test: ✅ add unit tests for getLockedUntil with negative timeout

Cover zero, negative (-60 sentinel), zero timestamp, and positive timeout
cases for getLockedUntil().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: James Manuel <moodyjmz@users.noreply.github.com>

Author: moodyjmz

app/src/test/java/com/nextcloud/ui/fileactions/FileActionsViewModelTest.kt

@@ -0,0 +1,71 @@
+/*
+ * Nextcloud - Android Client
+ *
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later OR GPL-2.0-only
+ */
+package com.nextcloud.ui.fileactions
+
+import com.nextcloud.client.account.CurrentAccountProvider
+import com.nextcloud.client.logger.Logger
+import com.nextcloud.utils.TimeConstants
+import com.owncloud.android.datamodel.OCFile
+import com.owncloud.android.files.FileMenuFilter
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Before
+import org.junit.Test
+import org.mockito.kotlin.mock
+
+class FileActionsViewModelTest {
+
+    private lateinit var viewModel: FileActionsViewModel
+
+    @Before
+    fun setUp() {
+        viewModel = FileActionsViewModel(
+            mock<CurrentAccountProvider>(),
+            mock<FileMenuFilter.Factory>(),
+            mock<Logger>()
+        )
+    }
+
+    @Test
+    fun `getLockedUntil returns null when lockTimestamp is zero`() {
+        val file = OCFile("/test.docx").apply {
+            lockTimestamp = 0L
+            lockTimeout = 300L
+        }
+        assertNull(viewModel.getLockedUntil(file))
+    }
+
+    @Test
+    fun `getLockedUntil returns null when lockTimeout is zero`() {
+        val file = OCFile("/test.docx").apply {
+            lockTimestamp = 1_700_000_000L
+            lockTimeout = 0L
+        }
+        assertNull(viewModel.getLockedUntil(file))
+    }
+
+    @Test
+    fun `getLockedUntil returns null when lockTimeout is negative (ETA_INFINITE sentinel)`() {
+        val file = OCFile("/test.docx").apply {
+            lockTimestamp = 1_700_000_000L
+            lockTimeout = -60L
+        }
+        assertNull(viewModel.getLockedUntil(file))
+    }
+
+    @Test
+    fun `getLockedUntil returns correct millis when both values are positive`() {
+        val timestamp = 1_700_000_000L
+        val timeout = 300L
+        val file = OCFile("/test.docx").apply {
+            lockTimestamp = timestamp
+            lockTimeout = timeout
+        }
+        val expected = (timestamp + timeout) * TimeConstants.MILLIS_PER_SECOND
+        assertEquals(expected, viewModel.getLockedUntil(file))
+    }
+}