From d24135cb8039bf8c8e9289a443fdab6a4d7ba88c Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@gmail.com>
Date: Thu, 27 Apr 2023 18:30:30 -0400
Subject: [PATCH] Add support for NamedValueChecker interface

Added in 1.9: https://go.dev/doc/go1.9#minor_library_changes.
---
 array.go          |  7 ++---
 conn_go19.go      | 35 +++++++++++++++++++++++++
 conn_go19_test.go | 66 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 105 insertions(+), 3 deletions(-)
 create mode 100644 conn_go19.go
 create mode 100644 conn_go19_test.go

diff --git a/array.go b/array.go
index 39c8f7e2..9957c048 100644
--- a/array.go
+++ b/array.go
@@ -19,10 +19,11 @@ var typeSQLScanner = reflect.TypeOf((*sql.Scanner)(nil)).Elem()
 // slice of any dimension.
 //
 // For example:
-//  db.Query(`SELECT * FROM t WHERE id = ANY($1)`, pq.Array([]int{235, 401}))
 //
-//  var x []sql.NullInt64
-//  db.QueryRow(`SELECT ARRAY[235, 401]`).Scan(pq.Array(&x))
+//	db.Query(`SELECT * FROM t WHERE id = ANY($1)`, pq.Array([]int{235, 401}))
+//
+//	var x []sql.NullInt64
+//	db.QueryRow(`SELECT ARRAY[235, 401]`).Scan(pq.Array(&x))
 //
 // Scanning multi-dimensional arrays is not supported.  Arrays where the lower
 // bound is not one (such as `[0:0]={1}') are not supported.
diff --git a/conn_go19.go b/conn_go19.go
new file mode 100644
index 00000000..e34705e1
--- /dev/null
+++ b/conn_go19.go
@@ -0,0 +1,35 @@
+//go:build go1.9
+// +build go1.9
+
+package pq
+
+import (
+	"database/sql/driver"
+	"reflect"
+)
+
+var _ driver.NamedValueChecker = (*conn)(nil)
+
+func (c *conn) CheckNamedValue(nv *driver.NamedValue) error {
+	if _, ok := nv.Value.(driver.Valuer); ok {
+		// Ignore Valuer, for backward compatiblity with pq.Array()
+		return driver.ErrSkip
+	}
+
+	// Ignoring []byte / []uint8
+	if _, ok := nv.Value.([]uint8); ok {
+		return driver.ErrSkip
+	}
+
+	v := reflect.ValueOf(nv.Value)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	if v.Kind() == reflect.Slice {
+		var err error
+		nv.Value, err = Array(nv.Value).Value()
+		return err
+	}
+
+	return driver.ErrSkip
+}
diff --git a/conn_go19_test.go b/conn_go19_test.go
new file mode 100644
index 00000000..1552261b
--- /dev/null
+++ b/conn_go19_test.go
@@ -0,0 +1,66 @@
+//go:build go1.9
+// +build go1.9
+
+package pq
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestArrayArg(t *testing.T) {
+	db := openTestConn(t)
+	defer db.Close()
+
+	for _, tc := range []struct {
+		in, out interface{}
+	}{
+		{
+			in:  []int{245, 231},
+			out: []int64{245, 231},
+		},
+		{
+			in:  &[]int{245, 231},
+			out: []int64{245, 231},
+		},
+		{
+			in: []int64{245, 231},
+		},
+		{
+			in:  &[]int64{245, 231},
+			out: []int64{245, 231},
+		},
+	} {
+		t.Run(fmt.Sprintf("%#v", tc.in), func(t *testing.T) {
+			r, err := db.Query("SELECT $1::int[]", tc.in)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer r.Close()
+
+			if !r.Next() {
+				if r.Err() != nil {
+					t.Fatal(r.Err())
+				}
+				t.Fatal("expected row")
+			}
+
+			defer func() {
+				if r.Next() {
+					t.Fatal("unexpected row")
+				}
+			}()
+
+			got := reflect.New(reflect.TypeOf(tc.out)).Elem()
+			if err := r.Scan(got.Interface()); err != nil {
+				t.Fatal(err)
+			}
+
+			if !reflect.DeepEqual(tc.out, got.Interface()) {
+				t.Errorf("got %v, want %v", got, tc.out)
+			}
+		})
+	}
+
+}