import unittest
import psycopg2
import pandas as pd

class TestPostgresQuery(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        cls.connection = psycopg2.connect(
            host="localhost",
            user="agent",
            password="qwerty",
            dbname="testdb",
            sslmode="disable"
        )
        cls.cursor = cls.connection.cursor()

    def test_columns_and_types(self):
        """Check if required columns and types are present."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        columns = [desc[0] for desc in self.cursor.description]
        expected_columns = ['ab_group','user_id','event_count','user_rank']
        missing = [col for col in expected_columns if col not in columns]
        _dynamic_test(
            self,
            len(missing) == 0,
            "All required columns are present.",
            f"Missing columns: {', '.join(missing)}"
        )

    def test_ranking_within_ab_group(self):
        """Check that users are ranked correctly by event_count within each ab_group."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        rows = self.cursor.fetchall()
        columns = [desc[0] for desc in self.cursor.description]
        df = pd.DataFrame(rows, columns=columns)
        # For each ab_group, check rank order
        passed = True
        failure_msgs = []
        for grp in df['ab_group'].unique():
            sub = df[df['ab_group'] == grp].sort_values('user_rank')
            counts = sub['event_count'].tolist()
            ranks = sub['user_rank'].tolist()
            # Check that event_count is non-increasing as rank increases
            if any(counts[i] < counts[i+1] for i in range(len(counts)-1)):
                passed = False
                failure_msgs.append(f"In ab_group {grp}, event_count is not sorted by rank.")
            # Check that rank starts at 1
            if len(ranks) > 0 and ranks[0] != 1:
                passed = False
                failure_msgs.append(f"In ab_group {grp}, rank does not start at 1.")
        _dynamic_test(
            self,
            passed,
            "Ranking and ordering within ab_group is correct.",
            " ".join(failure_msgs)
        )

    def test_event_count_aggregation(self):
        """Check that event_count matches the number of events per user."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        rows = self.cursor.fetchall()
        columns = [desc[0] for desc in self.cursor.description]
        df = pd.DataFrame(rows, columns=columns)
        # Calculate ground truth
        self.cursor.execute("SELECT user_id, COUNT(event_id) FROM events GROUP BY user_id")
        truth = dict(self.cursor.fetchall())
        df['event_count'] = df['event_count'].astype(int)
        mismatches = []
        for _, row in df.iterrows():
            expected = truth.get(row['user_id'], 0)
            if row['event_count'] != expected:
                mismatches.append((row['user_id'], row['event_count'], expected))
        _dynamic_test(
            self,
            len(mismatches) == 0,
            "event_count matches the number of events per user.",
            f"event_count mismatches: {mismatches}"
        )

    def test_all_users_included(self):
        """Check that all users are present in the output."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        rows = self.cursor.fetchall()
        columns = [desc[0] for desc in self.cursor.description]
        df = pd.DataFrame(rows, columns=columns)
        self.cursor.execute("SELECT COUNT(*) FROM users")
        user_count = self.cursor.fetchone()[0]
        _dynamic_test(
            self,
            len(df) == user_count,
            "All users are present in the output.",
            f"Output has {len(df)} rows, expected {user_count}."
        )

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

def normalize_text(text):
    text = text.lower()
    text = re.sub(r"\\s{2,}", " ", text)
    text = re.sub(r"\\s*([,:?])\\s*", r"\\1 ", text)
    return text.strip()

if __name__ == "__main__":
    unittest.main()


test_solution.py

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Learn to track and analyze how users discover and adopt new product features using SQL.

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Challenge: Advanced Window Analytics

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Challenge: Advanced Window Analytics

Ratkaisu