Add support for specific toasts when backup restoration cannot proceed.

Fixes #10918

app/src/test/java/org/thoughtcrime/securesms/util/BackupUtilTest.kt

@@ -0,0 +1,84 @@
+package org.thoughtcrime.securesms.util
+
+import androidx.documentfile.provider.DocumentFile
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.fail
+import org.junit.BeforeClass
+import org.junit.Test
+import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.mock
+import org.signal.core.util.logging.Log
+import org.thoughtcrime.securesms.testutil.EmptyLogger
+
+class BackupUtilTest {
+
+  companion object {
+    private const val TEST_NAME = "1920837192.backup"
+
+    @BeforeClass
+    @JvmStatic
+    fun setUpClass() {
+      Log.initialize(EmptyLogger())
+    }
+  }
+
+  private val documentFile = mock(DocumentFile::class.java)
+
+  @Test
+  fun `Given a non-existent uri, when I getBackupInfoFromSingleDocumentFile, then I expect NOT_FOUND`() {
+    try {
+      BackupUtil.getBackupInfoFromSingleDocumentFile(documentFile)
+      fail("Expected a BackupFileException")
+    } catch (e: BackupUtil.BackupFileException) {
+      assertEquals(BackupUtil.BackupFileState.NOT_FOUND, e.state)
+    }
+  }
+
+  @Test
+  fun `Given an existent but unreadable uri, when I getBackupInfoFromSingleDocumentFile, then I expect NOT_READABLE`() {
+    givenFileExists()
+
+    try {
+      BackupUtil.getBackupInfoFromSingleDocumentFile(documentFile)
+      fail("Expected a BackupFileException")
+    } catch (e: BackupUtil.BackupFileException) {
+      assertEquals(BackupUtil.BackupFileState.NOT_READABLE, e.state)
+    }
+  }
+
+  @Test
+  fun `Given an existent readable uri with a bad extension, when I getBackupInfoFromSingleDocumentFile, then I expect UNSUPPORTED_FILE_EXTENSION`() {
+    givenFileExists()
+    givenFileIsReadable()
+
+    try {
+      BackupUtil.getBackupInfoFromSingleDocumentFile(documentFile)
+      fail("Expected a BackupFileException")
+    } catch (e: BackupUtil.BackupFileException) {
+      assertEquals(BackupUtil.BackupFileState.UNSUPPORTED_FILE_EXTENSION, e.state)
+    }
+  }
+
+  @Test
+  fun `Given an existent readable uri, when I getBackupInfoFromSingleDocumentFile, then I expect an info`() {
+    givenFileExists()
+    givenFileIsReadable()
+    givenFileHasCorrectExtension()
+
+    val info = BackupUtil.getBackupInfoFromSingleDocumentFile(documentFile)
+    assertNotNull(info)
+  }
+
+  private fun givenFileExists() {
+    doReturn(true).`when`(documentFile).exists()
+  }
+
+  private fun givenFileIsReadable() {
+    doReturn(true).`when`(documentFile).canRead()
+  }
+
+  private fun givenFileHasCorrectExtension() {
+    doReturn(TEST_NAME).`when`(documentFile).name
+  }
+}