ConnectionParameters.Socket now refers to socket directory

This makes PGX behave more like libpq

* But for backward compatibility still accept complete file names.

connection.go

@@ -16,12 +16,15 @@ import (
 	"io/ioutil"
 	"net"
 	"os/user"
+	"path/filepath"
+	"strconv"
+	"strings"
 	"time"
 )
 
 // ConnectionParameters contains all the options used to establish a connection.
 type ConnectionParameters struct {
-	Socket     string // path to unix domain socket (e.g. /private/tmp/.s.PGSQL.5432)
+	Socket     string // path to unix domain socket directory (e.g. /private/tmp)
 	Host       string // url (e.g. localhost)
 	Port       uint16 // default: 5432
 	Database   string
@@ -126,8 +129,14 @@ func Connect(parameters ConnectionParameters) (c *Connection, err error) {
 	}
 
 	if c.parameters.Socket != "" {
-		c.logger.Info(fmt.Sprintf("Dialing PostgreSQL server at socket: %s", c.parameters.Socket))
+		// For backward compatibility accept socket file paths -- but directories are now preferred
-		c.conn, err = net.Dial("unix", c.parameters.Socket)
+		socket := c.parameters.Socket
+		if !strings.Contains(socket, "/.s.PGSQL.") {
+			socket = filepath.Join(socket, ".s.PGSQL.") + strconv.FormatInt(int64(c.parameters.Port), 10)
+		}
+
+		c.logger.Info(fmt.Sprintf("Dialing PostgreSQL server at socket: %s", socket))
+		c.conn, err = net.Dial("unix", socket)
 		if err != nil {
 			c.logger.Error(fmt.Sprintf("Connection failed: %v", err))
 			return nil, err

connection_settings_test.go.example

@@ -15,7 +15,7 @@ var noPasswordConnectionParameters *pgx.ConnectionParameters = nil
 var invalidUserConnectionParameters *pgx.ConnectionParameters = nil
 
 // var tcpConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Host: "127.0.0.1", User: "pgx_md5", Password: "secret", Database: "pgx_test"}
-// var unixSocketConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Socket: "/private/tmp/.s.PGSQL.5432", User: "pgx_none", Database: "pgx_test"}
+// var unixSocketConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Socket: "/private/tmp", User: "pgx_none", Database: "pgx_test"}
 // var md5ConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Host: "127.0.0.1", User: "pgx_md5", Password: "secret", Database: "pgx_test"}
 // var plainPasswordConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Host: "127.0.0.1", User: "pgx_pw", Password: "secret", Database: "pgx_test"}
 // var noPasswordConnectionParameters *pgx.ConnectionParameters = &pgx.ConnectionParameters{Host: "127.0.0.1", User: "pgx_none", Database: "pgx_test"}

connection_test.go

@@ -44,7 +44,8 @@ func TestConnect(t *testing.T) {
 	}
 }
 
-func TestConnectWithUnixSocket(t *testing.T) {
+func TestConnectWithUnixSocketDirectory(t *testing.T) {
+	// /.s.PGSQL.5432
 	if unixSocketConnectionParameters == nil {
 		return
 	}
@@ -60,6 +61,24 @@ func TestConnectWithUnixSocket(t *testing.T) {
 	}
 }
 
+func TestConnectWithUnixSocketFile(t *testing.T) {
+	if unixSocketConnectionParameters == nil {
+		return
+	}
+
+	connParams := *unixSocketConnectionParameters
+	connParams.Socket = connParams.Socket + "/.s.PGSQL.5432"
+	conn, err := pgx.Connect(connParams)
+	if err != nil {
+		t.Fatalf("Unable to establish connection: %v", err)
+	}
+
+	err = conn.Close()
+	if err != nil {
+		t.Fatal("Unable to close connection")
+	}
+}
+
 func TestConnectWithTcp(t *testing.T) {
 	if tcpConnectionParameters == nil {
 		return