Add JsonString recipe to examples (#1230)

* Start recipes module with JsonString recipe

* Make recipes a kotlin project

* Move JsonString sample to examples

* Add license

* Include all java modules

* Add kotlin options

* Spotless

* Remove jvmtarget

I was today years old when I found out 1.7 isn't a valid target

* Make gradle happy

* Add codegen

* Spotless

build.gradle.kts

@@ -112,7 +112,7 @@ subprojects {
     }
   }
 
-  pluginManager.withPlugin("java-library") {
+  pluginManager.withPlugin("java") {
     configure<JavaPluginExtension> {
       sourceCompatibility = JavaVersion.VERSION_1_7
       targetCompatibility = JavaVersion.VERSION_1_7

examples/build.gradle.kts

@@ -14,11 +14,21 @@
  * limitations under the License.
  */
 
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 plugins {
-  `java-library`
+  kotlin("jvm")
+  kotlin("kapt")
+}
+
+tasks.withType<KotlinCompile>().configureEach {
+  kotlinOptions {
+    freeCompilerArgs = listOf("-progressive")
+  }
 }
 
 dependencies {
+  kapt(project(":kotlin:codegen"))
   compileOnly(Dependencies.jsr305)
   implementation(project(":moshi"))
   implementation(project(":adapters"))

examples/src/main/java/com/squareup/moshi/recipes/JsonString.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2020 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
+ *
+ *    https://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.recipes
+
+import com.squareup.moshi.JsonAdapter
+import com.squareup.moshi.JsonClass
+import com.squareup.moshi.JsonQualifier
+import com.squareup.moshi.JsonReader
+import com.squareup.moshi.JsonWriter
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.Moshi.Builder
+import com.squareup.moshi.Types
+import okio.BufferedSource
+import java.lang.reflect.Type
+import kotlin.annotation.AnnotationRetention.RUNTIME
+
+@JsonClass(generateAdapter = true)
+data class ExampleClass(
+  val type: Int,
+  @JsonString val rawJson: String
+)
+
+@Retention(RUNTIME)
+@JsonQualifier
+annotation class JsonString
+
+class JsonStringJsonAdapterFactory : JsonAdapter.Factory {
+  override fun create(type: Type, annotations: Set<Annotation>, moshi: Moshi): JsonAdapter<*>? {
+    if (type != String::class.java) return null
+    Types.nextAnnotations(annotations, JsonString::class.java) ?: return null
+    return JsonStringJsonAdapter().nullSafe()
+  }
+
+  private class JsonStringJsonAdapter : JsonAdapter<String>() {
+    override fun fromJson(reader: JsonReader): String =
+      reader.nextSource().use(BufferedSource::readUtf8)
+
+    override fun toJson(writer: JsonWriter, value: String?) {
+      writer.valueSink().use { sink -> sink.writeUtf8(checkNotNull(value)) }
+    }
+  }
+}
+
+fun main() {
+  //language=JSON
+  val json = "{\"type\":1,\"rawJson\":{\"a\":2,\"b\":3,\"c\":[1,2,3]}}"
+
+  val moshi = Builder()
+    .add(JsonStringJsonAdapterFactory())
+    .build()
+
+  val example: ExampleClass = moshi.adapter(ExampleClass::class.java).fromJson(json)!!
+
+  check(example.type == 1)
+
+  //language=JSON
+  check(example.rawJson == "{\"a\":2,\"b\":3,\"c\":[1,2,3]}")
+}

kotlin/codegen/build.gradle.kts

@@ -35,6 +35,12 @@ tasks.withType<KotlinCompile>().configureEach {
   }
 }
 
+// To make Gradle happy
+java {
+  sourceCompatibility = JavaVersion.VERSION_1_8
+  targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 val shade: Configuration = configurations.maybeCreate("compileShaded")
 configurations.getByName("compileOnly").extendsFrom(shade)
 dependencies {