Initial fix for geocoder toJson issue

build.gradle

@@ -22,7 +22,7 @@ buildscript {
 
 tasks.withType(JavaCompile) {
   options.encoding = 'UTF-8'
-  options.compilerArgs << '-Xlint:all' << '-Xlint:unchecked'
+  options.compilerArgs += ['-Xlint:all', '-Xlint:unchecked', 'autovaluegson.defaultCollectionsToEmpty:true']
 }
 
 allprojects {

gradle/dependencies.gradle

@@ -2,7 +2,7 @@ ext {
 
   version = [
       autoValue        : '1.5',
-      autoValueGson    : '0.6.0',
+      autoValueGson    : '0.7.0',
       junit            : '4.12',
       supportLibVersion: '26.1.0',
       gson             : '2.8.2',

services-core/src/test/java/com/mapbox/core/TestUtils.java

@@ -1,6 +1,11 @@
 package com.mapbox.core;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
 import com.google.gson.JsonParser;
+import org.hamcrest.Matchers;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -11,18 +16,14 @@
 import java.io.Serializable;
 import java.util.Scanner;
 
-import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
 public class TestUtils {
 
   public static final double DELTA = 1E-10;
   public static final String ACCESS_TOKEN = "pk.XXX";
 
-  public void compareJson(String json1, String json2) {
+  public void compareJson(String expectedJson, String actualJson) {
     JsonParser parser = new JsonParser();
-    assertEquals(parser.parse(json1), parser.parse(json2));
+    assertThat(parser.parse(actualJson), Matchers.equalTo(parser.parse(expectedJson)));
   }
 
   protected String loadJsonFixture(String filename) throws IOException {

services-geocoding/src/main/java/com/mapbox/api/geocoding/v5/models/CarmenContext.java

@@ -1,10 +1,16 @@
 package com.mapbox.api.geocoding.v5.models;
 
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import com.google.auto.value.AutoValue;
 import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
 import com.google.gson.TypeAdapter;
 import com.google.gson.annotations.SerializedName;
+import com.mapbox.geojson.Geometry;
+import com.mapbox.geojson.Point;
+import com.mapbox.geojson.gson.GeometryDeserializer;
+import com.mapbox.geojson.gson.PointDeserializer;
 
 import java.io.Serializable;
 
@@ -29,6 +35,14 @@ public static Builder builder() {
     return new AutoValue_CarmenContext.Builder();
   }
 
+  @SuppressWarnings("unused")
+  public static CarmenContext fromJson(@NonNull String json) {
+    Gson gson = new GsonBuilder()
+      .registerTypeAdapterFactory(GeocodingAdapterFactory.create())
+      .create();
+    return gson.fromJson(json, CarmenContext.class);
+  }
+
   /**
    * ID of the feature of the form {index}.{id} where index is the id/handle of the data-source
    * that contributed the result.
@@ -99,12 +113,30 @@ public static TypeAdapter<CarmenContext> typeAdapter(Gson gson) {
     return new AutoValue_CarmenContext.GsonTypeAdapter(gson);
   }
 
+  @SuppressWarnings("unused")
+  public String toJson() {
+    Gson gson = new GsonBuilder()
+      .registerTypeAdapterFactory(GeocodingAdapterFactory.create())
+      .create();
+    return gson.toJson(this);
+  }
+
+  /**
+   * Convert current instance values into another Builder to quickly change one or more values.
+   *
+   * @return a new instance of {@link CarmenContext} using the newly defined values
+   * @since 3.0.0
+   */
+  @SuppressWarnings("unused")
+  public abstract Builder toBuilder();
+
   /**
    * This builder can be used to set the values describing the {@link CarmenFeature}.
    *
    * @since 3.0.0
    */
   @AutoValue.Builder
+  @SuppressWarnings("unused")
   public abstract static class Builder {
 
     /**

services-geocoding/src/main/java/com/mapbox/api/geocoding/v5/models/CarmenFeature.java

@@ -3,24 +3,20 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import com.google.auto.value.AutoValue;
-import com.google.gson.FieldNamingPolicy;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonObject;
 import com.google.gson.TypeAdapter;
-import com.google.gson.annotations.Expose;
 import com.google.gson.annotations.SerializedName;
 import com.mapbox.api.geocoding.v5.GeocodingCriteria.GeocodingTypeCriteria;
 import com.mapbox.geojson.BoundingBox;
 import com.mapbox.geojson.Feature;
 import com.mapbox.geojson.Geometry;
 import com.mapbox.geojson.Point;
-import com.mapbox.geojson.gson.BoundingBoxDeserializer;
 import com.mapbox.geojson.gson.BoundingBoxSerializer;
-import com.mapbox.geojson.gson.GeoJsonAdapterFactory;
 import com.mapbox.geojson.gson.GeometryDeserializer;
+import com.mapbox.geojson.gson.GeometryTypeAdapter;
 import com.mapbox.geojson.gson.PointDeserializer;
-import com.mapbox.geojson.gson.PointSerializer;
 
 import java.io.Serializable;
 import java.util.List;
@@ -46,38 +42,40 @@
 @AutoValue
 public abstract class CarmenFeature implements Serializable {
 
-  @Expose
-  @SerializedName("type")
   private static final String TYPE = "Feature";
 
-  /**
-   * Create a new instance of this class by using the {@link Builder} class.
-   *
-   * @return this classes {@link Builder} for creating a new instance
-   * @since 3.0.0
-   */
-  public static Builder builder() {
-    return new AutoValue_CarmenFeature.Builder();
-  }
-
   /**
    * Create a CarmenFeature object from JSON.
    *
    * @param json string of JSON making up a carmen feature
    * @return this class using the defined information in the provided JSON string
    * @since 2.0.0
    */
+  @NonNull
   public static CarmenFeature fromJson(@NonNull String json) {
-    GsonBuilder gson = new GsonBuilder();
-    gson.registerTypeAdapterFactory(GeocodingAdapterFactory.create());
-    gson.registerTypeAdapterFactory(GeoJsonAdapterFactory.create());
-    gson.registerTypeAdapter(Point.class, new PointDeserializer());
-    gson.registerTypeAdapter(BoundingBox.class, new BoundingBoxDeserializer());
-    gson.registerTypeAdapter(Geometry.class, new GeometryDeserializer());
-    return gson.create().fromJson(json, CarmenFeature.class);
+    Gson gson = new GsonBuilder()
+      .registerTypeAdapter(Point.class, new PointDeserializer())
+      .registerTypeAdapter(Geometry.class, new GeometryDeserializer())
+      .registerTypeAdapterFactory(GeocodingAdapterFactory.create())
+      .create();
+    return gson.fromJson(json, CarmenFeature.class);
+  }
+
+  /**
+   * Create a new instance of this class by using the {@link Builder} class.
+   *
+   * @return this classes {@link Builder} for creating a new instance
+   * @since 3.0.0
+   */
+  @NonNull
+  public static Builder builder() {
+    return new AutoValue_CarmenFeature.Builder()
+      .type(TYPE);
   }
 
+  //
   // Feature specific attributes
+  //
 
   /**
    * This describes the TYPE of GeoJson geometry this object is, thus this will always return
@@ -88,9 +86,8 @@ public static CarmenFeature fromJson(@NonNull String json) {
    * @since 1.0.0
    */
   @NonNull
-  public String type() {
-    return TYPE;
-  }
+  @SerializedName("type")
+  public abstract String type();
 
   /**
    * A {@link CarmenFeature} might have a member named {@code bbox} to include information on the
@@ -136,7 +133,9 @@ public String type() {
   @NonNull
   public abstract JsonObject properties();
 
+  //
   // CarmenFeature specific attributes
+  //
 
   /**
    * A string representing the feature in the requested language, if specified.
@@ -281,13 +280,14 @@ public static TypeAdapter<CarmenFeature> typeAdapter(Gson gson) {
    * @return a JSON string which represents this CarmenFeature
    * @since 3.0.0
    */
+  @SuppressWarnings("unused")
   public String toJson() {
-    GsonBuilder gson = new GsonBuilder();
-    gson.registerTypeAdapter(Point.class, new PointSerializer());
-    gson.registerTypeAdapter(BoundingBox.class, new BoundingBoxSerializer());
-    gson.excludeFieldsWithModifiers(java.lang.reflect.Modifier.TRANSIENT);
-    gson.setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES);
-    return gson.create().toJson(this);
+    Gson gson = new GsonBuilder()
+      .registerTypeAdapter(Geometry.class, new GeometryTypeAdapter())
+      .registerTypeAdapter(BoundingBox.class, new BoundingBoxSerializer())
+      .registerTypeAdapterFactory(GeocodingAdapterFactory.create())
+      .create();
+    return gson.toJson(this, CarmenFeature.class);
   }
 
   /**
@@ -296,6 +296,7 @@ public String toJson() {
    * @return a new instance of {@link CarmenFeature} using the newly defined values
    * @since 3.0.0
    */
+  @SuppressWarnings("unused")
   public abstract Builder toBuilder();
 
   /**
@@ -304,8 +305,12 @@ public String toJson() {
    * @since 3.0.0
    */
   @AutoValue.Builder
+  @SuppressWarnings("unused")
   public abstract static class Builder {
 
+    // Type will always be set to "Feature"
+    abstract Builder type(@NonNull String type);
+
     /**
      * A Feature might have a member named {@code bbox} to include information on the coordinate
      * range for it's {@link Feature}s. The value of the bbox member MUST be a list of size 2*n