val a: Int )
  </code></pre>
  
  <p>.</p>
  
  <pre><code>@Test  
  fun testingMultiplatformCode_canSerialize() {
      JSON.stringify( ASimpleClass( 1 ) )
  }
  </code></pre>
  
  <p>I got this error:</p>
  
  <pre><code>kotlinx.serialization.SerializationException: Can't locate argument-less serializer for class studio.forface.ktmdb.ASimpleClass. For generic classes, such as lists, please provide serializer explicitly.
  
      at kotlinx.serialization.PlatformUtilsKt.serializer(PlatformUtils.kt:28)
      at studio.forface.ktmdb.ProjectTests.testingMultiplatformCode_canSerialize(ProjectTests.kt:33)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
      at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
      at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
      at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
      at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
      at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
      at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
      at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
      at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
      at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
      at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
      at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
      at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
      at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
      at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
      at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
      at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
      at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
  </code></pre>
  
  <p>I have same result annotating the property "a" ( <code>@SerialName</code> ), which shouldn't require an annotation anyway.</p>
  
  <p>Am I missing something? :/ thanks</p>