From 1334d45d7129a0419659bc6803e7a6316307b701 Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Tue, 8 Feb 2022 11:35:40 -0600
Subject: [PATCH] Parse array header to empty slices instead of nils

---
 pgtype/array.go       | 11 ++++++-----
 pgtype/array_codec.go | 12 ------------
 pgtype/array_test.go  |  6 +++---
 3 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/pgtype/array.go b/pgtype/array.go
index 0e8e31a0..d1a78e64 100644
--- a/pgtype/array.go
+++ b/pgtype/array.go
@@ -58,9 +58,7 @@ func (dst *ArrayHeader) DecodeBinary(ci *ConnInfo, src []byte) (int, error) {
 	dst.ElementOID = binary.BigEndian.Uint32(src[rp:])
 	rp += 4
 
-	if numDims > 0 {
-		dst.Dimensions = make([]ArrayDimension, numDims)
-	}
+	dst.Dimensions = make([]ArrayDimension, numDims)
 	if len(src) < 12+numDims*8 {
 		return 0, fmt.Errorf("array header too short for %d dimensions: %d", numDims, len(src))
 	}
@@ -101,7 +99,11 @@ type UntypedTextArray struct {
 }
 
 func ParseUntypedTextArray(src string) (*UntypedTextArray, error) {
-	dst := &UntypedTextArray{}
+	dst := &UntypedTextArray{
+		Elements:   []string{},
+		Quoted:     []bool{},
+		Dimensions: []ArrayDimension{},
+	}
 
 	buf := bytes.NewBufferString(src)
 
@@ -234,7 +236,6 @@ func ParseUntypedTextArray(src string) (*UntypedTextArray, error) {
 	}
 
 	if len(dst.Elements) == 0 {
-		dst.Dimensions = nil
 	} else if len(explicitDimensions) > 0 {
 		dst.Dimensions = explicitDimensions
 	} else {
diff --git a/pgtype/array_codec.go b/pgtype/array_codec.go
index 94d24fc9..f23d8e3b 100644
--- a/pgtype/array_codec.go
+++ b/pgtype/array_codec.go
@@ -238,12 +238,6 @@ func (c *ArrayCodec) decodeBinary(ci *ConnInfo, arrayOID uint32, src []byte, arr
 		return err
 	}
 
-	// TODO - ArrayHeader.DecodeBinary should do this. But doing this there breaks old array code. Leave until old code
-	// can be removed.
-	if arrayHeader.Dimensions == nil {
-		arrayHeader.Dimensions = []ArrayDimension{}
-	}
-
 	err = array.SetDimensions(arrayHeader.Dimensions)
 	if err != nil {
 		return err
@@ -283,12 +277,6 @@ func (c *ArrayCodec) decodeText(ci *ConnInfo, arrayOID uint32, src []byte, array
 		return err
 	}
 
-	// TODO - ParseUntypedTextArray should do this. But doing this there breaks old array code. Leave until old code
-	// can be removed.
-	if uta.Dimensions == nil {
-		uta.Dimensions = []ArrayDimension{}
-	}
-
 	err = array.SetDimensions(uta.Dimensions)
 	if err != nil {
 		return err
diff --git a/pgtype/array_test.go b/pgtype/array_test.go
index 82f5f229..8043e12f 100644
--- a/pgtype/array_test.go
+++ b/pgtype/array_test.go
@@ -15,9 +15,9 @@ func TestParseUntypedTextArray(t *testing.T) {
 		{
 			source: "{}",
 			result: pgtype.UntypedTextArray{
-				Elements:   nil,
-				Quoted:     nil,
-				Dimensions: nil,
+				Elements:   []string{},
+				Quoted:     []bool{},
+				Dimensions: []pgtype.ArrayDimension{},
 			},
 		},
 		{