informix-db/tests/test_errors.py

"""Phase 5.a integration tests — error message decoding + PEP 249 classification.

Server SQ_ERR responses get decoded to:
  - the appropriate PEP 249 exception class (Programming/Integrity/...)
  - a human-readable message with sqlcode, near-token, ISAM code, offset
  - structured ``sqlcode``, ``isamcode``, ``offset``, ``near`` attributes

The connection survives errors — subsequent queries work normally.
"""

from __future__ import annotations

import pytest

import informix_db
from tests.conftest import ConnParams

pytestmark = pytest.mark.integration


def _connect(conn_params: ConnParams) -> informix_db.Connection:
    return informix_db.connect(
        host=conn_params.host,
        port=conn_params.port,
        user=conn_params.user,
        password=conn_params.password,
        database=conn_params.database,
        server=conn_params.server,
        connect_timeout=10.0,
        read_timeout=10.0,
    )


def test_syntax_error_is_programming_error(conn_params: ConnParams) -> None:
    """sqlcode -201 (syntax error) → ProgrammingError."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        with pytest.raises(informix_db.ProgrammingError) as excinfo:
            cur.execute("SELEKT * FROM systables")
        e = excinfo.value
        assert e.sqlcode == -201
        assert "syntax error" in str(e).lower()


def test_table_not_found_is_programming_error(conn_params: ConnParams) -> None:
    """sqlcode -206 (table not found) → ProgrammingError; near-token has table name."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        with pytest.raises(informix_db.ProgrammingError) as excinfo:
            cur.execute("SELECT * FROM no_such_table_xyz")
        e = excinfo.value
        assert e.sqlcode == -206
        assert e.near == "no_such_table_xyz"
        assert "not in the database" in str(e)


def test_column_not_found_is_programming_error(conn_params: ConnParams) -> None:
    """sqlcode -217 (column not found) → ProgrammingError; near-token has column name."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        with pytest.raises(informix_db.ProgrammingError) as excinfo:
            cur.execute("SELECT no_such_column FROM systables")
        e = excinfo.value
        assert e.sqlcode == -217
        assert e.near == "no_such_column"


def test_unique_violation_is_integrity_error(conn_params: ConnParams) -> None:
    """sqlcode -268 (UNIQUE violation) → IntegrityError."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        cur.execute("CREATE TEMP TABLE t_uniq (id INTEGER PRIMARY KEY)")
        cur.execute("INSERT INTO t_uniq VALUES (?)", (1,))
        with pytest.raises(informix_db.IntegrityError) as excinfo:
            cur.execute("INSERT INTO t_uniq VALUES (?)", (1,))
        e = excinfo.value
        assert e.sqlcode == -268
        assert "duplicate" in str(e).lower()


def test_not_null_violation_is_integrity_error(conn_params: ConnParams) -> None:
    """sqlcode -391 (NOT NULL violation) → IntegrityError."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        cur.execute("CREATE TEMP TABLE t_nn (id INTEGER NOT NULL)")
        with pytest.raises(informix_db.IntegrityError) as excinfo:
            cur.execute("INSERT INTO t_nn VALUES (?)", (None,))
        assert excinfo.value.sqlcode == -391


def test_commit_in_unlogged_db_is_operational_error(conn_params: ConnParams) -> None:
    """sqlcode -255 (no transaction) → OperationalError."""
    with _connect(conn_params) as conn:
        with pytest.raises(informix_db.OperationalError) as excinfo:
            conn.commit()
        assert excinfo.value.sqlcode == -255


def test_connection_survives_query_error(conn_params: ConnParams) -> None:
    """Critical: a failed query must not poison the connection — subsequent queries must work."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        # First query fails
        with pytest.raises(informix_db.ProgrammingError):
            cur.execute("SELECT * FROM no_such_table")
        # Second query works
        cur.execute("SELECT 1 FROM systables WHERE tabid = 1")
        assert cur.fetchone() == (1,)


def test_error_has_structured_fields(conn_params: ConnParams) -> None:
    """``sqlcode``, ``isamcode``, ``offset``, ``near`` are attached for inspection."""
    with _connect(conn_params) as conn:
        cur = conn.cursor()
        with pytest.raises(informix_db.Error) as excinfo:
            cur.execute("SELECT * FROM no_such_table")
        e = excinfo.value
        # All four structured attributes present
        assert hasattr(e, "sqlcode")
        assert hasattr(e, "isamcode")
        assert hasattr(e, "offset")
        assert hasattr(e, "near")
        assert e.sqlcode == -206
        assert e.near == "no_such_table"