Allow custom generators (#847)

* Extract generatedJsonAdapterName to public API for other generators/consumers

* Fix kapt location in tests

* Add IDE-generated dependency-reduced-pom.xml to gitignore

This always bites me

* Add generator property to JsonClass and skip in processor

* Opportunistically fix formatting for generateAdapter doc

* Extract NullSafeJsonAdapter for delegate testing

* Add custom adapter tests

* Allow no-moshi constructors for generated adapters

* Fix rebase issue

* Use something other than nullSafe() for lenient check

This no longer propagates lenient

* Add missing copyrights

* Add top-level class note

* Add note about working against Moshi's generated signature

* Add missing bit to "requirements for"

* Note kotlin requirement relaxed in custom generators

* Style

kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/JsonClassCodegenProcessor.kt

@@ -85,7 +85,7 @@ class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils
   override fun process(annotations: Set<TypeElement>, roundEnv: RoundEnvironment): Boolean {
     for (type in roundEnv.getElementsAnnotatedWith(annotation)) {
       val jsonClass = type.getAnnotation(annotation)
-      if (jsonClass.generateAdapter) {
+      if (jsonClass.generateAdapter && jsonClass.generator.isEmpty()) {
         val generator = adapterGenerator(type) ?: continue
         generator.generateFile(generatedType)
             .writeTo(filer)

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

@@ -26,6 +26,7 @@ import com.squareup.moshi.JsonWriter
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.ToJson
 import com.squareup.moshi.Types
+import com.squareup.moshi.internal.NullSafeJsonAdapter
 import org.assertj.core.api.Assertions.assertThat
 import org.intellij.lang.annotations.Language
 import org.junit.Assert.assertNull
@@ -1155,37 +1156,70 @@ class GeneratedAdaptersTest {
     assertThat(decoded).isEqualTo(HasCollectionOfPrimitives(listOf(4, -5, 6)))
   }
 
-  /**
-   * This is here mostly just to ensure it still compiles. Covers variance, @Json, default values,
-   * nullability, primitive arrays, and some wacky generics.
-   */
-  @JsonClass(generateAdapter = true)
-  data class SmokeTestType(
-    @Json(name = "first_name") val firstName: String,
-    @Json(name = "last_name") val lastName: String,
-    val age: Int,
-    val nationalities: List<String> = emptyList(),
-    val weight: Float,
-    val tattoos: Boolean = false,
-    val race: String?,
-    val hasChildren: Boolean = false,
-    val favoriteFood: String? = null,
-    val favoriteDrink: String? = "Water",
-    val wildcardOut: MutableList<out String> = mutableListOf(),
-    val nullableWildcardOut: MutableList<out String?> = mutableListOf(),
-    val wildcardIn: Array<in String>,
-    val any: List<*>,
-    val anyTwo: List<Any>,
-    val anyOut: MutableList<out Any>,
-    val nullableAnyOut: MutableList<out Any?>,
-    val favoriteThreeNumbers: IntArray,
-    val favoriteArrayValues: Array<String>,
-    val favoriteNullableArrayValues: Array<String?>,
-    val nullableSetListMapArrayNullableIntWithDefault: Set<List<Map<String, Array<IntArray?>>>>? = null,
-    val aliasedName: TypeAliasName = "Woah",
-    val genericAlias: GenericTypeAlias = listOf("Woah")
-  )
+  @JsonClass(generateAdapter = true, generator = "custom")
+  data class CustomGeneratedClass(val foo: String)
+
+  @Test fun customGenerator_withClassPresent() {
+    val moshi = Moshi.Builder().build()
+    val adapter = moshi.adapter(CustomGeneratedClass::class.java)
+    val unwrapped = (adapter as NullSafeJsonAdapter<CustomGeneratedClass>).delegate()
+    assertThat(unwrapped).isInstanceOf(GeneratedAdaptersTest_CustomGeneratedClassJsonAdapter::class.java)
+  }
+
+  @JsonClass(generateAdapter = true, generator = "custom")
+  data class CustomGeneratedClassMissing(val foo: String)
+
+  @Test fun customGenerator_withClassMissing() {
+    val moshi = Moshi.Builder().build()
+    try {
+      moshi.adapter(CustomGeneratedClassMissing::class.java)
+      fail()
+    } catch (e: RuntimeException) {
+      assertThat(e).hasMessageContaining("Failed to find the generated JsonAdapter class")
+    }
+  }
 }
 
+// Has to be outside to avoid Types seeing an owning class
+@JsonClass(generateAdapter = true)
+data class NullableTypeParams<T>(
+    val nullableList: List<String?>,
+    val nullableSet: Set<String?>,
+    val nullableMap: Map<String, String?>,
+    val nullableT: T?,
+    val nonNullT: T
+)
+
+/**
+ * This is here mostly just to ensure it still compiles. Covers variance, @Json, default values,
+ * nullability, primitive arrays, and some wacky generics.
+ */
+@JsonClass(generateAdapter = true)
+data class SmokeTestType(
+  @Json(name = "first_name") val firstName: String,
+  @Json(name = "last_name") val lastName: String,
+  val age: Int,
+  val nationalities: List<String> = emptyList(),
+  val weight: Float,
+  val tattoos: Boolean = false,
+  val race: String?,
+  val hasChildren: Boolean = false,
+  val favoriteFood: String? = null,
+  val favoriteDrink: String? = "Water",
+  val wildcardOut: MutableList<out String> = mutableListOf(),
+  val nullableWildcardOut: MutableList<out String?> = mutableListOf(),
+  val wildcardIn: Array<in String>,
+  val any: List<*>,
+  val anyTwo: List<Any>,
+  val anyOut: MutableList<out Any>,
+  val nullableAnyOut: MutableList<out Any?>,
+  val favoriteThreeNumbers: IntArray,
+  val favoriteArrayValues: Array<String>,
+  val favoriteNullableArrayValues: Array<String?>,
+  val nullableSetListMapArrayNullableIntWithDefault: Set<List<Map<String, Array<IntArray?>>>>? = null,
+  val aliasedName: TypeAliasName = "Woah",
+  val genericAlias: GenericTypeAlias = listOf("Woah")
+)
+
 typealias TypeAliasName = String
 typealias GenericTypeAlias = List<String>

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

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2019 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.moshi.kotlin.codgen
+
+import com.squareup.moshi.JsonAdapter
+import com.squareup.moshi.JsonReader
+import com.squareup.moshi.JsonWriter
+import com.squareup.moshi.kotlin.codgen.GeneratedAdaptersTest.CustomGeneratedClass
+
+// This also tests custom generated types with no moshi constructor
+class GeneratedAdaptersTest_CustomGeneratedClassJsonAdapter : JsonAdapter<CustomGeneratedClass>() {
+  override fun fromJson(reader: JsonReader): CustomGeneratedClass? {
+    TODO()
+  }
+
+  override fun toJson(writer: JsonWriter, value: CustomGeneratedClass?) {
+    TODO()
+  }
+}