diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 0000000..8f6a246
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,2 @@
+[run]
+source=p2pfs
diff --git a/setup.py b/setup.py
index 2f65897..2ad9607 100644
--- a/setup.py
+++ b/setup.py
@@ -28,6 +28,9 @@ setup(
     keywords='P2P, Networking',
     packages=find_packages(exclude=['tests']),
     install_requires=['pybase64', 'zstandard', 'coloredlogs', 'tabulate'],
+    extras_require={
+        'test': ['pytest-cov', 'pytest', 'coverage'],
+    },
     entry_points={
         'console_scripts': [
             'p2pfs=p2pfs.__main__:main',
diff --git a/tests/test_main.py b/tests/test_main.py
index 7919a3c..8d5f088 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1 +1,58 @@
-from p2pfs
\ No newline at end of file
+import os
+import hashlib
+from p2pfs import Peer, Tracker
+
+
+def fmd5(fname):
+    """ calculate the md5 value of a file
+    :param fname: file name
+    :return: md5 value.
+    """
+    hash_md5 = hashlib.md5()
+    with open(fname, "rb") as f:
+        for chunk in iter(lambda: f.read(4096), b""):
+            hash_md5.update(chunk)
+    return hash_md5.hexdigest()
+
+
+def test_main():
+    peer_1, peer_2 = Peer('localhost', 0, 'localhost', 8880), Peer('localhost', 0, 'localhost', 8880)
+    tracker = Tracker('localhost', 8880)
+    tracker.start()
+    peer_1.start()
+    peer_2.start()
+    
+    with open('test_small_file', 'wb') as fout:
+        fout.write(os.urandom(1000))
+
+    with open('test_big_file', 'wb') as fout:
+        # write 500MB random data into the file
+        for _ in range(500):
+            fout.write(os.urandom(1000 * 1000))
+    # peer1 publish small file and peer2 downloads it
+    peer_1.publish('test_small_file')
+    file_list = tracker.file_list()
+    assert 'test_small_file' in file_list
+    assert file_list['test_small_file']['size'] == 1000
+    file_list = peer_2.list_file()
+    assert 'test_small_file' in file_list
+    result, msg = peer_2.download('test_small_file', 'downloaded_small_file')
+    assert result is True
+    assert os.path.exists('downloaded_small_file')
+    assert fmd5('test_small_file') == fmd5('downloaded_small_file')
+
+    peer_2.publish('test_big_file')
+    file_list = tracker.file_list()
+    assert 'test_big_file' in file_list and 'test_small_file' in file_list
+    assert file_list['test_big_file']['size'] == 500 * 1000 * 1000
+    file_list = peer_1.list_file()
+    assert 'test_big_file' in file_list and 'test_small_file' in file_list
+    result, msg = peer_1.download('test_big_file', 'downloaded_big_file')
+    assert result is True
+    assert os.path.exists('downloaded_big_file')
+    assert fmd5('test_big_file') == fmd5('downloaded_big_file')
+
+    os.remove('test_small_file')
+    os.remove('test_big_file')
+    os.remove('downloaded_small_file')
+    os.remove('downloaded_big_file')