Add WrapperQuery

See
https://www.elastic.co/guide/en/elasticsearch/reference/6.3/query-dsl-wrapper-query.html.

Close #834.

Author: olivere

search_queries_wrapper.go

@@ -0,0 +1,28 @@
+// Copyright 2012-present Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+// WrapperQuery accepts any other query as base64 encoded string.
+//
+// For details, see
+// https://www.elastic.co/guide/en/elasticsearch/reference/6.3/query-dsl-wrapper-query.html.
+type WrapperQuery struct {
+	source string
+}
+
+// NewWrapperQuery creates and initializes a new WrapperQuery.
+func NewWrapperQuery(source string) *WrapperQuery {
+	return &WrapperQuery{source: source}
+}
+
+// Source returns JSON for the query.
+func (q *WrapperQuery) Source() (interface{}, error) {
+	// {"wrapper":{"query":"..."}}
+	source := make(map[string]interface{})
+	tq := make(map[string]interface{})
+	source["wrapper"] = tq
+	tq["query"] = q.source
+	return source, nil
+}

search_queries_wrapper_integration_test.go

@@ -0,0 +1,48 @@
+// Copyright 2012-present Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+)
+
+func TestWrapperQueryIntegration(t *testing.T) {
+	client := setupTestClientAndCreateIndexAndAddDocs(t) //, SetTraceLog(log.New(os.Stdout, "", log.LstdFlags)))
+
+	tq := NewTermQuery("user", "olivere")
+	src, err := tq.Source()
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := json.Marshal(src)
+	if err != nil {
+		t.Fatalf("marshaling to JSON failed: %v", err)
+	}
+	base64string := base64.StdEncoding.EncodeToString(data)
+
+	q := NewWrapperQuery(base64string)
+
+	// Match all should return all documents
+	searchResult, err := client.Search().
+		Index(testIndexName).
+		Query(q).
+		Pretty(true).
+		Do(context.TODO())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if searchResult.Hits == nil {
+		t.Errorf("expected SearchResult.Hits != nil; got nil")
+	}
+	if got, want := searchResult.Hits.TotalHits, int64(2); got != want {
+		t.Errorf("expected SearchResult.Hits.TotalHits = %d; got %d", want, got)
+	}
+	if got, want := len(searchResult.Hits.Hits), 2; got != want {
+		t.Errorf("expected len(SearchResult.Hits.Hits) = %d; got %d", want, got)
+	}
+}

search_queries_wrapper_test.go

@@ -0,0 +1,27 @@
+// Copyright 2012-present Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestWrapperQuery(t *testing.T) {
+	q := NewWrapperQuery("eyJ0ZXJtIiA6IHsgInVzZXIiIDogIktpbWNoeSIgfX0=")
+	src, err := q.Source()
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := json.Marshal(src)
+	if err != nil {
+		t.Fatalf("marshaling to JSON failed: %v", err)
+	}
+	got := string(data)
+	expected := `{"wrapper":{"query":"eyJ0ZXJtIiA6IHsgInVzZXIiIDogIktpbWNoeSIgfX0="}}`
+	if got != expected {
+		t.Errorf("expected\n%s\n,got:\n%s", expected, got)
+	}
+}