feat(subbanner): 서브 배너 도메인과 링크 불변식을 추가한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/subbanner/domain/SubBanner.kt

@@ -0,0 +1,20 @@
+package kr.co.vividnext.sodalive.v2.subbanner.domain
+
+import java.time.LocalDateTime
+
+data class SubBanner(
+    val id: Long? = null,
+    val placement: SubBannerPlacement,
+    val imagePath: String,
+    val webUrl: String?,
+    val androidDeepLink: String?,
+    val iosDeepLink: String?,
+    val startDate: LocalDateTime?,
+    val endDate: LocalDateTime?
+) {
+    init {
+        require(!webUrl.isNullOrBlank() || !androidDeepLink.isNullOrBlank() || !iosDeepLink.isNullOrBlank()) {
+            "At least one link must be nonblank"
+        }
+    }
+}

src/main/kotlin/kr/co/vividnext/sodalive/v2/subbanner/domain/SubBannerPlacement.kt

@@ -0,0 +1,6 @@
+package kr.co.vividnext.sodalive.v2.subbanner.domain
+
+enum class SubBannerPlacement {
+    HOME_RECOMMENDATION,
+    CONTENT_RECOMMENDATION
+}

src/test/kotlin/kr/co/vividnext/sodalive/v2/subbanner/domain/SubBannerTest.kt

@@ -0,0 +1,53 @@
+package kr.co.vividnext.sodalive.v2.subbanner.domain
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertThrows
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+
+class SubBannerTest {
+    @Test
+    @DisplayName("세 링크 중 하나 이상이 있는 7개 조합은 허용하고 모두 null이면 거부한다")
+    fun shouldRejectAllEmptyLinksAndAllowSevenNonEmptyCombinations() {
+        for (mask in 1..7) {
+            val webUrl = if (mask and 1 != 0) "https://example.com/banner?next=%2Fhome" else null
+            val androidDeepLink = if (mask and 2 != 0) "sodalive://content/123?from=banner" else null
+            val iosDeepLink = if (mask and 4 != 0) "sodalive-ios://content/123#detail" else null
+
+            val banner = banner(webUrl, androidDeepLink, iosDeepLink)
+
+            assertEquals(webUrl, banner.webUrl)
+            assertEquals(androidDeepLink, banner.androidDeepLink)
+            assertEquals(iosDeepLink, banner.iosDeepLink)
+        }
+
+        assertThrows(IllegalArgumentException::class.java) { banner(null, null, null) }
+    }
+
+    @Test
+    @DisplayName("null과 빈 문자열 및 공백만으로 된 모든 조합을 거부한다")
+    fun shouldRejectAllBlankLinksAndAllowAnyNonblankLink() {
+        val emptyLinks = listOf(null, "", " ", "\t\n")
+        for (webUrl in emptyLinks) {
+            for (androidDeepLink in emptyLinks) {
+                for (iosDeepLink in emptyLinks) {
+                    assertThrows(IllegalArgumentException::class.java) { banner(webUrl, androidDeepLink, iosDeepLink) }
+                }
+            }
+        }
+
+        assertEquals("https://example.com", banner("https://example.com", " ", "").webUrl)
+        assertEquals("sodalive://home", banner(" ", "sodalive://home", "").androidDeepLink)
+        assertEquals("sodalive-ios://home", banner("", " ", "sodalive-ios://home").iosDeepLink)
+    }
+
+    private fun banner(webUrl: String?, androidDeepLink: String?, iosDeepLink: String?): SubBanner = SubBanner(
+        placement = SubBannerPlacement.HOME_RECOMMENDATION,
+        imagePath = "sub-banner/image.png",
+        webUrl = webUrl,
+        androidDeepLink = androidDeepLink,
+        iosDeepLink = iosDeepLink,
+        startDate = null,
+        endDate = null
+    )
+}