merge: W52K —— 「后台保持连接」开关 + 前台服务（默认关；开了才有常驻通知）

app/src/test/kotlin/top/yeij/cyrene/ui/settings/KeepAliveSummaryTest.kt

@@ -0,0 +1,61 @@
+package top.yeij.cyrene.ui.settings
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * 开关下面那行字（纯函数）。
+ *
+ * 这一行的价值全在「说真话」，所以钉的也是真话：
+ * 1. **开的代价自己说出来**（常驻通知 + 多耗电）——不说的代价会变成用户某天「莫名多了条通知」的意外；
+ * 2. **跑不了的时候不许说在跑**（通知权限被拒 / 被撤时，一个字都不提「已开」）；
+ * 3. 四个分支互不相同：任何一次改文案都不该把某一档悄悄吞掉。
+ */
+class KeepAliveSummaryTest {
+
+    @Test
+    fun `the off state says what it costs to stay off`() {
+        val text = keepAliveSummary(enabled = false, notificationsAllowed = true, permissionJustDenied = false)
+
+        assertTrue("关着要说清后果（消息不丢但连接会断）：$text", text.contains("消息不会丢"))
+        assertTrue(text.contains("断开"))
+    }
+
+    @Test
+    fun `the on state spells out the price`() {
+        val text = keepAliveSummary(enabled = true, notificationsAllowed = true, permissionJustDenied = false)
+
+        assertTrue("必须明说会常驻一条通知：$text", text.contains("通知"))
+        assertTrue("必须明说会多耗电：$text", text.contains("电"))
+    }
+
+    @Test
+    fun `an enabled switch without the notification permission never claims to be working`() {
+        val text = keepAliveSummary(enabled = true, notificationsAllowed = false, permissionJustDenied = false)
+
+        assertFalse("权限不在，绝不能写成「已开」：$text", text.contains("已开"))
+        assertTrue("要说清为什么不起作用：$text", text.contains("起不来"))
+    }
+
+    @Test
+    fun `a just denied request reports the denial instead of pretending success`() {
+        val text = keepAliveSummary(enabled = false, notificationsAllowed = false, permissionJustDenied = true)
+
+        assertTrue("要说清被拒了：$text", text.contains("拒绝"))
+        assertFalse("被拒时不许写成「已开」：$text", text.contains("已开"))
+    }
+
+    @Test
+    fun `the four states are told apart`() {
+        val texts = listOf(
+            keepAliveSummary(enabled = false, notificationsAllowed = true, permissionJustDenied = false),
+            keepAliveSummary(enabled = true, notificationsAllowed = true, permissionJustDenied = false),
+            keepAliveSummary(enabled = true, notificationsAllowed = false, permissionJustDenied = false),
+            keepAliveSummary(enabled = false, notificationsAllowed = false, permissionJustDenied = true),
+        )
+
+        assertEquals("四个分支必须四句不同的话", 4, texts.toSet().size)
+    }
+}