feat: 내 그룹 조회

src/main/kotlin/com/hero/alignlab/domain/group/application/MyGroupService.kt

@@ -0,0 +1,18 @@
+package com.hero.alignlab.domain.group.application
+
+import com.hero.alignlab.domain.auth.model.AuthUser
+import com.hero.alignlab.domain.group.model.response.MyGroupResponse
+import org.springframework.stereotype.Service
+
+@Service
+class MyGroupService(
+    private val groupService: GroupService,
+    private val groupUserService: GroupUserService,
+) {
+    suspend fun getMyGroup(user: AuthUser): MyGroupResponse? {
+        val groupUser = groupUserService.findByUid(user.uid) ?: return null
+        val group = groupService.findByIdOrThrow(groupUser.groupId)
+
+        return MyGroupResponse.from(group)
+    }
+}

src/main/kotlin/com/hero/alignlab/domain/group/model/response/MyGroupResponse.kt

@@ -0,0 +1,19 @@
+package com.hero.alignlab.domain.group.model.response
+
+import com.hero.alignlab.domain.group.domain.Group
+
+data class MyGroupResponse(
+    val id: Long,
+    val name: String,
+    val description: String?,
+) {
+    companion object {
+        fun from(group: Group): MyGroupResponse {
+            return MyGroupResponse(
+                id = group.id,
+                name = group.name,
+                description = group.description
+            )
+        }
+    }
+}

src/main/kotlin/com/hero/alignlab/domain/group/resource/MyGroupResource.kt

@@ -0,0 +1,25 @@
+package com.hero.alignlab.domain.group.resource
+
+import com.hero.alignlab.common.extension.wrapOk
+import com.hero.alignlab.domain.auth.model.AuthUser
+import com.hero.alignlab.domain.group.application.MyGroupService
+import io.swagger.v3.oas.annotations.Operation
+import io.swagger.v3.oas.annotations.tags.Tag
+import org.springframework.http.MediaType
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+
+@Tag(name = "My Group API")
+@RestController
+@RequestMapping(produces = [MediaType.APPLICATION_JSON_VALUE])
+class MyGroupResource(
+    private val myGroupService: MyGroupService,
+) {
+    /** 그룹이 없는 경우,  noContent로 반환 */
+    @Operation(summary = "마이 그룹 조회")
+    @GetMapping("/api/v1/groups/my-group")
+    suspend fun getMyGroup(
+        user: AuthUser
+    ) = myGroupService.getMyGroup(user).wrapOk()
+}