Update unit tests adding tests for random access

tests/test.py

@@ -4,10 +4,11 @@
 import stat
 import unittest
 from tempfile import mkdtemp
+from fuse import FuseOSError
 from globaleaks_eph_fs import EphemeralFile, EphemeralOperations
 
-TEST_PATH='TESTFILE.TXT'
-TEST_DATA=b'TEST'
+TEST_PATH = 'TESTFILE.TXT'
+TEST_DATA = b"Hello, world! This is a test data for writing, seeking and reading operations."
 
 
 class TestEphemeralFile(unittest.TestCase):
@@ -26,20 +27,29 @@ def test_create_and_write_file(self):
 
     def test_encryption_and_decryption(self):
         with self.ephemeral_file.open('w') as file:
-            for _ in range(10):
-                file.write(TEST_DATA)
+            file.write(TEST_DATA)
 
-        with self.ephemeral_file.open('r') as file:
-            decrypted_data = file.read()
+        # Define test cases: each case is a tuple (seek_position, read_size, expected_data)
+        seek_tests = [
+            (0, 1, TEST_DATA[:1]),  # Seek at the start read 1 byte
+            (5, 5, TEST_DATA[5:10]),  # Seek forward, read 5 bytes
+            (10, 2, TEST_DATA[10:12]),  # Seek forward, read 2 bytes
+            (0, 3, TEST_DATA[:3]),  # Seek backward, read 3 bytes
+        ]
 
-        self.assertEqual(decrypted_data, TEST_DATA * 10)
+        # Test forward and backward seeking with different offsets
+        with self.ephemeral_file.open('r') as file:
+            for seek_pos, read_size, expected in seek_tests:
+                file.seek(seek_pos)  # Seek to the given position
+                self.assertEqual(file.tell(), seek_pos)  # Check position after seeking forward
+                read_data = file.read(read_size)  # Read the specified number of bytes
+                self.assertEqual(read_data, expected)  # Verify the data matches the expected value
 
     def test_file_cleanup(self):
         file_path = self.ephemeral_file.filepath
         del self.ephemeral_file
         self.assertFalse(os.path.exists(file_path))
 
-
 class TestEphemeralOperations(unittest.TestCase):
     def setUp(self):
         self.storage_dir = mkdtemp()
@@ -89,7 +99,7 @@ def test_unlink_file(self):
         self.assertNotIn(TEST_PATH, self.operations.files)
 
     def test_file_not_found(self):
-        with self.assertRaises(OSError) as context:
+        with self.assertRaises(FuseOSError) as context:
             self.operations.open('/nonexistentfile', os.O_RDONLY)
         self.assertEqual(context.exception.errno, errno.ENOENT)
 
@@ -116,7 +126,7 @@ def test_getattr_file(self):
         # Check times (just ensure they exist)
         self.assertIn('st_atime', attr)
         self.assertIn('st_mtime', attr)
-        self.assertIn('st_ctyme', attr)
+        self.assertIn('st_ctime', attr)
 
     def test_getattr_nonexistent(self):
         """Test getattr on a nonexistent path."""