From bc188140f0b03bd6fecbf956839ea8dcf0321320 Mon Sep 17 00:00:00 2001
From: mavolin <48887425+mavolin@users.noreply.github.com>
Date: Mon, 11 May 2020 23:32:22 +0200
Subject: [PATCH] Utils: add NullableX types in option

---
 utils/json/nullable/bool.go     | 14 ------
 utils/json/nullable/nullable.go |  2 -
 utils/json/nullable/number.go   | 25 ----------
 utils/json/nullable/string.go   | 12 -----
 utils/json/option/bool.go       | 47 ++++++++++++++++++
 utils/json/option/number.go     | 88 +++++++++++++++++++++++++++++++++
 utils/json/option/string.go     | 47 ++++++++++++++++--
 7 files changed, 179 insertions(+), 56 deletions(-)
 delete mode 100644 utils/json/nullable/bool.go
 delete mode 100644 utils/json/nullable/nullable.go
 delete mode 100644 utils/json/nullable/number.go
 delete mode 100644 utils/json/nullable/string.go

diff --git a/utils/json/nullable/bool.go b/utils/json/nullable/bool.go
deleted file mode 100644
index 0f76d29..0000000
--- a/utils/json/nullable/bool.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package nullable
-
-// Bool is a nullable version of a bool.
-type Bool *bool
-
-var (
-	True  = newBool(true)
-	False = newBool(false)
-)
-
-// newBool creates a new Bool with the value of the passed bool.
-func newBool(b bool) Bool {
-	return &b
-}
diff --git a/utils/json/nullable/nullable.go b/utils/json/nullable/nullable.go
deleted file mode 100644
index dab82ee..0000000
--- a/utils/json/nullable/nullable.go
+++ /dev/null
@@ -1,2 +0,0 @@
-// Package nullable provides nullable types that get serialized to JSON null.
-package nullable
diff --git a/utils/json/nullable/number.go b/utils/json/nullable/number.go
deleted file mode 100644
index 97ac219..0000000
--- a/utils/json/nullable/number.go
+++ /dev/null
@@ -1,25 +0,0 @@
-package nullable
-
-type (
-	// Uint is a nullable version of an unsigned integer (uint).
-	Uint *uint
-	// Int is a nullable version of an integer (int).
-	Int *int
-)
-
-var (
-	// ZeroUint is a Uint with 0 as value.
-	ZeroUint = NewUint(0)
-	// ZeroInt is an Int with 0 as value.
-	ZeroInt = NewInt(0)
-)
-
-// NewUint creates a new Uint using the value of the passed uint.
-func NewUint(u uint) Uint {
-	return &u
-}
-
-// NewInt creates a new Int using the value of the passed int.
-func NewInt(i int) Int {
-	return &i
-}
diff --git a/utils/json/nullable/string.go b/utils/json/nullable/string.go
deleted file mode 100644
index e3eaefa..0000000
--- a/utils/json/nullable/string.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package nullable
-
-// String is a nullable version of a string.
-type String *string
-
-// EmptyString is a zero-length string.
-var EmptyString = NewString("")
-
-// NewString creates a new String with the value of the passed string.
-func NewString(s string) String {
-	return &s
-}
diff --git a/utils/json/option/bool.go b/utils/json/option/bool.go
index 8e3482f..b28b146 100644
--- a/utils/json/option/bool.go
+++ b/utils/json/option/bool.go
@@ -1,5 +1,9 @@
 package option
 
+import "strconv"
+
+// ================================ Bool ================================
+
 // Bool is the option type for bool.
 type Bool *bool
 
@@ -10,3 +14,46 @@ var (
 
 // newBool creates a new Bool with the value of the passed bool.
 func newBool(b bool) Bool { return &b }
+
+// ================================ NullableBool ================================
+
+// NullableBool is the nullable type for bool.
+type NullableBool = *nullableBool
+
+type nullableBool struct {
+	Val  bool
+	Init bool
+}
+
+var (
+	// NullBool serializes to JSON null.
+	NullBool     = &nullableBool{}
+	NullableTrue = &nullableBool{
+		Val:  true,
+		Init: true,
+	}
+	NullableFalse = &nullableBool{
+		Val:  false,
+		Init: true,
+	}
+)
+
+func (b nullableBool) MarshalJSON() ([]byte, error) {
+	if !b.Init {
+		return []byte("null"), nil
+	}
+	return []byte(strconv.FormatBool(b.Val)), nil
+}
+
+func (b *nullableBool) UnmarshalJSON(json []byte) (err error) {
+	s := string(json)
+
+	if s == "null" {
+		b.Init = false
+		return
+	}
+
+	b.Val, err = strconv.ParseBool(s)
+
+	return
+}
diff --git a/utils/json/option/number.go b/utils/json/option/number.go
index f8a5b18..76a69fe 100644
--- a/utils/json/option/number.go
+++ b/utils/json/option/number.go
@@ -1,5 +1,7 @@
 package option
 
+import "strconv"
+
 // ================================ Uint ================================
 
 // Uint is the option type for unsigned integers (uint).
@@ -21,3 +23,89 @@ var ZeroInt = NewInt(0)
 
 // NewInt creates a new Int using the value of the passed int.
 func NewInt(i int) Int { return &i }
+
+// ================================ NullableUint ================================
+
+// NullableUint is a nullable version of an unsigned integer (uint).
+type NullableUint = *nullableUint
+
+type nullableUint struct {
+	Val  uint
+	Init bool
+}
+
+// NullUint serializes to JSON null.
+var NullUint = &nullableUint{}
+
+// NewUint creates a new non-null NullableUint using the value of the passed uint.
+func NewNullableUint(v uint) NullableUint {
+	return &nullableUint{
+		Val:  v,
+		Init: true,
+	}
+}
+
+func (u nullableUint) MarshalJSON() ([]byte, error) {
+	if !u.Init {
+		return []byte("null"), nil
+	}
+	return []byte(strconv.FormatUint(uint64(u.Val), 10)), nil
+}
+
+func (u *nullableUint) UnmarshalJSON(json []byte) error {
+	s := string(json)
+
+	if s == "null" {
+		u.Init = false
+		return nil
+	}
+
+	v, err := strconv.ParseUint(s, 10, 64)
+
+	u.Val = uint(v)
+
+	return err
+}
+
+// ================================ NullableInt ================================
+
+// NullableInt is a nullable version of an integer (int).
+type NullableInt *nullableInt
+
+type nullableInt struct {
+	Val  int
+	Init bool
+}
+
+// NullUint serializes to JSON null.
+var NullInt = &nullableUint{}
+
+// NewInt creates a new non-null NullableInt using the value of the passed int.
+func NewNullableInt(v int) NullableInt {
+	return &nullableInt{
+		Val:  v,
+		Init: true,
+	}
+}
+
+func (i nullableInt) MarshalJSON() ([]byte, error) {
+	if !i.Init {
+		return []byte("null"), nil
+	}
+	return []byte(strconv.FormatUint(uint64(i.Val), 10)), nil
+}
+
+func (i *nullableInt) UnmarshalJSON(json []byte) error {
+	s := string(json)
+
+	if s == "null" {
+		i.Init = false
+		return nil
+	}
+
+	v, err := strconv.ParseUint(s, 10, 64)
+
+	i.Val = int(v)
+
+	return err
+}
diff --git a/utils/json/option/string.go b/utils/json/option/string.go
index 74ca0c6..44a942e 100644
--- a/utils/json/option/string.go
+++ b/utils/json/option/string.go
@@ -1,10 +1,51 @@
 package option
 
+import (
+	"encoding/json"
+)
+
+// ================================ String ================================
+
 // String is the option type for strings.
 type String *string
 
-// EmptyString is a zero-length string.
-var EmptyString = NewString("")
-
 // NewString creates a new String with the value of the passed string.
 func NewString(s string) String { return &s }
+
+// ================================ NullableString ================================
+
+// NullableString is a nullable version of a string.
+type NullableString = *nullableString
+
+type nullableString struct {
+	Val  string
+	Init bool
+}
+
+// NullBool serializes to JSON null.
+var NullString = &nullableString{}
+
+// NewNullableString creates a new non-null NullableString with the value of the passed string.
+func NewNullableString(v string) NullableString {
+	return &nullableString{
+		Val:  v,
+		Init: true,
+	}
+}
+
+func (s nullableString) MarshalJSON() ([]byte, error) {
+	if !s.Init {
+		return []byte("null"), nil
+	}
+
+	return []byte("\"" + s.Val + "\""), nil
+}
+
+func (s *nullableString) UnmarshalJSON(b []byte) error {
+	if string(b) == "null" {
+		s.Init = false
+		return nil
+	}
+
+	return json.Unmarshal(b, &s.Val)
+}