From bd4608b467c5be01d4e0cc64923a032a7d2dd8c5 Mon Sep 17 00:00:00 2001
From: tom twinkle <tomtinkle29@gmail.com>
Date: Thu, 25 Aug 2022 11:39:53 +0900
Subject: [PATCH 1/2] feat: add ulid utils

---
 ulid/go.mod       |  5 ++++
 ulid/go.sum       |  3 ++
 ulid/ulid.go      | 70 +++++++++++++++++++++++++++++++++++++++++++++++
 ulid/ulid_test.go | 62 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 140 insertions(+)
 create mode 100644 ulid/go.mod
 create mode 100644 ulid/go.sum
 create mode 100644 ulid/ulid.go
 create mode 100644 ulid/ulid_test.go

diff --git a/ulid/go.mod b/ulid/go.mod
new file mode 100644
index 0000000..6cc3639
--- /dev/null
+++ b/ulid/go.mod
@@ -0,0 +1,5 @@
+module github.com/88labs/go-utils/ulid
+
+go 1.18
+
+require github.com/oklog/ulid/v2 v2.1.0
diff --git a/ulid/go.sum b/ulid/go.sum
new file mode 100644
index 0000000..5a427a4
--- /dev/null
+++ b/ulid/go.sum
@@ -0,0 +1,3 @@
+github.com/oklog/ulid/v2 v2.1.0 h1:+9lhoxAP56we25tyYETBBY1YLA2SaoLvUFgrP2miPJU=
+github.com/oklog/ulid/v2 v2.1.0/go.mod h1:rcEKHmBBKfef9DhnvX7y1HZBYxjXb0cP5ExxNsTT1QQ=
+github.com/pborman/getopt v0.0.0-20170112200414-7148bc3a4c30/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=
diff --git a/ulid/ulid.go b/ulid/ulid.go
new file mode 100644
index 0000000..296e545
--- /dev/null
+++ b/ulid/ulid.go
@@ -0,0 +1,70 @@
+package ulid
+
+import (
+	"crypto/rand"
+	"errors"
+	"io"
+	"sync"
+
+	oklogulid "github.com/oklog/ulid/v2"
+)
+
+type ULID oklogulid.ULID
+
+var (
+	pool = sync.Pool{
+		New: func() interface{} { return oklogulid.Monotonic(rand.Reader, 0) },
+	}
+	zeroValueULID oklogulid.ULID
+	ErrULIDZero   = errors.New("ulid is zero")
+)
+
+func New() (ULID, error) {
+	var entropy = rand.Reader
+	if e, ok := pool.Get().(io.Reader); ok {
+		entropy = e
+		defer pool.Put(e)
+	}
+	id, err := oklogulid.New(oklogulid.Now(), entropy)
+	if err != nil {
+		return ULID{}, err
+	}
+	return ULID(id), nil
+}
+
+func MustNew() ULID {
+	id, err := New()
+	if err != nil {
+		panic(err)
+	}
+	return id
+}
+
+func MustParse(s string) ULID {
+	u := ULID(oklogulid.MustParseStrict(s))
+	if u.IsZero() {
+		panic(ErrULIDZero)
+	}
+	return u
+}
+
+func Parse(s string) (ULID, error) {
+	oklogULID, err := oklogulid.ParseStrict(s)
+	u := ULID(oklogULID)
+	if err != nil {
+		return u, err
+	}
+	if u.IsZero() {
+		return u, ErrULIDZero
+	}
+
+	return u, nil
+}
+
+func (u ULID) ToString() string {
+	return oklogulid.ULID(u).String()
+}
+
+func (u ULID) IsZero() bool {
+	return oklogulid.ULID(u) == zeroValueULID
+}
diff --git a/ulid/ulid_test.go b/ulid/ulid_test.go
new file mode 100644
index 0000000..c603961
--- /dev/null
+++ b/ulid/ulid_test.go
@@ -0,0 +1,62 @@
+package ulid_test
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/88labs/go-utils/ulid"
+)
+
+func TestParse(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		err   string
+	}{
+		{"zero", "00000000000000000000000000", "ulid is zero"},
+		{"ok", "0000XSNJG0MQJHBF4QX1EFD6Y3", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			id, err := ulid.Parse(tt.input)
+			if len(tt.err) == 0 {
+				if err != nil {
+					t.Fatalf("want no err, but has err %v", err)
+				}
+				if id.IsZero() {
+					t.Fatal("ulid is zero")
+				}
+			}
+
+			if len(tt.err) > 0 {
+				if err == nil {
+					t.Fatalf("want %v, but %v", tt.err, err)
+				}
+				if !strings.Contains(err.Error(), tt.err) {
+					t.Fatalf("want %v, but %v", tt.err, err)
+				}
+			}
+		})
+	}
+}
+
+func TestMustNew(t *testing.T) {
+	t.Run("ulidnew", func(t *testing.T) {
+		var wg sync.WaitGroup
+		num := 100000
+		wg.Add(num)
+		for i := 0; i < num; i++ {
+			go func() {
+				defer wg.Done()
+				id := ulid.MustNew()
+				if id.IsZero() {
+					panic(fmt.Sprintf("zero: %v", id))
+				}
+			}()
+		}
+		wg.Wait()
+	})
+}

From a6dfd98aab3dcd35c8d320525842869fb0a34da6 Mon Sep 17 00:00:00 2001
From: tom twinkle <tomtinkle29@gmail.com>
Date: Thu, 25 Aug 2022 12:10:43 +0900
Subject: [PATCH 2/2] Changed function name to satisfy Stringers interface

---
 ulid/ulid.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ulid/ulid.go b/ulid/ulid.go
index 296e545..fde6ef1 100644
--- a/ulid/ulid.go
+++ b/ulid/ulid.go
@@ -61,7 +61,7 @@ func Parse(s string) (ULID, error) {
 	return u, nil
 }
 
-func (u ULID) ToString() string {
+func (u ULID) String() string {
 	return oklogulid.ULID(u).String()
 }