test_utils.py

"""Tests for django.db.backends.utils"""
from decimal import Decimal, Rounded

from django.db import NotSupportedError, connection
from django.db.backends.utils import (
    format_number,
    split_identifier,
    split_tzname_delta,
    truncate_name,
)
from django.test import (
    SimpleTestCase,
    TransactionTestCase,
    skipIfDBFeature,
    skipUnlessDBFeature,
)


class TestUtils(SimpleTestCase):
    def test_truncate_name(self):
        self.assertEqual(truncate_name("some_table", 10), "some_table")
        self.assertEqual(truncate_name("some_long_table", 10), "some_la38a")
        self.assertEqual(truncate_name("some_long_table", 10, 3), "some_loa38")
        self.assertEqual(truncate_name("some_long_table"), "some_long_table")
        # "user"."table" syntax
        self.assertEqual(
            truncate_name('username"."some_table', 10), 'username"."some_table'
        )
        self.assertEqual(
            truncate_name('username"."some_long_table', 10), 'username"."some_la38a'
        )
        self.assertEqual(
            truncate_name('username"."some_long_table', 10, 3), 'username"."some_loa38'
        )

    def test_split_identifier(self):
        self.assertEqual(split_identifier("some_table"), ("", "some_table"))
        self.assertEqual(split_identifier('"some_table"'), ("", "some_table"))
        self.assertEqual(
            split_identifier('namespace"."some_table'), ("namespace", "some_table")
        )
        self.assertEqual(
            split_identifier('"namespace"."some_table"'), ("namespace", "some_table")
        )

    def test_format_number(self):
        def equal(value, max_d, places, result):
            self.assertEqual(format_number(Decimal(value), max_d, places), result)

        equal("0", 12, 3, "0.000")
        equal("0", 12, 8, "0.00000000")
        equal("1", 12, 9, "1.000000000")
        equal("0.00000000", 12, 8, "0.00000000")
        equal("0.000000004", 12, 8, "0.00000000")
        equal("0.000000008", 12, 8, "0.00000001")
        equal("0.000000000000000000999", 10, 8, "0.00000000")
        equal("0.1234567890", 12, 10, "0.1234567890")
        equal("0.1234567890", 12, 9, "0.123456789")
        equal("0.1234567890", 12, 8, "0.12345679")
        equal("0.1234567890", 12, 5, "0.12346")
        equal("0.1234567890", 12, 3, "0.123")
        equal("0.1234567890", 12, 1, "0.1")
        equal("0.1234567890", 12, 0, "0")
        equal("0.1234567890", None, 0, "0")
        equal("1234567890.1234567890", None, 0, "1234567890")
        equal("1234567890.1234567890", None, 2, "1234567890.12")
        equal("0.1234", 5, None, "0.1234")
        equal("123.12", 5, None, "123.12")

        with self.assertRaises(Rounded):
            equal("0.1234567890", 5, None, "0.12346")
        with self.assertRaises(Rounded):
            equal("1234567890.1234", 5, None, "1234600000")

    def test_split_tzname_delta(self):
        tests = [
            ("Asia/Ust+Nera", ("Asia/Ust+Nera", None, None)),
            ("Asia/Ust-Nera", ("Asia/Ust-Nera", None, None)),
            ("Asia/Ust+Nera-02:00", ("Asia/Ust+Nera", "-", "02:00")),
            ("Asia/Ust-Nera+05:00", ("Asia/Ust-Nera", "+", "05:00")),
            ("America/Coral_Harbour-01:00", ("America/Coral_Harbour", "-", "01:00")),
            ("America/Coral_Harbour+02:30", ("America/Coral_Harbour", "+", "02:30")),
            ("UTC+15:00", ("UTC", "+", "15:00")),
            ("UTC-04:43", ("UTC", "-", "04:43")),
            ("UTC", ("UTC", None, None)),
            ("UTC+1", ("UTC+1", None, None)),
        ]
        for tzname, expected in tests:
            with self.subTest(tzname=tzname):
                self.assertEqual(split_tzname_delta(tzname), expected)


class CursorWrapperTests(TransactionTestCase):
    available_apps = []

    def _test_procedure(self, procedure_sql, params, param_types, kparams=None):
        with connection.cursor() as cursor:
            cursor.execute(procedure_sql)
        # Use a new cursor because in MySQL a procedure can't be used in the
        # same cursor in which it was created.
        with connection.cursor() as cursor:
            cursor.callproc("test_procedure", params, kparams)
        with connection.schema_editor() as editor:
            editor.remove_procedure("test_procedure", param_types)

    @skipUnlessDBFeature("create_test_procedure_without_params_sql")
    def test_callproc_without_params(self):
        self._test_procedure(
            connection.features.create_test_procedure_without_params_sql, [], []
        )

    @skipUnlessDBFeature("create_test_procedure_with_int_param_sql")
    def test_callproc_with_int_params(self):
        self._test_procedure(
            connection.features.create_test_procedure_with_int_param_sql,
            [1],
            ["INTEGER"],
        )

    @skipUnlessDBFeature(
        "create_test_procedure_with_int_param_sql", "supports_callproc_kwargs"
    )
    def test_callproc_kparams(self):
        self._test_procedure(
            connection.features.create_test_procedure_with_int_param_sql,
            [],
            ["INTEGER"],
            {"P_I": 1},
        )

    @skipIfDBFeature("supports_callproc_kwargs")
    def test_unsupported_callproc_kparams_raises_error(self):
        msg = (
            "Keyword parameters for callproc are not supported on this database "
            "backend."
        )
        with self.assertRaisesMessage(NotSupportedError, msg):
            with connection.cursor() as cursor:
                cursor.callproc("test_procedure", [], {"P_I": 1})