Merge branch 'pr/57'

Change-Id: I43df317511acb54e7bc7677751ec51bc3c2e088f

core/option/options.go

@@ -256,6 +256,7 @@ var (
 	_ InsertOptioner            = (*OptOrdered)(nil)
 	_ InsertOptioner            = (*OptWriteConcern)(nil)
 	_ ListDatabasesOptioner     = OptNameOnly(false)
+	_ ListCollectionsOptioner   = OptNameOnly(false)
 	_ ListIndexesOptioner       = OptBatchSize(0)
 	_ ReplaceOptioner           = (*OptBypassDocumentValidation)(nil)
 	_ ReplaceOptioner           = (*OptCollation)(nil)
@@ -734,4 +735,5 @@ func (opt OptNameOnly) Option(d *bson.Document) error {
 	return nil
 }
 
-func (OptNameOnly) listDatabasesOption() {}
+func (OptNameOnly) listDatabasesOption()   {}
+func (OptNameOnly) listCollectionsOption() {}

mongo/database.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mongodb/mongo-go-driver/core/command"
 	"github.com/mongodb/mongo-go-driver/core/description"
 	"github.com/mongodb/mongo-go-driver/core/dispatch"
+	"github.com/mongodb/mongo-go-driver/core/option"
 	"github.com/mongodb/mongo-go-driver/core/readconcern"
 	"github.com/mongodb/mongo-go-driver/core/readpref"
 	"github.com/mongodb/mongo-go-driver/core/writeconcern"
@@ -90,3 +91,21 @@ func (db *Database) Drop(ctx context.Context) error {
 	}
 	return nil
 }
+
+// ListCollections list collections from mongodb database.
+func (db *Database) ListCollections(ctx context.Context, filter *bson.Document, options ...option.ListCollectionsOptioner) (command.Cursor, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	cmd := command.ListCollections{
+		DB:     db.name,
+		Filter: filter,
+		Opts:   options,
+	}
+	cursor, err := dispatch.ListCollections(ctx, cmd, db.client.topology, db.readSelector)
+	if err != nil && !command.IsNotFound(err) {
+		return nil, err
+	}
+	return cursor, nil
+
+}

mongo/database_internal_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"github.com/mongodb/mongo-go-driver/bson"
+	"github.com/mongodb/mongo-go-driver/core/option"
 	"github.com/mongodb/mongo-go-driver/internal/testutil"
 	"github.com/stretchr/testify/require"
 )
@@ -70,3 +71,79 @@ func TestDatabase_Drop(t *testing.T) {
 	require.NotContains(t, list, name)
 
 }
+
+func TestDatabase_ListCollections(t *testing.T) {
+	t.Parallel()
+	dbName := "db_list_collection"
+	db := createTestDatabase(t, &dbName)
+	collName := "list_collections_name"
+	coll := db.Collection(collName)
+	require.Equal(t, coll.Name(), collName)
+	require.NotNil(t, coll)
+	cursor, err := db.ListCollections(context.Background(), nil)
+	require.NoError(t, err)
+
+	next := bson.NewDocument()
+
+	for cursor.Next(context.Background()) {
+		err = cursor.Decode(next)
+		require.NoError(t, err)
+
+		elem, err := next.LookupErr("name")
+		require.NoError(t, err)
+		if elem.Type() != bson.TypeString {
+			t.Errorf("Incorrect type for 'name'. got %v; want %v", elem.Type(), bson.TypeString)
+			t.FailNow()
+		}
+		if elem.StringValue() != collName {
+			t.Errorf("Incorrect collection name. got %s: want %s", elem.StringValue(), collName)
+			t.FailNow()
+		}
+		//Because we run it without nameOnly parameter we should check if another parameter is exist
+		docType, err := next.LookupErr("type")
+		require.NoError(t, err)
+		if docType.StringValue() != "collections" {
+			t.Errorf("Incorrect cursor type. got %s: want %s", docType.StringValue(), "collections")
+			t.FailNow()
+		}
+	}
+	defer func() {
+		err := db.Drop(context.Background())
+		require.NoError(t, err)
+	}()
+}
+
+func TestDatabase_ListCollectionsOptions(t *testing.T) {
+	t.Parallel()
+	dbName := "db_list_collection_options"
+	db := createTestDatabase(t, &dbName)
+	collName := "list_collections_options"
+	coll := db.Collection(collName)
+	require.Equal(t, coll.Name(), collName)
+	require.NotNil(t, coll)
+	cursor, err := db.ListCollections(context.Background(), nil, option.OptNameOnly(true))
+	require.NoError(t, err)
+
+	next := bson.NewDocument()
+
+	for cursor.Next(context.Background()) {
+		err = cursor.Decode(next)
+		require.NoError(t, err)
+
+		elem, err := next.LookupErr("name")
+		require.NoError(t, err)
+
+		if elem.StringValue() != collName {
+			t.Errorf("Incorrect collection name. got %s: want %s", elem.StringValue(), collName)
+			t.FailNow()
+		}
+
+		//Because we run it with name only parameter we should check that there are no other parameters
+		_, err = next.LookupErr("type")
+		require.Error(t, err)
+	}
+	defer func() {
+		err := db.Drop(context.Background())
+		require.NoError(t, err)
+	}()
+}