Improve unit tests around Hasresultset and WriteValue (#1006)

* update server tests to use constructor convention from d02e79a

* unit test the nil case of Hasresultset

* unit test WriteValue for OK vs Resultset

* handle nil result correctly, and test nil resultset correctly

* test brevity

Author: stgarrity

mysql/result.go

@@ -36,6 +36,9 @@ func (r *Result) Close() {
 }
 
 func (r *Result) HasResultset() bool {
+	if r == nil {
+		return false
+	}
 	if r.Resultset != nil && len(r.Resultset.Fields) > 0 {
 		return true
 	}

mysql/result_test.go

@@ -9,11 +9,25 @@ import (
 func TestHasResultset_false(t *testing.T) {
 	r := NewResultReserveResultset(0)
 	b := r.HasResultset()
-	require.Equal(t, false, b)
+	require.False(t, b)
 }
 
 func TestHasResultset_true(t *testing.T) {
 	r := NewResultReserveResultset(1)
 	b := r.HasResultset()
-	require.Equal(t, true, b)
+	require.True(t, b)
+}
+
+// this shouldn't happen after d02e79a, but test just in case
+func TestHasResultset_nilset(t *testing.T) {
+	r := NewResultReserveResultset(0)
+	r.Resultset = nil
+	b := r.HasResultset()
+	require.False(t, b)
+}
+
+func TestHasResultset_nil(t *testing.T) {
+	var r *Result
+	b := r.HasResultset()
+	require.False(t, b)
 }

server/resp_test.go

@@ -14,10 +14,9 @@ func TestConnWriteOK(t *testing.T) {
 	clientConn := &mockconn.MockConn{}
 	conn := &Conn{Conn: packet.NewConn(clientConn)}
 
-	result := &mysql.Result{
-		AffectedRows: 1,
-		InsertId:     2,
-	}
+	result := mysql.NewResultReserveResultset(0)
+	result.AffectedRows = 1
+	result.InsertId = 2
 
 	// write ok with insertid and affectedrows set
 	err := conn.writeOK(result)
@@ -229,3 +228,36 @@ func TestConnWriteFieldValues(t *testing.T) {
 	// EOF
 	require.Equal(t, []byte{1, 0, 0, 4, mysql.EOF_HEADER}, clientConn.WriteBuffered[43:])
 }
+
+func TestWriteValue(t *testing.T) {
+	clientConn := &mockconn.MockConn{MultiWrite: true}
+	conn := &Conn{Conn: packet.NewConn(clientConn)}
+
+	// simple OK
+	err := conn.WriteValue(mysql.NewResultReserveResultset(0))
+	require.NoError(t, err)
+	expected := []byte{3, 0, 0, 0, mysql.OK_HEADER, 0, 0}
+	require.Equal(t, expected, clientConn.WriteBuffered)
+
+	// reset write buffer
+	clientConn.WriteBuffered = []byte{}
+
+	// resultset with no rows
+	rs := mysql.NewResultReserveResultset(1)
+	rs.Fields = []*mysql.Field{{Name: []byte("a")}}
+	err = conn.WriteValue(rs)
+	require.NoError(t, err)
+	expected = []byte{1, 0, 0, 1, mysql.MORE_DATE_HEADER}
+	require.Equal(t, expected, clientConn.WriteBuffered[:5])
+
+	// reset write buffer
+	clientConn.WriteBuffered = []byte{}
+
+	// resultset with rows
+	rs.Fields = []*mysql.Field{{Name: []byte("a")}}
+	rs.RowDatas = []mysql.RowData{[]byte{1, 2, 3}}
+	err = conn.WriteValue(rs)
+	require.NoError(t, err)
+	expected = []byte{1, 0, 0, 5, mysql.MORE_DATE_HEADER}
+	require.Equal(t, expected, clientConn.WriteBuffered[:5])
+}

server/server_test.go

@@ -241,30 +241,16 @@ func (h *testHandler) handleQuery(query string, binary bool) (*mysql.Result, err
 		if err != nil {
 			return nil, errors.Trace(err)
 		} else {
-			return &mysql.Result{
-				Status:       0,
-				Warnings:     0,
-				InsertId:     0,
-				AffectedRows: 0,
-				Resultset:    r,
-			}, nil
+			return mysql.NewResult(r), nil
 		}
 	case "insert":
-		return &mysql.Result{
-			Status:       0,
-			Warnings:     0,
-			InsertId:     1,
-			AffectedRows: 0,
-			Resultset:    nil,
-		}, nil
+		res := mysql.NewResultReserveResultset(0)
+		res.InsertId = 1
+		return res, nil
 	case "delete", "update", "replace":
-		return &mysql.Result{
-			Status:       0,
-			Warnings:     0,
-			InsertId:     0,
-			AffectedRows: 1,
-			Resultset:    nil,
-		}, nil
+		res := mysql.NewResultReserveResultset(0)
+		res.AffectedRows = 1
+		return res, nil
 	default:
 		return nil, fmt.Errorf("invalid query %s", query)
 	}