From 7212979419c022698b611082d621c1edcd6d7499 Mon Sep 17 00:00:00 2001
From: Chris Seto <chriskseto@gmail.com>
Date: Fri, 13 May 2022 17:26:27 -0400
Subject: [PATCH] fix: support defaultifempty on struct and array types

    Prior to this commit, defaultifempty would not appropriately detect
    the "emptiness" of struct types nor non-zero length array types.
    This was notable for nullable types when used as values, such as
    sql.NullString, and gofrs/uuid, which is defined as [16]byte,
    respectively.
---
 internal/util/reflect.go      |  6 ++++-
 internal/util/reflect_test.go | 41 +++++++++++++++++++----------------
 2 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/internal/util/reflect.go b/internal/util/reflect.go
index bc18b8bd..1116f276 100644
--- a/internal/util/reflect.go
+++ b/internal/util/reflect.go
@@ -64,7 +64,9 @@ func IsPointer(k reflect.Kind) bool {
 
 func IsEmptyValue(v reflect.Value) bool {
 	switch v.Kind() {
-	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+	case reflect.Array:
+		return v.IsZero()
+	case reflect.Map, reflect.Slice, reflect.String:
 		return v.Len() == 0
 	case reflect.Bool:
 		return !v.Bool()
@@ -76,6 +78,8 @@ func IsEmptyValue(v reflect.Value) bool {
 		return v.Float() == 0
 	case reflect.Interface, reflect.Ptr:
 		return v.IsNil()
+	case reflect.Struct:
+		return v.IsZero()
 	case reflect.Invalid:
 		return true
 	default:
diff --git a/internal/util/reflect_test.go b/internal/util/reflect_test.go
index e461add7..2baf27d5 100644
--- a/internal/util/reflect_test.go
+++ b/internal/util/reflect_test.go
@@ -58,25 +58,26 @@ type (
 		str string
 	}
 	TestStruct struct {
-		arr  [0]string
-		slc  []string
-		mp   map[string]interface{}
-		str  string
-		bl   bool
-		i    int
-		i8   int8
-		i16  int16
-		i32  int32
-		i64  int64
-		ui   uint
-		ui8  uint8
-		ui16 uint16
-		ui32 uint32
-		ui64 uint64
-		f32  float32
-		f64  float64
-		intr TestInterface
-		ptr  *sql.NullString
+		arr      [1]string
+		slc      []string
+		mp       map[string]interface{}
+		str      string
+		bl       bool
+		i        int
+		i8       int8
+		i16      int16
+		i32      int32
+		i64      int64
+		ui       uint
+		ui8      uint8
+		ui16     uint16
+		ui32     uint32
+		ui64     uint64
+		f32      float32
+		f64      float64
+		intr     TestInterface
+		ptr      *sql.NullString
+		nullable sql.NullString
 	}
 )
 
@@ -342,6 +343,7 @@ func (rt *reflectTest) TestIsEmptyValue_emptyValues() {
 	rt.True(util.IsEmptyValue(reflect.ValueOf(ts.f64)))
 	rt.True(util.IsEmptyValue(reflect.ValueOf(ts.intr)))
 	rt.True(util.IsEmptyValue(reflect.ValueOf(ts.ptr)))
+	rt.True(util.IsEmptyValue(reflect.ValueOf(ts.nullable)))
 }
 
 func (rt *reflectTest) TestIsEmptyValue_validValues() {
@@ -365,6 +367,7 @@ func (rt *reflectTest) TestIsEmptyValue_validValues() {
 	rt.False(util.IsEmptyValue(reflect.ValueOf(float64(0.2))))
 	rt.False(util.IsEmptyValue(reflect.ValueOf(ts.intr)))
 	rt.False(util.IsEmptyValue(reflect.ValueOf(&TestStruct{str: "a"})))
+	rt.False(util.IsEmptyValue(reflect.ValueOf(sql.NullString{Valid: true})))
 }
 
 func (rt *reflectTest) TestColumnRename() {