From 81fe01b34fec705ec86a71e44c81c72c0443d78b Mon Sep 17 00:00:00 2001
From: Matthew Wraith <matt@bitnomial.com>
Date: Fri, 17 Dec 2021 16:44:14 -0800
Subject: [PATCH] Postgres defaults to unix socket (#230)

---
 pkg/driver/postgres/postgres.go      | 10 +++++++++-
 pkg/driver/postgres/postgres_test.go | 20 ++++++++++++++++----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/pkg/driver/postgres/postgres.go b/pkg/driver/postgres/postgres.go
index 1917cb1..60b1333 100644
--- a/pkg/driver/postgres/postgres.go
+++ b/pkg/driver/postgres/postgres.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/url"
+	"runtime"
 	"strings"
 
 	"github.com/amacneil/dbmate/pkg/dbmate"
@@ -48,7 +49,14 @@ func connectionString(u *url.URL) string {
 
 	// default hostname
 	if hostname == "" {
-		hostname = "localhost"
+		switch runtime.GOOS {
+		case "linux":
+			query.Set("host", "/var/run/postgresql")
+		case "darwin", "freebsd", "dragonfly", "openbsd", "netbsd":
+			query.Set("host", "/tmp")
+		default:
+			hostname = "localhost"
+		}
 	}
 
 	// host param overrides url hostname
diff --git a/pkg/driver/postgres/postgres_test.go b/pkg/driver/postgres/postgres_test.go
index f3f8793..1a49ce0 100644
--- a/pkg/driver/postgres/postgres_test.go
+++ b/pkg/driver/postgres/postgres_test.go
@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"net/url"
 	"os"
+	"runtime"
 	"testing"
 
 	"github.com/amacneil/dbmate/pkg/dbmate"
@@ -50,13 +51,24 @@ func TestGetDriver(t *testing.T) {
 	require.Equal(t, "schema_migrations", drv.migrationsTableName)
 }
 
+func defaultConnString() string {
+	switch runtime.GOOS {
+	case "linux":
+		return "postgres://:5432/foo?host=%2Fvar%2Frun%2Fpostgresql"
+	case "darwin", "freebsd", "dragonfly", "openbsd", "netbsd":
+		return "postgres://:5432/foo?host=%2Ftmp"
+	default:
+		return "postgres://localhost:5432/foo"
+	}
+}
+
 func TestConnectionString(t *testing.T) {
 	cases := []struct {
 		input    string
 		expected string
 	}{
 		// defaults
-		{"postgres:///foo", "postgres://localhost:5432/foo"},
+		{"postgres:///foo", defaultConnString()},
 		// support custom url params
 		{"postgres://bob:secret@myhost:1234/foo?bar=baz", "postgres://bob:secret@myhost:1234/foo?bar=baz"},
 		// support `host` and `port` via url params
@@ -85,11 +97,11 @@ func TestConnectionArgsForDump(t *testing.T) {
 		expected []string
 	}{
 		// defaults
-		{"postgres:///foo", []string{"postgres://localhost:5432/foo"}},
+		{"postgres:///foo", []string{defaultConnString()}},
 		// support single schema
-		{"postgres:///foo?search_path=foo", []string{"--schema", "foo", "postgres://localhost:5432/foo"}},
+		{"postgres:///foo?search_path=foo", []string{"--schema", "foo", defaultConnString()}},
 		// support multiple schemas
-		{"postgres:///foo?search_path=foo,public", []string{"--schema", "foo", "--schema", "public", "postgres://localhost:5432/foo"}},
+		{"postgres:///foo?search_path=foo,public", []string{"--schema", "foo", "--schema", "public", defaultConnString()}},
 	}
 
 	for _, c := range cases {