diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b12812..6555105 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,7 +32,7 @@ add_executable(client ${CLIENT_SRCS} ${SHARED_SRCS})
 target_include_directories(client PRIVATE src/shared src/server src/client)
 target_link_libraries(client PRIVATE Threads::Threads ${ZSTD_LIBRARY})
 
-add_executable(tests ${TEST_SRCS} ${SHARED_SRCS})
+add_executable(tests ${TEST_SRCS} ${SHARED_SRCS} src/client/scanner.c)
 target_include_directories(tests PRIVATE tests src/shared src/server src/client)
 target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY})
 
diff --git a/src/shared/chunk.c b/src/shared/chunk.c
index 9bdb0c1..87d5f1e 100644
--- a/src/shared/chunk.c
+++ b/src/shared/chunk.c
@@ -131,7 +131,9 @@ Data *chunk_compress(Chunk *chunk, int compression_level) {
   }
 
   log_message(LOG_LEVEL_DEBUG, "Chunk succesfully compressed");
-  return data_compress(data, compression_level);
+  Data *compressed = data_compress(data, compression_level);
+  data_destroy(data);
+  return compressed;
 }
 
 Chunk *chunk_decompress(Data *compressed_data) {
@@ -142,7 +144,7 @@ Chunk *chunk_decompress(Data *compressed_data) {
     return NULL;
   }
   
-  ArrayList *files = array_list_create((void (*)(void *))data_destroy);
+  ArrayList *files = array_list_create(file_destroy);
   char *data_pointer = uncompressed_data->data;
   size_t remaining_size = uncompressed_data->size;
   
@@ -207,7 +209,16 @@ Chunk *chunk_decompress(Data *compressed_data) {
       return NULL;
     }
     
-    file->data = data_create(data_pointer, data_size);
+    void *file_data = malloc(data_size);
+    if (file_data == NULL) {
+      perror("Could not allocate memory for file data");
+      free(path);
+      array_list_delete(files);
+      data_destroy(uncompressed_data);
+      return NULL;
+    }
+    memcpy(file_data, data_pointer, data_size);
+    file->data = data_create(file_data, data_size);
     data_pointer += data_size;
     remaining_size -= data_size;
     
@@ -219,8 +230,9 @@ Chunk *chunk_decompress(Data *compressed_data) {
   File **file_array = (File **)array_list_to_array(files);
   Chunk *chunk = chunk_create(file_array, files->size);
   
-  // Clean up
+  // Clean up - files are now owned by the chunk
   free(file_array);
+  files->item_destroyer = NULL;
   array_list_delete(files);
   data_destroy(uncompressed_data);
   
diff --git a/src/shared/data.c b/src/shared/data.c
index d77130a..689c4d4 100644
--- a/src/shared/data.c
+++ b/src/shared/data.c
@@ -25,6 +25,7 @@ Data *data_create(void *data, size_t data_size) {
 }
 
 void data_destroy(Data *data) {
+  if (data == NULL) return;
   free(data->data);
   free(data);
 }
diff --git a/tests/runner.c b/tests/runner.c
index 40dd500..b05f007 100644
--- a/tests/runner.c
+++ b/tests/runner.c
@@ -1,7 +1,9 @@
 #include "test_array_list.h"
 #include "test_chunk.h"
+#include "test_compression.h"
 #include "test_config.h"
 #include "test_queue.h"
+#include "test_scanner.h"
 #include "test_shared_utils.h"
 #include "test_utils.h"
 #include <stdio.h>
@@ -19,6 +21,8 @@ int main() {
   RUN_TEST(test_shared_utils);
   RUN_TEST(test_chunk);
   RUN_TEST(test_config);
+  RUN_TEST(test_compression);
+  RUN_TEST(test_scanner);
 
   printf("\n\033[1;36m=== TEST SUMMARY ===\033[0m\n");
   printf("Total Tests Run: %d\n", tests_run);
diff --git a/tests/test_compression.c b/tests/test_compression.c
new file mode 100644
index 0000000..4542b79
--- /dev/null
+++ b/tests/test_compression.c
@@ -0,0 +1,110 @@
+#include "test_utils.h"
+#include "chunk.h"
+#include "data.h"
+#include "file.h"
+#include "utils.h"
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static void test_data_compress_decompress_roundtrip() {
+  char original[] = "Hello, World! This is test data for compression round-trip!";
+  size_t len = strlen(original);
+
+  char *buf = malloc(len);
+  memcpy(buf, original, len);
+  Data *original_data = data_create(buf, len);
+  EXPECT_NOT_NULL(original_data);
+
+  Data *compressed = data_compress(original_data, 3);
+  EXPECT_NOT_NULL(compressed);
+
+  Data *decompressed = data_decompress(compressed);
+  EXPECT_NOT_NULL(decompressed);
+  EXPECT_EQ_INT((int)decompressed->size, (int)len);
+  EXPECT_EQ_INT(memcmp(decompressed->data, original, len), 0);
+
+  data_destroy(original_data);
+  data_destroy(compressed);
+  data_destroy(decompressed);
+}
+
+static void test_data_compress_decompress_large() {
+  size_t size = 1024 * 10;
+  char *original = malloc(size);
+  EXPECT_NOT_NULL(original);
+  for (size_t i = 0; i < size; i++)
+    original[i] = (char)(i % 256);
+
+  Data *original_data = data_create(original, size);
+  EXPECT_NOT_NULL(original_data);
+
+  Data *compressed = data_compress(original_data, 1);
+  EXPECT_NOT_NULL(compressed);
+
+  Data *decompressed = data_decompress(compressed);
+  EXPECT_NOT_NULL(decompressed);
+  EXPECT_EQ_INT((int)decompressed->size, (int)size);
+  EXPECT_EQ_INT(memcmp(decompressed->data, original, size), 0);
+
+  data_destroy(original_data);
+  data_destroy(compressed);
+  data_destroy(decompressed);
+}
+
+static void test_chunk_compress_decompress_roundtrip() {
+  char *path1 = "temp_comp_test_1.txt";
+  char *content1 = "chunk compression test file 1";
+  unsigned long long len1 = strlen(content1);
+
+  char *path2 = "temp_comp_test_2.txt";
+  char *content2 = "chunk compression test file 2 with more data";
+  unsigned long long len2 = strlen(content2);
+
+  to_disk(path1, content1, len1);
+  to_disk(path2, content2, len2);
+
+  struct stat st1, st2;
+  EXPECT_EQ_INT(stat(path1, &st1), 0);
+  EXPECT_EQ_INT(stat(path2, &st2), 0);
+
+  File *f1 = file_create(path1, &st1);
+  File *f2 = file_create(path2, &st2);
+  EXPECT_NOT_NULL(f1);
+  EXPECT_NOT_NULL(f2);
+
+  file_load_data(f1);
+  file_load_data(f2);
+
+  File *files[2] = {f1, f2};
+  Chunk *chunk = chunk_create(files, 2);
+  EXPECT_NOT_NULL(chunk);
+
+  Data *compressed = chunk_compress(chunk, 3);
+  EXPECT_NOT_NULL(compressed);
+
+  Chunk *decompressed_chunk = chunk_decompress(compressed);
+  EXPECT_NOT_NULL(decompressed_chunk);
+  EXPECT_EQ_INT(decompressed_chunk->element_count, 2);
+
+  EXPECT_EQ_STR(decompressed_chunk->items[0]->path, path1);
+  EXPECT_EQ_INT((int)decompressed_chunk->items[0]->data->size, (int)len1);
+  EXPECT_EQ_INT(memcmp(decompressed_chunk->items[0]->data->data, content1, len1), 0);
+
+  EXPECT_EQ_STR(decompressed_chunk->items[1]->path, path2);
+  EXPECT_EQ_INT((int)decompressed_chunk->items[1]->data->size, (int)len2);
+  EXPECT_EQ_INT(memcmp(decompressed_chunk->items[1]->data->data, content2, len2), 0);
+
+  chunk_destroy(chunk);
+  data_destroy(compressed);
+  chunk_destroy(decompressed_chunk);
+
+  unlink(path1);
+  unlink(path2);
+}
+
+void test_compression() {
+  test_data_compress_decompress_roundtrip();
+  test_data_compress_decompress_large();
+  test_chunk_compress_decompress_roundtrip();
+}
diff --git a/tests/test_compression.h b/tests/test_compression.h
new file mode 100644
index 0000000..d86ff93
--- /dev/null
+++ b/tests/test_compression.h
@@ -0,0 +1,6 @@
+#ifndef TEST_COMPRESSION_H
+#define TEST_COMPRESSION_H
+
+void test_compression();
+
+#endif
diff --git a/tests/test_scanner.c b/tests/test_scanner.c
new file mode 100644
index 0000000..4446333
--- /dev/null
+++ b/tests/test_scanner.c
@@ -0,0 +1,124 @@
+#include "test_utils.h"
+#include "scanner.h"
+#include "file.h"
+#include "utils.h"
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static void create_test_file(const char *path, const char *content) {
+  to_disk(path, content, strlen(content));
+}
+
+static void test_scanner_single_file() {
+  const char *dir = "test_scan_dir_single";
+  const char *file1 = "test_scan_dir_single/file1.txt";
+  const char *content1 = "hello scanner";
+
+  mkdir(dir, 0755);
+  create_test_file(file1, content1);
+
+  DirectoryScanner *scanner = directory_scanner_create((char *)dir);
+  EXPECT_NOT_NULL(scanner);
+
+  Chunk *chunk = directory_scanner_next(scanner);
+  EXPECT_NOT_NULL(chunk);
+  EXPECT_EQ_INT(chunk->element_count, 1);
+  EXPECT_EQ_STR(chunk->items[0]->path, file1);
+
+  Chunk *next = directory_scanner_next(scanner);
+  EXPECT_NULL(next);
+
+  chunk_destroy(chunk);
+  directory_scanner_destroy(scanner);
+  unlink(file1);
+  rmdir(dir);
+}
+
+static void test_scanner_multiple_files() {
+  const char *dir = "test_scan_dir_multi";
+  const char *file1 = "test_scan_dir_multi/a.txt";
+  const char *file2 = "test_scan_dir_multi/b.txt";
+  const char *content1 = "alpha";
+  const char *content2 = "beta";
+
+  mkdir(dir, 0755);
+  create_test_file(file1, content1);
+  create_test_file(file2, content2);
+
+  DirectoryScanner *scanner = directory_scanner_create((char *)dir);
+  EXPECT_NOT_NULL(scanner);
+
+  Chunk *chunk = directory_scanner_next(scanner);
+  EXPECT_NOT_NULL(chunk);
+  EXPECT_EQ_INT(chunk->element_count, 2);
+
+  int found1 = 0, found2 = 0;
+  for (int i = 0; i < chunk->element_count; i++) {
+    if (strcmp(chunk->items[i]->path, file1) == 0) found1 = 1;
+    if (strcmp(chunk->items[i]->path, file2) == 0) found2 = 1;
+  }
+  EXPECT_TRUE(found1);
+  EXPECT_TRUE(found2);
+
+  Chunk *next = directory_scanner_next(scanner);
+  EXPECT_NULL(next);
+
+  chunk_destroy(chunk);
+  directory_scanner_destroy(scanner);
+  unlink(file1);
+  unlink(file2);
+  rmdir(dir);
+}
+
+static void test_scanner_subdirectory() {
+  const char *root = "test_scan_sub";
+  const char *sub = "test_scan_sub/sub";
+  const char *root_file = "test_scan_sub/root.txt";
+  const char *sub_file = "test_scan_sub/sub/sub_file.txt";
+  const char *content = "nested content";
+
+  mkdir(root, 0755);
+  mkdir(sub, 0755);
+  create_test_file(root_file, content);
+  create_test_file(sub_file, content);
+
+  DirectoryScanner *scanner = directory_scanner_create((char *)root);
+  EXPECT_NOT_NULL(scanner);
+
+  int total_files = 0;
+  Chunk *chunk;
+  while ((chunk = directory_scanner_next(scanner)) != NULL) {
+    total_files += chunk->element_count;
+    chunk_destroy(chunk);
+  }
+  EXPECT_EQ_INT(total_files, 2);
+
+  directory_scanner_destroy(scanner);
+  unlink(root_file);
+  unlink(sub_file);
+  rmdir(sub);
+  rmdir(root);
+}
+
+static void test_scanner_empty_directory() {
+  const char *dir = "test_scan_empty";
+
+  mkdir(dir, 0755);
+
+  DirectoryScanner *scanner = directory_scanner_create((char *)dir);
+  EXPECT_NOT_NULL(scanner);
+
+  Chunk *chunk = directory_scanner_next(scanner);
+  EXPECT_NULL(chunk);
+
+  directory_scanner_destroy(scanner);
+  rmdir(dir);
+}
+
+void test_scanner() {
+  test_scanner_single_file();
+  test_scanner_multiple_files();
+  test_scanner_subdirectory();
+  test_scanner_empty_directory();
+}
diff --git a/tests/test_scanner.h b/tests/test_scanner.h
new file mode 100644
index 0000000..a8c6276
--- /dev/null
+++ b/tests/test_scanner.h
@@ -0,0 +1,6 @@
+#ifndef TEST_SCANNER_H
+#define TEST_SCANNER_H
+
+void test_scanner();
+
+#endif