Add test and fix bugs

dgraph/cmd/alpha/upsert_test.go

@@ -17,13 +17,16 @@
 package alpha
 
 import (
+	"context"
 	"fmt"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
 	"testing"
 
 	"github.com/dgraph-io/dgo/v2"
+	"github.com/dgraph-io/dgo/v2/protos/api"
 	"github.com/dgraph-io/dgraph/testutil"
 	"github.com/stretchr/testify/require"
 )
@@ -2065,3 +2068,65 @@ upsert {
 	// of vars.
 	require.Equal(t, 0, len(mr.vars))
 }
+
+func TestMultiMutationEmptyRequest(t *testing.T) {
+	// We are using the dgo client in this test here to test the grpc interface
+	dg, err := testutil.DgraphClientWithGroot("localhost:9180")
+	require.NoError(t, err, "error while getting a dgraph client")
+
+	require.NoError(t, dg.Alter(context.Background(), &api.Operation{
+		DropOp: api.Operation_ALL,
+	}))
+	require.NoError(t, dg.Alter(context.Background(), &api.Operation{
+		Schema: `
+      name: string @index(exact) .
+      branch: string .
+      amount: float .
+    `,
+	}))
+
+	req := &api.Request{}
+	_, err = dg.NewTxn().Do(context.Background(), req)
+	require.Contains(t, strings.ToLower(err.Error()), "empty request")
+}
+
+// This mutation (upsert) has one independent query and one independent mutation.
+func TestMultiMutationNoUpsert(t *testing.T) {
+	dg, err := testutil.DgraphClientWithGroot("localhost:9180")
+	require.NoError(t, err, "error while getting a dgraph client")
+
+	require.NoError(t, dg.Alter(context.Background(), &api.Operation{
+		DropOp: api.Operation_ALL,
+	}))
+	require.NoError(t, dg.Alter(context.Background(), &api.Operation{
+		Schema: `
+      email: string @index(exact) .
+      works_for: string @index(exact) .
+      works_with: [uid] .
+    `,
+	}))
+
+	req := &api.Request{
+		Query: `
+      query {
+        empty(func: eq(works_for, "company1")) {
+          uid
+          name
+        }
+      }`,
+		Mutations: []*api.Mutation{
+			&api.Mutation{
+				SetNquads: []byte(`
+        _:user1 <name> "user1" .
+        _:user1 <email> "user1@company1.io" .
+        _:user1 <works_for> "company1" .`),
+			},
+		},
+		CommitNow: true,
+	}
+	resp, err := dg.NewTxn().Do(context.Background(), req)
+	require.NoError(t, err)
+	sort.Strings(resp.Txn.Preds)
+	require.Equal(t, []string{"1-email", "1-name", "1-works_for"}, resp.Txn.Preds)
+	testutil.CompareJSON(t, `{"empty": []}`, string(resp.Json))
+}

edgraph/server.go

@@ -522,8 +522,8 @@ func (s *Server) doQuery(ctx context.Context, req *api.Request, authorize int) (
 
 	span.Annotatef(nil, "Request received: %v", req)
 	if len(req.Query) == 0 && len(req.Mutations) == 0 {
-		span.Annotate(nil, "Empty request")
-		return nil, errors.Errorf("Empty request")
+		span.Annotate(nil, "empty request")
+		return nil, errors.Errorf("empty request")
 	}
 
 	qc := &queryContext{
@@ -544,8 +544,18 @@ func (s *Server) doQuery(ctx context.Context, req *api.Request, authorize int) (
 		}
 	}
 
-	if resp, rerr = processQuery(ctx, qc); rerr != nil {
-		return
+	if qc.req.StartTs == 0 {
+		start := time.Now()
+		qc.req.StartTs = State.getTimestamp(qc.req.ReadOnly)
+		qc.latency.AssignTimestamp = time.Since(start)
+	}
+
+	if qc.req.Query != "" {
+		if resp, rerr = processQuery(ctx, qc); rerr != nil {
+			return
+		}
+	} else {
+		resp = &api.Response{}
 	}
 
 	if isMutation {
@@ -588,6 +598,9 @@ func parseRequest(qc *queryContext) error {
 
 	// updating queries to include dummy variables for conditional upsert
 	upsertQuery := buildUpsertQuery(qc)
+	if upsertQuery == "" {
+		return nil
+	}
 
 	// parsing the updated query
 	var err error
@@ -694,12 +707,6 @@ func processQuery(ctx context.Context, qc *queryContext) (*api.Response, error)
 		qr.Cache = worker.NoCache
 	}
 
-	if qc.req.StartTs == 0 {
-		assignTimestampStart := time.Now()
-		qc.req.StartTs = State.getTimestamp(qc.req.ReadOnly)
-		qc.latency.AssignTimestamp = time.Since(assignTimestampStart)
-	}
-
 	qr.ReadTs = qc.req.StartTs
 	resp := &api.Response{}
 	resp.Txn = &api.TxnContext{StartTs: qc.req.StartTs}