Simplify GeoPoint

This commit simplifies usage of `GeoPoint`. It can now be used like

  doc.Location = geoPoint

instead of

  doc.Location = geoPoint.Source()

Furthermore, this commit adds tests to illustrate searching with
`GeoPoint` and `GeoDistanceQuery`.

Close #813

Author: olivere

geo_point.go

@@ -5,6 +5,7 @@
 package elastic
 
 import (
+	"encoding/json"
 	"fmt"
 	"strconv"
 	"strings"
@@ -24,6 +25,11 @@ func (pt *GeoPoint) Source() map[string]float64 {
 	}
 }
 
+// MarshalJSON encodes the GeoPoint to JSON.
+func (pt *GeoPoint) MarshalJSON() ([]byte, error) {
+	return json.Marshal(pt.Source())
+}
+
 // GeoPointFromLatLon initializes a new GeoPoint by latitude and longitude.
 func GeoPointFromLatLon(lat, lon float64) *GeoPoint {
 	return &GeoPoint{Lat: lat, Lon: lon}

geo_point_test.go

@@ -5,6 +5,7 @@
 package elastic
 
 import (
+	"context"
 	"encoding/json"
 	"testing"
 )
@@ -22,3 +23,99 @@ func TestGeoPointSource(t *testing.T) {
 		t.Errorf("expected\n%s\n,got:\n%s", expected, got)
 	}
 }
+
+func TestGeoPointMarshalJSON(t *testing.T) {
+	pt := GeoPoint{Lat: 40, Lon: -70}
+
+	data, err := json.Marshal(pt)
+	if err != nil {
+		t.Fatalf("marshaling to JSON failed: %v", err)
+	}
+	got := string(data)
+	expected := `{"lat":40,"lon":-70}`
+	if got != expected {
+		t.Errorf("expected\n%s\n,got:\n%s", expected, got)
+	}
+}
+
+func TestGeoPointIndexAndSearch(t *testing.T) {
+	client := setupTestClient(t) // , SetTraceLog(log.New(os.Stdout, "", 0)))
+
+	// Create index
+	mapping := `
+	{
+		"settings":{
+			"number_of_shards":1,
+			"number_of_replicas":0
+		},
+		"mappings":{
+			"doc":{
+				"properties":{
+					"name":{
+						"type":"keyword"
+					},
+					"location":{
+						"type":"geo_point"
+					}
+				}
+			}
+		}
+	}
+`
+	createIndex, err := client.CreateIndex(testIndexName).Body(mapping).Do(context.TODO())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if createIndex == nil {
+		t.Errorf("expected result to be != nil; got: %v", createIndex)
+	}
+
+	// Add document
+	type City struct {
+		Name     string    `json:"name"`
+		Location *GeoPoint `json:"location"`
+	}
+	munich := &City{
+		Name:     "München",
+		Location: GeoPointFromLatLon(48.137154, 11.576124),
+	}
+	_, err = client.Index().Index(testIndexName).Type("doc").Id("1").BodyJson(&munich).Do(context.TODO())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Flush
+	_, err = client.Flush().Index(testIndexName).Do(context.TODO())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Get document
+	q := NewGeoDistanceQuery("location")
+	q = q.GeoPoint(GeoPointFromLatLon(48, 11))
+	q = q.Distance("50km")
+	res, err := client.
+		Search(testIndexName).
+		Type("doc").
+		Query(q).
+		Do(context.TODO())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want, have := int64(1), res.TotalHits(); want != have {
+		t.Fatalf("TotalHits: want %d, have %d", want, have)
+	}
+	var doc City
+	if err := json.Unmarshal(*res.Hits.Hits[0].Source, &doc); err != nil {
+		t.Fatal(err)
+	}
+	if want, have := munich.Name, doc.Name; want != have {
+		t.Fatalf("Name: want %q, have %q", want, have)
+	}
+	if want, have := munich.Location.Lat, doc.Location.Lat; want != have {
+		t.Fatalf("Lat: want %v, have %v", want, have)
+	}
+	if want, have := munich.Location.Lon, doc.Location.Lon; want != have {
+		t.Fatalf("Lon: want %v, have %v", want, have)
+	}
+}