Bug/#21 사용자 랜덤 선택 기능 오류 (#22)

* fix: prevent `PickRandomNumber` panic when `upperBound` is 1

- Add a test case for `PickRandomNumber` to cover edge cases.

* chore: add log for channel member count validation

* chore: add discord intents options

Author: tidavid1

cmd/main.go

@@ -32,7 +32,7 @@ func main() {
 		log.Fatal("error creating Discord session,", err)
 	}
 
-	discord.Identify.Intents = discordgo.IntentsGuildMessages | discordgo.IntentsGuildMessageReactions | discordgo.IntentsGuilds
+	discord.Identify.Intents = discordgo.IntentsGuildMessages | discordgo.IntentsGuildMessageReactions | discordgo.IntentsGuilds | discordgo.IntentsGuildVoiceStates | discordgo.IntentsGuildMembers
 
 	discord.AddHandler(handler.EasterEggHandler)
 	discord.AddHandler(handler.RegisterCommands)

internal/handler/handlers.go

@@ -194,7 +194,6 @@ func getRandomUserByChannel(session *discordgo.Session, interaction *discordgo.I
 		sendMessage(session, interaction, "음성 채널에서만 사용할 수 있는 명령어입니다.")
 		return
 	}
-	log.Printf("Channel type: %v", channel.Type)
 	guild, err := session.State.Guild(channel.GuildID)
 	// 서버 정보를 불러오는 중 오류가 발생하면 에러 메시지를 전송합니다.
 	if err != nil {
@@ -215,6 +214,7 @@ func getRandomUserByChannel(session *discordgo.Session, interaction *discordgo.I
 			}
 		}
 	}
+	log.Printf("Members: %+v", members)
 	// 음성 채널에 사용자가 없으면 에러 메시지를 전송합니다.
 	if len(members) == 0 {
 		sendMessage(session, interaction, "음성 채널에 사용자가 없습니다.")

internal/util/util.go

@@ -64,5 +64,5 @@ func PickRandomNumber(upperBound int) int {
 	}
 	source := rand.NewSource(time.Now().UnixNano())
 	r := rand.New(source)
-	return r.Intn(upperBound - 1)
+	return r.Intn(upperBound)
 }

internal/util/util_test.go

@@ -2,6 +2,7 @@ package util
 
 import (
 	"os"
+	"strconv"
 	"testing"
 	"time"
 )
@@ -109,13 +110,30 @@ func TestLoadFile_InvalidFile(t *testing.T) {
 	}
 }
 
-func TestPickRandomNumber(t *testing.T) {
-	// Arrange
-	upperBound := 10
-	// Act
-	actual := PickRandomNumber(upperBound)
-	// Assert
-	if actual < 0 || actual >= upperBound {
-		t.Errorf("expected 0 <= actual < %d, but got %d", upperBound, actual)
+func TestPickRandomNumber_ValidInput(t *testing.T) {
+	testCases := []int{1, 10, 100, 1000, 10000}
+	for _, tc := range testCases {
+		t.Run("UpperBound: "+strconv.Itoa(tc), func(t *testing.T) {
+			// Act
+			actual := PickRandomNumber(tc)
+			// Assert
+			if actual < 0 || actual >= tc {
+				t.Errorf("expected 0 <= actual < %d, but got %d", tc, actual)
+			}
+		})
+	}
+}
+
+func TestPickRandomNumber_InputLessThenOrEqualZero(t *testing.T) {
+	testCases := []int{0, -1, -10, -100, -1000}
+	for _, tc := range testCases {
+		t.Run("UpperBound: "+strconv.Itoa(tc), func(t *testing.T) {
+			// Act
+			actual := PickRandomNumber(tc)
+			// Assert
+			if actual != 0 {
+				t.Errorf("expected 0, but got %d", actual)
+			}
+		})
 	}
 }