rspec/rules/S5906/python/rule.adoc

The ``++unittest++`` module provides assertion methods specific to common types and operations. Both versions will test the same things, but the dedicated one will provide a better error message, simplifying the debugging process.


This rule reports an issue when an assertion can be simplified by using a more specific function. The array below gives a list of assertions on which an issue will be raised, and which function should be used instead:



||Original||Dedicated||

|``++assertTrue(x == y)++``|``++assertEqual(x, y)++``|

|``++assertTrue(x != y)++``|``++assertNotEqual(x, y)++``|

|``++assertFalse(x == y)++``|``++assertNotEqual(x, y)++``|

|``++assertFalse(x != y)++``|``++assertEqual(x, y)++``|

|``++assertTrue(x < y)++``|``++assertLess(x, y)++``|

|``++assertTrue(x <= y)++``|``++assertLessEqual(x, y)++``|

|``++assertTrue(x > y)++``|``++assertGreater(x, y)++``|

|``++assertTrue(x >= y)++``|``++assertGreaterEqual(x, y)++``|

|``++assertTrue(x is y)++``|``++assertIs(x, y)++``|

|``++assertTrue(x is not y)++``|``++assertIsNot(x, y)++``|

|``++assertFalse(x is y)++``|``++assertIsNot(x, y)++``|

|``++assertFalse(x is not y)++``|``++assertIs(x, y)++``|

|``++assertTrue(x in y)++``|``++assertIn(x, y)++``|

|``++assertFalse(x in y)++``|``++assertNotIn(x, y)++``|

|``++assertTrue(isinstance(x, y))++``|``++assertIsInstance(x, y)++``|

|``++assertFalse(isinstance(x, y))++``|``++assertNotIsInstance(x, y)++``|

|``++assertEqual(x, round(y, z))++``|``++assertAlmostEqual(x, y, z)++``|

|``++assertAlmostEqual(x, round(y, z))++``|``++assertAlmostEqual(x, y, z)++``|

|``++assertNotEqual(x, round(y, z))++``|``++assertNotAlmostEqual(x, y, z)++``|

|``++assertNotAlmostEqual(x, round(y, z))++``|``++assertNotAlmostEqual(x, y, z)++``|

|``++assertEqual(x, None)++``|``++assertIsNone(x)++``|

|``++assertNotEqual(x, None)++``|``++assertIsNotNone(x)++``|

|``++assertTrue(x is None)++``|``++assertIsNone(x)++``|

|``++assertTrue(x is not None)++``|``++assertIsNotNone(x)++``|

|``++assertFalse(x is None)++``|``++assertIsNotNone(x)++``|

|``++assertFalse(x is not None)++``|``++assertIsNone(x)++``|

|``++assertEqual(x, True)++``|``++assertTrue(x)++``|

|``++assertEqual(x, False)++``|``++assertFalse(x)++``|


== Noncompliant Code Example

[source,python]
----
import unittest
class SomeTest(unittest.TestCase):
  def test_something(self):
    x = foo()
    y = bar()
    self.assertFalse(x == y)  # Noncompliant
    self.assertTrue(x < y)  # Noncompliant
----


== Compliant Solution

[source,python]
----
class SomeTest(unittest.TestCase):
  def test_something(self):
    x = foo()
    y = bar()
    self.assertNotEqual(x, y)
    self.assertLess(x, y)
----


== See

https://docs.python.org/3/library/unittest.html#unittest.TestCase.assertEqual[Python documentation - the ``++unittest++`` module]

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== Implementation Specification
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