Support multiple transient properties in KotlinJsonAdapter.

kotlin/reflect/src/main/java/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapter.kt

@@ -17,7 +17,6 @@ package com.squareup.moshi.kotlin.reflect
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonAdapter
-import com.squareup.moshi.JsonClass
 import com.squareup.moshi.JsonDataException
 import com.squareup.moshi.JsonReader
 import com.squareup.moshi.JsonWriter
@@ -55,34 +54,35 @@ private val ABSENT_VALUE = Any()
  * constructor, and then by setting any additional properties that exist, if any.
  */
 internal class KotlinJsonAdapter<T>(
-    val constructor: KFunction<T>,
-    val bindings: List<Binding<T, Any?>?>,
-    val options: JsonReader.Options) : JsonAdapter<T>() {
+  val constructor: KFunction<T>,
+  val allBindings: List<Binding<T, Any?>?>,
+  val nonTransientBindings: List<Binding<T, Any?>>,
+  val options: JsonReader.Options) : JsonAdapter<T>() {
 
   override fun fromJson(reader: JsonReader): T {
     val constructorSize = constructor.parameters.size
 
     // Read each value into its slot in the array.
-    val values = Array<Any?>(bindings.size) { ABSENT_VALUE }
+    val values = Array<Any?>(allBindings.size) { ABSENT_VALUE }
     reader.beginObject()
     while (reader.hasNext()) {
       val index = reader.selectName(options)
-      val binding = if (index != -1) bindings[index] else null
-
-      if (binding == null) {
+      if (index == -1) {
         reader.skipName()
         reader.skipValue()
         continue
       }
+      val binding = nonTransientBindings[index]
 
-      if (values[index] !== ABSENT_VALUE) {
+      val propertyIndex = binding.propertyIndex
+      if (values[propertyIndex] !== ABSENT_VALUE) {
         throw JsonDataException(
-            "Multiple values for '${constructor.parameters[index].name}' at ${reader.path}")
+            "Multiple values for '${binding.property.name}' at ${reader.path}")
       }
 
-      values[index] = binding.adapter.fromJson(reader)
+      values[propertyIndex] = binding.adapter.fromJson(reader)
 
-      if (values[index] == null && !binding.property.returnType.isMarkedNullable) {
+      if (values[propertyIndex] == null && !binding.property.returnType.isMarkedNullable) {
         throw JsonDataException(
             "Non-null value '${binding.property.name}' was null at ${reader.path}")
       }
@@ -104,8 +104,8 @@ internal class KotlinJsonAdapter<T>(
     val result = constructor.callBy(IndexedParameterMap(constructor.parameters, values))
 
     // Set remaining properties.
-    for (i in constructorSize until bindings.size) {
-      val binding = bindings[i]!!
+    for (i in constructorSize until allBindings.size) {
+      val binding = allBindings[i]!!
       val value = values[i]
       binding.set(result, value)
     }
@@ -117,7 +117,7 @@ internal class KotlinJsonAdapter<T>(
     if (value == null) throw NullPointerException("value == null")
 
     writer.beginObject()
-    for (binding in bindings) {
+    for (binding in allBindings) {
       if (binding == null) continue // Skip constructor parameters that aren't properties.
 
       writer.name(binding.name)
@@ -129,10 +129,11 @@ internal class KotlinJsonAdapter<T>(
   override fun toString() = "KotlinJsonAdapter(${constructor.returnType})"
 
   data class Binding<K, P>(
-      val name: String,
-      val adapter: JsonAdapter<P>,
-      val property: KProperty1<K, P>,
-      val parameter: KParameter?) {
+    val name: String,
+    val adapter: JsonAdapter<P>,
+    val property: KProperty1<K, P>,
+    val parameter: KParameter?,
+    val propertyIndex: Int) {
     fun get(value: K) = property.get(value)
 
     fun set(result: K, value: P) {
@@ -232,7 +233,7 @@ class KotlinJsonAdapterFactory : JsonAdapter.Factory {
       if (parameter != null) {
         allAnnotations += parameter.annotations
         if (jsonAnnotation == null) {
-          jsonAnnotation = parameter.findAnnotation<Json>()
+          jsonAnnotation = parameter.findAnnotation()
         }
       }
 
@@ -242,7 +243,7 @@ class KotlinJsonAdapterFactory : JsonAdapter.Factory {
           resolvedPropertyType, Util.jsonAnnotations(allAnnotations.toTypedArray()), property.name)
 
       bindingsByName[property.name] = KotlinJsonAdapter.Binding(name, adapter,
-          property as KProperty1<Any, Any?>, parameter)
+          property as KProperty1<Any, Any?>, parameter, parameter?.index ?: -1)
     }
 
     val bindings = ArrayList<KotlinJsonAdapter.Binding<Any, Any?>?>()
@@ -250,14 +251,18 @@ class KotlinJsonAdapterFactory : JsonAdapter.Factory {
     for (parameter in constructor.parameters) {
       val binding = bindingsByName.remove(parameter.name)
       if (binding == null && !parameter.isOptional) {
-        throw IllegalArgumentException("No property for required constructor ${parameter}")
+        throw IllegalArgumentException("No property for required constructor $parameter")
       }
       bindings += binding
     }
 
-    bindings += bindingsByName.values
+    var index = bindings.size
+    for (bindingByName in bindingsByName) {
+      bindings += bindingByName.value.copy(propertyIndex = index++)
+    }
 
-    val options = JsonReader.Options.of(*bindings.map { it?.name ?: "\u0000" }.toTypedArray())
-    return KotlinJsonAdapter(constructor, bindings, options).nullSafe()
+    val nonTransientBindings = bindings.filterNotNull()
+    val options = JsonReader.Options.of(*nonTransientBindings.map { it.name }.toTypedArray())
+    return KotlinJsonAdapter(constructor, bindings, nonTransientBindings, options).nullSafe()
   }
 }

kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/codgen/GeneratedAdaptersTest.kt

@@ -557,6 +557,22 @@ class GeneratedAdaptersTest {
   @JsonClass(generateAdapter = true)
   class TransientConstructorParameter(@Transient var a: Int = -1, var b: Int = -1)
 
+  @Test fun multipleTransientConstructorParameters() {
+    val moshi = Moshi.Builder().build()
+    val jsonAdapter = moshi.adapter(MultipleTransientConstructorParameters::class.java)
+
+    val encoded = MultipleTransientConstructorParameters(3, 5, 7)
+    assertThat(jsonAdapter.toJson(encoded)).isEqualTo("""{"b":5}""")
+
+    val decoded = jsonAdapter.fromJson("""{"a":4,"b":6}""")!!
+    assertThat(decoded.a).isEqualTo(-1)
+    assertThat(decoded.b).isEqualTo(6)
+    assertThat(decoded.c).isEqualTo(-1)
+  }
+
+  @JsonClass(generateAdapter = true)
+  class MultipleTransientConstructorParameters(@Transient var a: Int = -1, var b: Int = -1, @Transient var c: Int = -1)
+
   @Test fun transientProperty() {
     val moshi = Moshi.Builder().build()
     val jsonAdapter = moshi.adapter(TransientProperty::class.java)

kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt

@@ -349,6 +349,21 @@ class KotlinJsonAdapterTest {
 
   class TransientConstructorParameter(@Transient var a: Int = -1, var b: Int = -1)
 
+  @Test fun multipleTransientConstructorParameters() {
+    val moshi = Moshi.Builder().add(KotlinJsonAdapterFactory()).build()
+    val jsonAdapter = moshi.adapter(MultipleTransientConstructorParameters::class.java)
+
+    val encoded = MultipleTransientConstructorParameters(3, 5, 7)
+    assertThat(jsonAdapter.toJson(encoded)).isEqualTo("""{"b":5}""")
+
+    val decoded = jsonAdapter.fromJson("""{"a":4,"b":6}""")!!
+    assertThat(decoded.a).isEqualTo(-1)
+    assertThat(decoded.b).isEqualTo(6)
+    assertThat(decoded.c).isEqualTo(-1)
+  }
+
+  class MultipleTransientConstructorParameters(@Transient var a: Int = -1, var b: Int = -1, @Transient var c: Int = -1)
+
   @Test fun requiredTransientConstructorParameterFails() {
     val moshi = Moshi.Builder().add(KotlinJsonAdapterFactory()).build()
     try {