Merge main into fix-148-async-seen-flag

app/src/test/kotlin/org/libremail/push/BatteryOptimizationManagerTest.kt

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+package org.libremail.push
+
+import org.junit.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+/**
+ * Unit tests for the `firstResolvableOrElseLast` fallback-selection helper that backs
+ * [BatteryOptimizationManager.settingsIntent] (#150). Deliberately exercised with plain `String`
+ * candidates rather than real `Intent`s: `Intent`/`Uri`/`PackageManager` are unmocked Android SDK stubs
+ * in a JVM unit test and throw on use, so the selection/ordering logic is kept generic and Android-free
+ * specifically so it's testable here (see its KDoc). The real candidate intents and end-to-end
+ * resolution are covered by the instrumented `BatteryOptimizationStepTest`.
+ */
+class BatteryOptimizationManagerTest {
+
+    @Test
+    fun `returns the first candidate that resolves`() {
+        assertEquals("b", firstResolvableOrElseLast(listOf("a", "b", "c")) { it == "b" })
+    }
+
+    @Test
+    fun `returns the only candidate when it is the first checked, even if it would not resolve`() {
+        assertEquals("only", firstResolvableOrElseLast(listOf("only")) { it == "only" })
+    }
+
+    @Test
+    fun `falls back to the last candidate when none resolve, rather than dead-ending`() {
+        assertEquals("c", firstResolvableOrElseLast(listOf("a", "b", "c")) { false })
+    }
+
+    @Test
+    fun `falls back to the last candidate even when it is the only one and it does not resolve`() {
+        assertEquals("only", firstResolvableOrElseLast(listOf("only")) { false })
+    }
+
+    @Test
+    fun `prefers an earlier resolving candidate over a later one, even if both resolve`() {
+        assertEquals("first", firstResolvableOrElseLast(listOf("first", "second")) { true })
+    }
+
+    @Test
+    fun `rejects an empty candidate list rather than silently returning nothing`() {
+        assertFailsWith<IllegalArgumentException> {
+            firstResolvableOrElseLast(emptyList<String>()) { true }
+        }
+    }
+}