Added automatic check of homework

Utilized using pytest framework.

Signed-off-by: Guy Hartuv <ghartuv@redhat.com>

docs/course_materials/exercises/03_Variables_and_datatypes/test_homework.py

@@ -0,0 +1,136 @@
+""" Automatically check student's homework
+
+The tests will check:
+ 1. The content of the exercise file
+ 2. The execution and output of the exercise file
+ 3. The output with different inputs
+
+Guidelines:
+- Student's exercise files should be placed in the same dir as this test.
+- Test names are in the form: test_<topic>_<exc>.py
+
+Usage:
+
+    # List all tests
+    pytest -o addopts="" --collect-only
+
+    # Run all tests:
+    pytest -o addopts=""
+
+    # Test a specific topic
+    pytest -o addopts="" -k test_variables
+"""
+import os
+import re
+from subprocess import PIPE, STDOUT, Popen, TimeoutExpired
+
+
+def test_variables_exc1():
+    answer_file = 'variables.py'
+    expected_pycode = [
+        r'^.*x *= *9.*',
+        r'^.*y *= *7.*',
+        r'^.*z *= *x *\+ *y.*',
+        r'^.*print.*z.*',
+    ]
+    expected_stdout = '16'
+
+    check_list_of_answers_from_file(expected_pycode, answer_file)
+
+    stdout = run_cmd(['python3', answer_file])
+    check_list_of_answers([expected_stdout], stdout.strip(), word_pattern=True)
+
+
+def test_variables_exc2():
+    answer_file = 'calculations.txt'
+    expected_answers = [
+        # What is the result of 10 ** 3?
+        '1000',
+        # Given (x = 1), what will be the value of after we run (x += 2)?
+        '3',
+        # What is the result of float(1)?
+        r'1\.0',
+        # What is the result of 10 == “10”?
+        'False',
+        # Print the result of the following variable:
+        # Number = ((((13 * 8 - 4) * 2 + 50) * 4 ) % 127 ) *5
+        '555',
+    ]
+    check_list_of_answers_from_file(expected_answers, answer_file, word_pattern=True)
+
+
+def test_variables_exc3():
+    # ??? TODO: ASK SHIRA file names
+    # Accept two numbers from the user (using input) and calculate multiplication (*)
+    # Accept two numbers from the user (using input) and calculate Subtract (-)
+    # Accept two numbers from the user (using input) and calculate Divide (/)
+    # Accept two numbers from the user (using input) and calculate Modulus (%)
+    pass
+
+
+def test_strings_names():
+    student_file = 'Names.py'
+    answers = [
+        # Create a string variable with your name, call it my_name
+        r'''\bmy_name\s*=\s*['"]\w+["']''',
+        # Create a string variable with your family name, call it my_family_name
+        r'''\bmy_family_name\s*=\s*['"]\w+["']''',
+        # Create a string variable called my_full_name which is composed from the 2 variables my_name and my_family_name.
+        r'''\bmy_full_name\s*=.*\bmy_name\b.*\bmy_family_name\b''',
+        # Create a variable with your city name: call it my_city_name
+        r'''\bmy_city_name\s*=\s*['"]\w+['"]''',
+        # Create a variable msg with "My name is X and I’m from Y" using the variables you created above
+        r'''\bmsg\s*=.*My name is .* and I'm from .*''',
+        r'''\bmsg\s*=.*\bmy_(full_)?name\b.*\bmy_city_name\b'''
+    ]
+    check_list_of_answers_from_file(answers, student_file)
+
+
+def test_strings_times():
+    student_file = 'Times.py'
+    expected_msg = 'You have to spend {} minutes this week to complete ROSE homework'
+
+    does_student_file_exist(student_file)
+    for inputs, expected_output in [
+        [['2', '3'], expected_msg.format(6)],
+        [['11', '6'], expected_msg.format(66)],
+        [['10', '2'], expected_msg.format(20)],
+    ]:
+        assert run_cmd(['python3', student_file], input_list=inputs) == expected_output
+
+
+def run_cmd(cmd_list, input_list=[], **kwargs):
+    input_data = '\n'.join(input_list).encode('utf-8') if input_list else None
+
+    p = Popen(cmd_list, stdout=PIPE, stdin=PIPE, stderr=STDOUT)
+    try:
+        stdout, stderr = p.communicate(input=input_data, timeout=20, **kwargs)
+    except TimeoutExpired:
+        p.kill()
+        stdout, stderr = p.communicate()
+    assert p.returncode == 0
+
+    return stdout.decode('utf-8')
+
+
+def check_list_of_answers_from_file(expected_answers_list, answer_file, word_pattern=False):
+    with open(answer_file, 'r') as f:
+        text = f.read()
+    check_list_of_answers(expected_answers_list, text, word_pattern)
+
+
+def check_list_of_answers(expected_answers_list, text, word_pattern=False):
+    for line in text.splitlines():
+        # print(f'line: |{line}|')
+        for answer in expected_answers_list.copy():
+            pattern = f'\\b{answer}\\b' if word_pattern else answer
+            # print(f'pattern: {pattern}')
+            if re.match(pattern, line):
+                # print("MATCHED")
+                expected_answers_list.remove(answer)
+
+    assert len(expected_answers_list) == 0, "Some expected answers were not found"
+
+
+def does_student_file_exist(filename):
+    assert os.path.exists(filename), f'Student homework file not found: {filename}'