From e495e2d4d0ad20a6f2569d6754c8befc94e74aff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=BA=90=E6=96=87=E9=9B=A8?=
 <41315874+fumiama@users.noreply.github.com>
Date: Fri, 13 Oct 2023 00:45:21 +0900
Subject: [PATCH] add helper.UnderlineToCamel

---
 helper.go      | 19 +++++++++++++++++++
 helper_test.go | 22 ++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 helper_test.go

diff --git a/helper.go b/helper.go
index 7af0020..454f8fa 100644
--- a/helper.go
+++ b/helper.go
@@ -47,3 +47,22 @@ func MessageUnescape(text string) string {
 	text = strings.ReplaceAll(text, "&gt;", ">")
 	return text
 }
+
+// UnderlineToCamel convert abc_def to AbcDef
+func UnderlineToCamel(s string) string {
+	sb := strings.Builder{}
+	isnextupper := true
+	for _, c := range []byte(strings.ToLower(s)) {
+		if c == '_' {
+			isnextupper = true
+			continue
+		}
+		if isnextupper {
+			sb.WriteString(strings.ToUpper(string(c)))
+			isnextupper = false
+			continue
+		}
+		sb.WriteByte(c)
+	}
+	return sb.String()
+}
diff --git a/helper_test.go b/helper_test.go
new file mode 100644
index 0000000..720ae80
--- /dev/null
+++ b/helper_test.go
@@ -0,0 +1,22 @@
+package nano
+
+import "testing"
+
+func TestUnderlineToCamel(t *testing.T) {
+	x := UnderlineToCamel("GUILD_CREATE")
+	if x != "GuildCreate" {
+		t.Fatal("expected GuildCreate but got", x)
+	}
+	x = UnderlineToCamel("GUILD_MEMBER_UPDATE")
+	if x != "GuildMemberUpdate" {
+		t.Fatal("expected GuildMemberUpdate but got", x)
+	}
+	x = UnderlineToCamel("OPEN_FORUM_THREAD_CREATE")
+	if x != "OpenForumThreadCreate" {
+		t.Fatal("expected OpenForumThreadCreate but got", x)
+	}
+	x = UnderlineToCamel("AUDIO_OR_LIVE_CHANNEL_MEMBER_ENTER")
+	if x != "AudioOrLiveChannelMemberEnter" {
+		t.Fatal("expected AudioOrLiveChannelMemberEnter but got", x)
+	}
+}