Simple.kt

// Sample JSON
// { "bar": "hello world" }

// The Foo class
@JsonClass(generateAdapter = true)
data class Foo(
    val bar: String
)

// Generated by Moshi Kotlin Code Gen
class FooJsonAdapter(moshi: Moshi) : JsonAdapter<Foo>() {
    private val options: JsonReader.Options = JsonReader.Options.of("bar")

    private val stringAdapter: JsonAdapter<String> = moshi.adapter(String::class.java).nonNull()

    override fun toString(): String = "GeneratedJsonAdapter(Foo)"

    override fun fromJson(reader: JsonReader): Foo {
        var bar: String? = null
        reader.beginObject()
        while (reader.hasNext()) {
            when (reader.selectName(options)) {
                0 -> bar = stringAdapter.fromJson(reader) ?: throw JsonDataException("Non-null value 'bar' was null at ${reader.path}")
                -1 -> {
                    // Unknown name, skip it.
                    reader.skipName()
                    reader.skipValue()
                }
            }
        }
        reader.endObject()
        var result = Foo(
                bar = bar ?: throw JsonDataException("Required property 'bar' missing at ${reader.path}"))
        return result
    }

    override fun toJson(writer: JsonWriter, value: Foo?) {
        if (value == null) {
            throw NullPointerException("value was null! Wrap in .nullSafe() to write nullable values.")
        }
        writer.beginObject()
        writer.name("bar")
        stringAdapter.toJson(writer, value.bar)
        writer.endObject()
    }
}