diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 00000000..115443a4
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,14 @@
+[run]
+branch = True
+concurrency =
+    gevent
+    multiprocessing
+
+[report]
+precision = 1
+include =
+    ./*
+omit =
+    lib/tarantool-python/*
+    lib/msgpack-python/*
+    test/*
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c1ad3718..067abfa7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -58,3 +58,13 @@ jobs:
     - name: run regression tests
       run: |
        make test
+    - name: code coverage
+      if: ${{ matrix.python-version == '3.8' && matrix.tarantool-version == '2.7' }}
+      run: |
+       pip install coveralls==3.*
+       make coverage
+    - name: upload coverage data to coveralls.io
+      if: ${{ matrix.python-version == '3.8' && matrix.tarantool-version == '2.7' }}
+      run: coveralls --service=github
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.gitignore b/.gitignore
index c494f6c5..c4e42632 100644
--- a/.gitignore
+++ b/.gitignore
@@ -41,6 +41,7 @@ htmlcov/
 .coverage
 .coverage.*
 .cache
+.hypothesis/
 nosetests.xml
 coverage.xml
 *,cover
diff --git a/Makefile b/Makefile
index 5fb4c2a1..39bc1df6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+MAKEFILE_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))
+PROJECT_DIR := $(patsubst %/,%,$(dir $(MAKEFILE_PATH)))
 TEST_RUN_EXTRA_PARAMS?=
 PYTHON?=python
 
@@ -13,8 +15,19 @@ luacheck:
 	luacheck --config .luacheckrc .
 
 test_integration:
-	$(PYTHON) test/test-run.py --force $(TEST_RUN_EXTRA_PARAMS)
+	PYTHONPATH=$(PROJECT_DIR) $(PYTHON) test/test-run.py --force $(TEST_RUN_EXTRA_PARAMS)
 
-test: test_integration
+test_unittest:
+	$(PYTHON) -m unittest discover test/unittest/
 
-.PHONY: lint flake8 luacheck test test_integration
+test: test_unittest test_integration
+
+coverage:
+	PYTHON="coverage run" make -f $(MAKEFILE_PATH) test
+	coverage combine $(PROJECT_DIR) $(PROJECT_DIR)/test
+	coverage report
+
+clean:
+	coverage erase
+
+.PHONY: lint flake8 luacheck test test_integration test_unittest
diff --git a/README.md b/README.md
index 4566579b..cf77b6f6 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Tarantool Functional testing framework
 
+[![Coverage Status](https://coveralls.io/repos/github/tarantool/test-run/badge.svg)](https://coveralls.io/github/tarantool/test-run)
+
 ### Test Suite
 
 Bunch of tests, that lay down in the subfolder (recursively) with `suite.ini`
diff --git a/lib/tarantool_server.py b/lib/tarantool_server.py
index 8c8222ae..0f489e35 100644
--- a/lib/tarantool_server.py
+++ b/lib/tarantool_server.py
@@ -905,8 +905,8 @@ def start(self, silent=True, wait=True, wait_load=True, rais=True, args=[],
         # Verify that the schema actually was not upgraded.
         if self.disable_schema_upgrade:
             expected_version = extract_schema_from_snapshot(self.snapshot_path)
-            actual_version = yaml.safe_load(self.admin.execute(
-                'box.space._schema:get{"version"}'))[0]
+            actual_version = tuple(yaml.safe_load(self.admin.execute(
+                'box.space._schema:get{"version"}'))[0][1:])
             if expected_version != actual_version:
                 color_stdout('Schema version check fails: expected '
                              '{}, got {}\n'.format(expected_version,
diff --git a/lib/utils.py b/lib/utils.py
index a92db07c..54780b9b 100644
--- a/lib/utils.py
+++ b/lib/utils.py
@@ -1,3 +1,4 @@
+import errno
 import os
 import sys
 import collections
@@ -24,6 +25,9 @@
 PY3 = sys.version_info[0] == 3
 PY2 = sys.version_info[0] == 2
 
+if PY2:
+    FileNotFoundError = IOError
+
 if PY3:
     string_types = str,
     integer_types = int,
@@ -283,11 +287,13 @@ def xlog_rows(xlog_path):
 
         Assume tarantool and tarantoolctl is in PATH.
     """
+    if not os.path.exists(xlog_path):
+        raise FileNotFoundError(errno.ENOENT, os.strerror(errno.ENOENT), 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)
+        yield json.loads(bytes_to_str(line))
 
 
 def extract_schema_from_snapshot(snapshot_path):
@@ -303,7 +309,7 @@ def extract_schema_from_snapshot(snapshot_path):
        "BODY": {"space_id": 272, "tuple": ["version", 2, 3, 1]}
      }
 
-    :returns: [u'version', 2, 3, 1]
+    :returns: (2, 3, 1)
     """
     BOX_SCHEMA_ID = 272
     for row in xlog_rows(snapshot_path):
@@ -311,7 +317,7 @@ def extract_schema_from_snapshot(snapshot_path):
            row['BODY']['space_id'] == BOX_SCHEMA_ID:
             res = row['BODY']['tuple']
             if res[0] == 'version':
-                return res
+                return tuple(res[1:])
     return None
 
 
diff --git a/requirements-test.txt b/requirements-test.txt
index 5c71e7df..d5e80422 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1 +1,3 @@
+coverage==5.*
 flake8==3.7.9
+hypothesis==4.*
diff --git a/test/test-tarantool/call.result b/test/test-tarantool/call.result
new file mode 100644
index 00000000..b8d621d2
--- /dev/null
+++ b/test/test-tarantool/call.result
@@ -0,0 +1,592 @@
+box.schema.user.create('test', { password = 'test' })
+---
+...
+box.schema.user.grant('test', 'execute,read,write', 'universe')
+---
+...
+exp_notation = 1e123
+---
+...
+function f1() return 'testing', 1, false, -1, 1.123, math.abs(exp_notation - 1e123) < 0.1, nil end
+---
+...
+f1()
+---
+- testing
+- 1
+- false
+- -1
+- 1.123
+- true
+- null
+...
+call  f1 ()
+- 'testing'
+- 1
+- False
+- -1
+- 1.123
+- True
+- None
+f1=nil
+---
+...
+call  f1 ()
+{
+    "error": {
+        "code": "ER_NO_SUCH_PROC", 
+        "reason": "Procedure 'f1' is not defined"
+    }
+}
+function f1() return f1 end
+---
+...
+call  f1 ()
+{
+    "error": {
+        "code": "ER_PROC_LUA", 
+        "reason": "unsupported Lua type 'function'"
+    }
+}
+call  box.error (33333, 'Hey!')
+{
+    "error": {
+        "code": "U", 
+        "reason": "Unknown error"
+    }
+}
+
+# A test case for Bug#103491
+# server CALL processing bug with name path longer than two
+# https://bugs.launchpad.net/tarantool/+bug/1034912
+
+f = function() return 'OK' end
+---
+...
+test = {}
+---
+...
+test.f = f
+---
+...
+test.test = {}
+---
+...
+test.test.f = f
+---
+...
+call  f ()
+- 'OK'
+call  test.f ()
+- 'OK'
+call  test.test.f ()
+- 'OK'
+
+# Test for Bug #955226
+# Lua Numbers are passed back wrongly as strings
+#
+
+function foo() return 1, 2, '1', '2' end
+---
+...
+call  foo ()
+- 1
+- 2
+- '1'
+- '2'
+function f1(...) return {...} end
+---
+...
+function f2(...) return f1({...}) end
+---
+...
+call  f1 ('test_', 'test_')
+- ['test_', 'test_']
+call  f2 ('test_', 'test_')
+- [['test_', 'test_']]
+call  f1 ()
+- []
+call  f2 ()
+- [[]]
+function f3() return {{'hello'}, {'world'}} end
+---
+...
+call  f3 ()
+- [['hello'], ['world']]
+function f3() return {'hello', {'world'}} end
+---
+...
+call  f3 ()
+- ['hello', ['world']]
+function f3() return 'hello', {{'world'}, {'canada'}} end
+---
+...
+call  f3 ()
+- 'hello'
+- [['world'], ['canada']]
+function f3() return {}, '123', {{}, {}} end
+---
+...
+call  f3 ()
+- []
+- '123'
+- [[], []]
+function f3() return { {{'hello'}} } end
+---
+...
+call  f3 ()
+- [[['hello']]]
+function f3() return { box.tuple.new('hello'), {'world'} } end
+---
+...
+call  f3 ()
+- [['hello'], ['world']]
+function f3() return { {'world'}, box.tuple.new('hello') } end
+---
+...
+call  f3 ()
+- [['world'], ['hello']]
+function f3() return { { test={1,2,3} }, { test2={1,2,3} } } end
+---
+...
+call  f3 ()
+- [{'test': [1, 2, 3]}, {'test2': [1, 2, 3]}]
+call  f1 ('jason',)
+- ['jason']
+call  f1 ('jason', 1, 'test', 2, 'stewart')
+- ['jason', 1, 'test', 2, 'stewart']
+space = box.schema.space.create('tweedledum')
+---
+...
+index = space:create_index('primary', { type = 'hash' })
+---
+...
+function myreplace(...) return space:replace{...} end
+---
+...
+function myinsert(...) return space:insert{...} end
+---
+...
+call  myinsert (1, 'test box delete')
+- [1, 'test box delete']
+call  space:delete (1,)
+- [1, 'test box delete']
+call  myinsert (1, 'test box delete')
+- [1, 'test box delete']
+call  space:delete (1,)
+- [1, 'test box delete']
+call  space:delete (1,)
+
+call  myinsert (2, 'test box delete')
+- [2, 'test box delete']
+call  space:delete (1,)
+
+call  space:delete (2,)
+- [2, 'test box delete']
+call  space:delete (2,)
+
+space:delete{2}
+---
+...
+call  myinsert (2, 'test box delete')
+- [2, 'test box delete']
+call  space:get (2,)
+- [2, 'test box delete']
+space:delete{2}
+---
+- [2, 'test box delete']
+...
+call  space:get (2,)
+
+call  myinsert (2, 'test box.select()')
+- [2, 'test box.select()']
+call  space:get (2,)
+- [2, 'test box.select()']
+call  space:select (2,)
+- [[2, 'test box.select()']]
+space:get{2}
+---
+- [2, 'test box.select()']
+...
+space:select{2}
+---
+- - [2, 'test box.select()']
+...
+space:get{1}
+---
+...
+space:select{1}
+---
+- []
+...
+call  myreplace (2, 'hello', 'world')
+- [2, 'hello', 'world']
+call  myreplace (2, 'goodbye', 'universe')
+- [2, 'goodbye', 'universe']
+call  space:get (2,)
+- [2, 'goodbye', 'universe']
+call  space:select (2,)
+- [[2, 'goodbye', 'universe']]
+space:get{2}
+---
+- [2, 'goodbye', 'universe']
+...
+space:select{2}
+---
+- - [2, 'goodbye', 'universe']
+...
+call  myreplace (2,)
+- [2]
+call  space:get (2,)
+- [2]
+call  space:select (2,)
+- [[2]]
+call  space:delete (2,)
+- [2]
+call  space:delete (2,)
+
+call  myinsert (3, 'old', 2)
+- [3, 'old', 2]
+space:update({3}, {{'=', 1, 4}, {'=', 2, 'new'}})
+---
+- error: Attempt to modify a tuple field which is part of index 'primary' in space
+    'tweedledum'
+...
+space:insert(space:get{3}:update{{'=', 1, 4}, {'=', 2, 'new'}}) space:delete{3}
+---
+...
+call  space:get (4,)
+- [4, 'new', 2]
+call  space:select (4,)
+- [[4, 'new', 2]]
+space:update({4}, {{'+', 3, 1}})
+---
+- [4, 'new', 3]
+...
+space:update({4}, {{'-', 3, 1}})
+---
+- [4, 'new', 2]
+...
+call  space:get (4,)
+- [4, 'new', 2]
+call  space:select (4,)
+- [[4, 'new', 2]]
+function field_x(key, field_index) return space:get(key)[field_index] end
+---
+...
+call  field_x (4, 1)
+- 4
+call  field_x (4, 2)
+- 'new'
+call  space:delete (4,)
+- [4, 'new', 2]
+space:drop()
+---
+...
+space = box.schema.space.create('tweedledum')
+---
+...
+index = space:create_index('primary', { type = 'tree' })
+---
+...
+eval (return 1)()
+---
+- 1
+function f(...) return 1 end
+---
+...
+call f()
+---
+- 1
+eval (return 1, 2, 3)()
+---
+- 1
+- 2
+- 3
+function f(...) return 1, 2, 3 end
+---
+...
+call f()
+---
+- 1
+- 2
+- 3
+eval (return true)()
+---
+- true
+function f(...) return true end
+---
+...
+call f()
+---
+- true
+eval (return nil)()
+---
+- null
+function f(...) return nil end
+---
+...
+call f()
+---
+- null
+eval (return )()
+---
+
+function f(...) return  end
+---
+...
+call f()
+---
+
+eval (return {})()
+---
+- []
+function f(...) return {} end
+---
+...
+call f()
+---
+- []
+eval (return {1})()
+---
+- [1]
+function f(...) return {1} end
+---
+...
+call f()
+---
+- [1]
+eval (return {1, 2, 3})()
+---
+- [1, 2, 3]
+function f(...) return {1, 2, 3} end
+---
+...
+call f()
+---
+- [1, 2, 3]
+eval (return {k1 = 'v1', k2 = 'v2'})()
+---
+- {"k1": "v1", "k2": "v2"}
+function f(...) return {k1 = 'v1', k2 = 'v2'} end
+---
+...
+call f()
+---
+- {"k1": "v1", "k2": "v2"}
+eval (return {k1 = 'v1', k2 = 'v2'})()
+---
+- {"k1": "v1", "k2": "v2"}
+function f(...) return {k1 = 'v1', k2 = 'v2'} end
+---
+...
+call f()
+---
+- {"k1": "v1", "k2": "v2"}
+eval (return {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}})()
+---
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+function f(...) return {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}} end
+---
+...
+call f()
+---
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+eval (return true, {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}})()
+---
+- true
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+function f(...) return true, {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}} end
+---
+...
+call f()
+---
+- true
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+eval (return {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}}, true)()
+---
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+- true
+function f(...) return {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}}, true end
+---
+...
+call f()
+---
+- {"c": {"106": [1, 1428578535], "2": [1, 1428578535]}, "pc": {"106": [1, 1428578535, 9243], "2": [1, 1428578535, 9243]}, "s": [1, 1428578535], "u": 1428578535, "v": []}
+- true
+t = box.tuple.new('tuple', {1, 2, 3}, { k1 = 'v', k2 = 'v2'})
+---
+...
+eval (return t)()
+---
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+function f(...) return t end
+---
+...
+call f()
+---
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+eval (return t, t, t)()
+---
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+function f(...) return t, t, t end
+---
+...
+call f()
+---
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+- ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]
+eval (return {t})()
+---
+- [["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]]
+function f(...) return {t} end
+---
+...
+call f()
+---
+- [["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]]
+eval (return {t, t, t})()
+---
+- [["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}], ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}], ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]]
+function f(...) return {t, t, t} end
+---
+...
+call f()
+---
+- [["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}], ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}], ["tuple", [1, 2, 3], {"k1": "v", "k2": "v2"}]]
+eval (return error('exception'))()
+---
+{
+    "error": {
+        "code": "ER_PROC_LUA", 
+        "reason": "exception"
+    }
+}
+function f(...) return error('exception') end
+---
+...
+call f()
+---
+{
+    "error": {
+        "code": "ER_PROC_LUA", 
+        "reason": "exception"
+    }
+}
+eval (return box.error(0))()
+---
+
+function f(...) return box.error(0) end
+---
+...
+call f()
+---
+
+eval (return ...)()
+---
+
+function f(...) return ... end
+---
+...
+call f()
+---
+
+eval (return ...)(1, 2, 3)
+---
+- 1
+- 2
+- 3
+function f(...) return ... end
+---
+...
+call f(1, 2, 3)
+---
+- 1
+- 2
+- 3
+eval (return ...)(null, null, null)
+---
+- null
+- null
+- null
+function f(...) return ... end
+---
+...
+call f(null, null, null)
+---
+- null
+- null
+- null
+eval (return ...)({"k1": "v1", "k2": "v2"})
+---
+- {"k1": "v1", "k2": "v2"}
+function f(...) return ... end
+---
+...
+call f({"k1": "v1", "k2": "v2"})
+---
+- {"k1": "v1", "k2": "v2"}
+eval (return space:auto_increment({"transaction"}))()
+---
+- [1, "transaction"]
+function f(...) return space:auto_increment({"transaction"}) end
+---
+...
+call f()
+---
+- [2, "transaction"]
+eval (return space:select{})()
+---
+- [[1, "transaction"], [2, "transaction"]]
+function f(...) return space:select{} end
+---
+...
+call f()
+---
+- [[1, "transaction"], [2, "transaction"]]
+eval (return box.begin(), space:auto_increment({"failed"}), box.rollback())()
+---
+- null
+- [3, "failed"]
+function f(...) return box.begin(), space:auto_increment({"failed"}), box.rollback() end
+---
+...
+call f()
+---
+- null
+- [3, "failed"]
+eval (return space:select{})()
+---
+- [[1, "transaction"], [2, "transaction"]]
+function f(...) return space:select{} end
+---
+...
+call f()
+---
+- [[1, "transaction"], [2, "transaction"]]
+eval (return require("fiber").sleep(0))()
+---
+
+function f(...) return require("fiber").sleep(0) end
+---
+...
+call f()
+---
+
+eval (!invalid expression)()
+---
+{
+    "error": {
+        "code": "ER_PROC_LUA", 
+        "reason": "eval:1: unexpected symbol near '!'"
+    }
+}
+space:drop()
+---
+...
+box.schema.user.drop('test')
+---
+...
diff --git a/test/test-tarantool/call.test.py b/test/test-tarantool/call.test.py
new file mode 100644
index 00000000..eaf6a0d2
--- /dev/null
+++ b/test/test-tarantool/call.test.py
@@ -0,0 +1,214 @@
+"""
+Tarantool's test box-py/call.test.py had a problem fixed in
+tarantool-python library by commit:
+8847b8c8bd1092d87601987d858e3cb9ff54f9f6
+("python3: make json.dumps compatible with Python 2").
+"""
+
+from __future__ import print_function
+
+import os
+import sys
+import json
+
+def call(name, *args):
+    return iproto.call(name, *args)
+
+admin("box.schema.user.create('test', { password = 'test' })")
+admin("box.schema.user.grant('test', 'execute,read,write', 'universe')")
+iproto.authenticate("test", "test")
+# workaround for gh-770 centos 6 float representation
+admin("exp_notation = 1e123")
+admin("function f1() return 'testing', 1, false, -1, 1.123, math.abs(exp_notation - 1e123) < 0.1, nil end")
+admin("f1()")
+call("f1")
+admin("f1=nil")
+call("f1")
+admin("function f1() return f1 end")
+call("f1")
+
+# A test case for https://github.com/tarantool/tarantool/issues/44
+# IPROTO required!
+call("box.error", 33333, "Hey!")
+
+print("""
+# A test case for Bug#103491
+# server CALL processing bug with name path longer than two
+# https://bugs.launchpad.net/tarantool/+bug/1034912
+""")
+admin("f = function() return 'OK' end")
+admin("test = {}")
+admin("test.f = f")
+admin("test.test = {}")
+admin("test.test.f = f")
+call("f")
+call("test.f")
+call("test.test.f")
+
+print("""
+# Test for Bug #955226
+# Lua Numbers are passed back wrongly as strings
+#
+""")
+admin("function foo() return 1, 2, '1', '2' end")
+call("foo")
+
+#
+# check how well we can return tables
+#
+admin("function f1(...) return {...} end")
+admin("function f2(...) return f1({...}) end")
+call("f1", "test_", "test_")
+call("f2", "test_", "test_")
+call("f1")
+call("f2")
+#
+# check multi-tuple return
+#
+admin("function f3() return {{'hello'}, {'world'}} end")
+call("f3")
+admin("function f3() return {'hello', {'world'}} end")
+call("f3")
+admin("function f3() return 'hello', {{'world'}, {'canada'}} end")
+call("f3")
+admin("function f3() return {}, '123', {{}, {}} end")
+call("f3")
+admin("function f3() return { {{'hello'}} } end")
+call("f3")
+admin("function f3() return { box.tuple.new('hello'), {'world'} } end")
+call("f3")
+admin("function f3() return { {'world'}, box.tuple.new('hello') } end")
+call("f3")
+admin("function f3() return { { test={1,2,3} }, { test2={1,2,3} } } end")
+call("f3")
+
+call("f1", "jason")
+call("f1", "jason", 1, "test", 2, "stewart")
+
+admin("space = box.schema.space.create('tweedledum')")
+admin("index = space:create_index('primary', { type = 'hash' })")
+
+admin("function myreplace(...) return space:replace{...} end")
+admin("function myinsert(...) return space:insert{...} end")
+
+call("myinsert", 1, "test box delete")
+call("space:delete", 1)
+call("myinsert", 1, "test box delete")
+call("space:delete", 1)
+call("space:delete", 1)
+call("myinsert", 2, "test box delete")
+call("space:delete", 1)
+call("space:delete", 2)
+call("space:delete", 2)
+admin("space:delete{2}")
+
+call("myinsert", 2, "test box delete")
+call("space:get", 2)
+admin("space:delete{2}")
+call("space:get", 2)
+call("myinsert", 2, "test box.select()")
+call("space:get", 2)
+call("space:select", 2)
+admin("space:get{2}")
+admin("space:select{2}")
+admin("space:get{1}")
+admin("space:select{1}")
+call("myreplace", 2, "hello", "world")
+call("myreplace", 2, "goodbye", "universe")
+call("space:get", 2)
+call("space:select", 2)
+admin("space:get{2}")
+admin("space:select{2}")
+call("myreplace", 2)
+call("space:get", 2)
+call("space:select", 2)
+call("space:delete", 2)
+call("space:delete", 2)
+call("myinsert", 3, "old", 2)
+admin("space:update({3}, {{'=', 1, 4}, {'=', 2, 'new'}})")
+admin("space:insert(space:get{3}:update{{'=', 1, 4}, {'=', 2, 'new'}}) space:delete{3}")
+call("space:get", 4)
+call("space:select", 4)
+admin("space:update({4}, {{'+', 3, 1}})")
+admin("space:update({4}, {{'-', 3, 1}})")
+call("space:get", 4)
+call("space:select", 4)
+admin("function field_x(key, field_index) return space:get(key)[field_index] end")
+call("field_x", 4, 1)
+call("field_x", 4, 2)
+call("space:delete", 4)
+admin("space:drop()")
+
+admin("space = box.schema.space.create('tweedledum')")
+admin("index = space:create_index('primary', { type = 'tree' })")
+
+json_dumps_kwargs=dict(sort_keys=True, separators=(', ', ': '))
+
+def dump_args(*args):
+    return json.dumps(args, **json_dumps_kwargs)[1:-1]
+
+def dump_response(response):
+    if response.return_code:
+        return str(response)
+    if not response.data:
+        return ''
+    res = []
+    for item in response.data:
+        res.append(json.dumps(item, **json_dumps_kwargs))
+    return '- ' + '\n- '.join(res)
+
+def lua_eval(name, *args):
+    print("eval ({})({})".format(name, dump_args(*args)))
+    print("---")
+    print(dump_response(iproto.py_con.eval(name, args)))
+
+def lua_call(name, *args):
+    print("call {}({})".format(name, dump_args(*args)))
+    print("---")
+    print(dump_response(iproto.py_con.call(name, args)))
+
+def test(expr, *args):
+    lua_eval("return " + expr, *args)
+    admin("function f(...) return " + expr + " end")
+    lua_call("f", *args)
+
+# Return values
+test("1")
+test("1, 2, 3")
+test("true")
+test("nil")
+test("")
+test("{}")
+test("{1}")
+test("{1, 2, 3}")
+test("{k1 = 'v1', k2 = 'v2'}")
+test("{k1 = 'v1', k2 = 'v2'}")
+# gh-791: maps are wrongly assumed to be arrays
+test("{s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}}")
+test("true, {s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}}")
+test("{s = {1, 1428578535}, u = 1428578535, v = {}, c = {['2'] = {1, 1428578535}, ['106'] = { 1, 1428578535} }, pc = {['2'] = {1, 1428578535, 9243}, ['106'] = {1, 1428578535, 9243}}}, true")
+admin("t = box.tuple.new('tuple', {1, 2, 3}, { k1 = 'v', k2 = 'v2'})")
+test("t")
+test("t, t, t")
+test("{t}")
+test("{t, t, t}")
+test("error('exception')")
+test("box.error(0)")
+test("...")
+test("...", 1, 2, 3)
+test("...",  None, None, None)
+test("...", { "k1": "v1", "k2": "v2"})
+# Transactions
+test("space:auto_increment({\"transaction\"})")
+test("space:select{}")
+test("box.begin(), space:auto_increment({\"failed\"}), box.rollback()")
+test("space:select{}")
+test("require(\"fiber\").sleep(0)")
+# Other
+lua_eval("!invalid expression")
+
+admin("space:drop()")
+admin("box.schema.user.drop('test')")
+
+# Re-connect after removing user
+iproto.py_con.close()
diff --git a/test/unittest/00000000000000000003.snap b/test/unittest/00000000000000000003.snap
new file mode 100644
index 00000000..0b2e62eb
Binary files /dev/null and b/test/unittest/00000000000000000003.snap differ
diff --git a/test/unittest/test_lib_utils.py b/test/unittest/test_lib_utils.py
new file mode 100644
index 00000000..8fe1ff72
--- /dev/null
+++ b/test/unittest/test_lib_utils.py
@@ -0,0 +1,32 @@
+import socket
+import unittest
+
+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 = 'test/unittest/00000000000000000003.snap'
+        v = utils.extract_schema_from_snapshot(snapshot_path)
+        self.assertEqual(v, (2, 3, 1))
+
+    @settings(max_examples=5)
+    @given(port=integers(65100, 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, rais=False, ipv4=True, ipv6=False)
+        self.assertEqual(status, True)
+        s = open_socket(port)
+        status = utils.check_port(port, rais=False, ipv4=True, ipv6=False)
+        s.close()
+        self.assertEqual(status, False)
+
+
+if __name__ == "__main__":
+    unittest.main()