Move LoadDataType to pgx.Conn

pgtype/composite_test.go

@@ -2,6 +2,7 @@ package pgtype_test
 
 import (
 	"context"
+	"fmt"
 	"testing"
 
 	pgx "github.com/jackc/pgx/v5"
@@ -23,34 +24,9 @@ create type ct_test as (
 	require.NoError(t, err)
 	defer conn.Exec(context.Background(), "drop type ct_test")
 
-	var oid uint32
-	err = conn.QueryRow(context.Background(), `select 'ct_test'::regtype::oid`).Scan(&oid)
+	dt, err := conn.LoadDataType(context.Background(), "ct_test")
 	require.NoError(t, err)
-
-	defer conn.Exec(context.Background(), "drop type ct_test")
-
-	textDataType, ok := conn.ConnInfo().DataTypeForOID(pgtype.TextOID)
-	require.True(t, ok)
-
-	int4DataType, ok := conn.ConnInfo().DataTypeForOID(pgtype.Int4OID)
-	require.True(t, ok)
-
-	conn.ConnInfo().RegisterDataType(pgtype.DataType{
-		Name: "ct_test",
-		OID:  oid,
-		Codec: &pgtype.CompositeCodec{
-			Fields: []pgtype.CompositeCodecField{
-				{
-					Name:     "a",
-					DataType: textDataType,
-				},
-				{
-					Name:     "b",
-					DataType: int4DataType,
-				},
-			},
-		},
-	})
+	conn.ConnInfo().RegisterDataType(*dt)
 
 	formats := []struct {
 		name string
@@ -74,3 +50,76 @@ create type ct_test as (
 		require.EqualValuesf(t, 42, b, "%v", format.name)
 	}
 }
+
+type point3d struct {
+	X, Y, Z float64
+}
+
+func (p point3d) IsNull() bool {
+	return false
+}
+
+func (p point3d) Index(i int) interface{} {
+	switch i {
+	case 0:
+		return p.X
+	case 1:
+		return p.Y
+	case 2:
+		return p.Z
+	default:
+		panic("invalid index")
+	}
+}
+
+func (p *point3d) ScanNull() error {
+	return fmt.Errorf("cannot scan NULL into point3d")
+}
+
+func (p *point3d) ScanIndex(i int) interface{} {
+	switch i {
+	case 0:
+		return &p.X
+	case 1:
+		return &p.Y
+	case 2:
+		return &p.Z
+	default:
+		panic("invalid index")
+	}
+}
+
+func TestCompositeCodecTranscodeStruct(t *testing.T) {
+	conn := testutil.MustConnectPgx(t)
+	defer testutil.MustCloseContext(t, conn)
+
+	_, err := conn.Exec(context.Background(), `drop type if exists point3d;
+
+create type point3d as (
+	x float8,
+	y float8,
+	z float8
+);`)
+	require.NoError(t, err)
+	defer conn.Exec(context.Background(), "drop type point3d")
+
+	dt, err := conn.LoadDataType(context.Background(), "point3d")
+	require.NoError(t, err)
+	conn.ConnInfo().RegisterDataType(*dt)
+
+	formats := []struct {
+		name string
+		code int16
+	}{
+		{name: "TextFormat", code: pgx.TextFormatCode},
+		{name: "BinaryFormat", code: pgx.BinaryFormatCode},
+	}
+
+	for _, format := range formats {
+		input := point3d{X: 1, Y: 2, Z: 3}
+		var output point3d
+		err := conn.QueryRow(context.Background(), "select $1::point3d", pgx.QueryResultFormats{format.code}, input).Scan(&output)
+		require.NoErrorf(t, err, "%v", format.name)
+		require.Equalf(t, input, output, "%v", format.name)
+	}
+}