test: add unit tests

Tests written using unittest [1] and hypothesis [2] modules. We use
hypothesis v4.57.0 because it is a latest version with Python 2.7
support.

How-to run:

$ make test_unittest

Unit test that pass tarantoolctl output to JSON serializer failed [4]
with Python 3.5 because it expects argument with type str while we pass
bytes. Later Python versions (since 3.6, see [5]) starts to accept
bytes and bytearray too. To fix test for Python 3.5 added explicit
conversion of bytes to str before JSON serialization.

======================================================================
ERROR: test_extract_schema_from_snapshot (__main__.TestUtils)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test/unittest/test_lib_utils.py", line 14, in test_extract_schema_from_snapshot
    v = utils.extract_schema_from_snapshot(snapshot_path)
  File "/home/runner/work/test-run/test-run/lib/utils.py", line 309, in extract_schema_from_snapshot
    for row in xlog_rows(snapshot_path):
  File "/home/runner/work/test-run/test-run/lib/utils.py", line 290, in xlog_rows
    yield json.loads(line)
  File "/opt/hostedtoolcache/Python/3.5.10/x64/lib/python3.5/json/__init__.py", line 312, in loads
    s.__class__.__name__))
TypeError: the JSON object must be str, not 'bytes'

1. https://docs.python.org/3/library/unittest.html
2. https://hypothesis.readthedocs.io/en/latest/
3. https://hypothesis.readthedocs.io/en/latest/changes.html#v4-57-0
4. https://github.com/tarantool/test-run/runs/2199956452
5. https://docs.python.org/3/library/json.html#json.loads

Author: ligurio

.gitignore

@@ -41,6 +41,7 @@ htmlcov/
 .coverage
 .coverage.*
 .cache
+.hypothesis/
 nosetests.xml
 coverage.xml
 *,cover

lib/utils.py

@@ -286,8 +286,8 @@ def xlog_rows(xlog_path):
     cmd = ['tarantoolctl', 'cat', xlog_path, '--format=json', '--show-system']
     with open(os.devnull, 'w') as devnull:
         process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=devnull)
-    for line in process.stdout.readlines():
-        yield json.loads(line)
+        for line in process.stdout.readlines():
+            yield json.loads(bytes_to_str(line))
 
 
 def extract_schema_from_snapshot(snapshot_path):

requirements-test.txt

@@ -1 +1,2 @@
 flake8==3.7.9
+hypothesis==4.*

test/unittest/00000000000000000003.snap

@@ -0,0 +1,34 @@
+import unittest
+
+import socket
+
+from hypothesis import given, settings
+from hypothesis.strategies import integers
+
+import lib.utils as utils
+
+
+class TestUtils(unittest.TestCase):
+    def test_extract_schema_from_snapshot(self):
+        snapshot_path = '00000000000000000003.snap'
+        v = utils.extract_schema_from_snapshot(snapshot_path)
+        self.assertEqual(v, (2, 3, 1))
+
+    @settings(max_examples=5)
+    @given(port=integers(65000, 65535))
+    def test_check_port(self, port):
+        def open_socket(p):
+            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s.bind(('localhost', p))
+            s.listen(0)
+            return s
+        status = utils.check_port(port, ipv4=True, ipv6=False)
+        self.assertEqual(status, True)
+        s = open_socket(port)
+        status = utils.check_port(port, ipv4=True, ipv6=False)
+        s.close()
+        self.assertEqual(status, False)
+
+
+if __name__ == "__main__":
+    unittest.main()