ScatterCon results observer tests

Signed-off-by: Rafer Hazen <[email protected]>

go/vt/vtgate/legacy_scatter_conn_test.go

@@ -369,6 +369,14 @@ func executeOnShardsReturnsErr(t *testing.T, ctx context.Context, res *srvtopo.R
 	return vterrors.Aggregate(errs)
 }
 
+type recordingResultsObserver struct {
+	recorded []*sqltypes.Result
+}
+
+func (o *recordingResultsObserver) observe(result *sqltypes.Result) {
+	o.recorded = append(o.recorded, result)
+}
+
 func TestMultiExecs(t *testing.T) {
 	ctx := utils.LeakCheckContext(t)
 	createSandbox("TestMultiExecs")
@@ -409,9 +417,17 @@ func TestMultiExecs(t *testing.T) {
 			},
 		},
 	}
+	results := []*sqltypes.Result{
+		{Info: "r0"},
+		{Info: "r1"},
+	}
+	sbc0.SetResults(results[0:1])
+	sbc1.SetResults(results[1:2])
+
+	observer := recordingResultsObserver{}
 
 	session := NewSafeSession(&vtgatepb.Session{})
-	_, err := sc.ExecuteMultiShard(ctx, nil, rss, queries, session, false, false, nullResultsObserver{})
+	_, err := sc.ExecuteMultiShard(ctx, nil, rss, queries, session, false, false, &observer)
 	require.NoError(t, vterrors.Aggregate(err))
 	if len(sbc0.Queries) == 0 || len(sbc1.Queries) == 0 {
 		t.Fatalf("didn't get expected query")
@@ -428,8 +444,12 @@ func TestMultiExecs(t *testing.T) {
 	if !reflect.DeepEqual(sbc1.Queries[0].BindVariables, wantVars1) {
 		t.Errorf("got %+v, want %+v", sbc0.Queries[0].BindVariables, wantVars1)
 	}
+	assert.ElementsMatch(t, results, observer.recorded)
+
 	sbc0.Queries = nil
 	sbc1.Queries = nil
+	sbc0.SetResults(results[0:1])
+	sbc1.SetResults(results[1:2])
 
 	rss = []*srvtopo.ResolvedShard{
 		{
@@ -455,15 +475,18 @@ func TestMultiExecs(t *testing.T) {
 			"bv1": sqltypes.Int64BindVariable(1),
 		},
 	}
+
+	observer = recordingResultsObserver{}
 	_ = sc.StreamExecuteMulti(ctx, nil, "query", rss, bvs, session, false /* autocommit */, func(*sqltypes.Result) error {
 		return nil
-	}, nullResultsObserver{})
+	}, &observer)
 	if !reflect.DeepEqual(sbc0.Queries[0].BindVariables, wantVars0) {
 		t.Errorf("got %+v, want %+v", sbc0.Queries[0].BindVariables, wantVars0)
 	}
 	if !reflect.DeepEqual(sbc1.Queries[0].BindVariables, wantVars1) {
 		t.Errorf("got %+v, want %+v", sbc0.Queries[0].BindVariables, wantVars1)
 	}
+	assert.ElementsMatch(t, results, observer.recorded)
 }
 
 func TestScatterConnSingleDB(t *testing.T) {