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"""
Tests and examples for correct "+/-" usage in error diffs.
"""
import sys
import pytest
from _pytest.pytester import Pytester
TESTCASES = [
pytest.param(
"""
def test_this():
result = [1, 4, 3]
expected = [1, 2, 3]
assert result == expected
""",
"""
> assert result == expected
E assert [1, 4, 3] == [1, 2, 3]
E At index 1 diff: 4 != 2
E Full diff:
E - [1, 2, 3]
E ? ^
E + [1, 4, 3]
E ? ^
""",
id="Compare lists, one item differs",
),
pytest.param(
"""
def test_this():
result = [1, 2, 3]
expected = [1, 2]
assert result == expected
""",
"""
> assert result == expected
E assert [1, 2, 3] == [1, 2]
E Left contains one more item: 3
E Full diff:
E - [1, 2]
E + [1, 2, 3]
E ? +++
""",
id="Compare lists, one extra item",
),
pytest.param(
"""
def test_this():
result = [1, 3]
expected = [1, 2, 3]
assert result == expected
""",
"""
> assert result == expected
E assert [1, 3] == [1, 2, 3]
E At index 1 diff: 3 != 2
E Right contains one more item: 3
E Full diff:
E - [1, 2, 3]
E ? ---
E + [1, 3]
""",
id="Compare lists, one item missing",
),
pytest.param(
"""
def test_this():
result = (1, 4, 3)
expected = (1, 2, 3)
assert result == expected
""",
"""
> assert result == expected
E assert (1, 4, 3) == (1, 2, 3)
E At index 1 diff: 4 != 2
E Full diff:
E - (1, 2, 3)
E ? ^
E + (1, 4, 3)
E ? ^
""",
id="Compare tuples",
),
pytest.param(
"""
def test_this():
result = {1, 3, 4}
expected = {1, 2, 3}
assert result == expected
""",
"""
> assert result == expected
E assert {1, 3, 4} == {1, 2, 3}
E Extra items in the left set:
E 4
E Extra items in the right set:
E 2
E Full diff:
E - {1, 2, 3}
E ? ^ ^
E + {1, 3, 4}
E ? ^ ^
""",
id="Compare sets",
),
pytest.param(
"""
def test_this():
result = {1: 'spam', 3: 'eggs'}
expected = {1: 'spam', 2: 'eggs'}
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert {1: 'spam', 3: 'eggs'} == {1: 'spam', 2: 'eggs'}
E Common items:
E {1: 'spam'}
E Left contains 1 more item:
E {3: 'eggs'}
E Right contains 1 more item:
E {2: 'eggs'}
E Full diff:
E - {1: 'spam', 2: 'eggs'}
E ? ^
E + {1: 'spam', 3: 'eggs'}
E ? ^
""",
id="Compare dicts with differing keys",
),
pytest.param(
"""
def test_this():
result = {1: 'spam', 2: 'eggs'}
expected = {1: 'spam', 2: 'bacon'}
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert {1: 'spam', 2: 'eggs'} == {1: 'spam', 2: 'bacon'}
E Common items:
E {1: 'spam'}
E Differing items:
E {2: 'eggs'} != {2: 'bacon'}
E Full diff:
E - {1: 'spam', 2: 'bacon'}
E ? ^^^^^
E + {1: 'spam', 2: 'eggs'}
E ? ^^^^
""",
id="Compare dicts with differing values",
),
pytest.param(
"""
def test_this():
result = {1: 'spam', 2: 'eggs'}
expected = {1: 'spam', 3: 'bacon'}
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert {1: 'spam', 2: 'eggs'} == {1: 'spam', 3: 'bacon'}
E Common items:
E {1: 'spam'}
E Left contains 1 more item:
E {2: 'eggs'}
E Right contains 1 more item:
E {3: 'bacon'}
E Full diff:
E - {1: 'spam', 3: 'bacon'}
E ? ^ ^^^^^
E + {1: 'spam', 2: 'eggs'}
E ? ^ ^^^^
""",
id="Compare dicts with differing items",
),
pytest.param(
"""
def test_this():
result = "spmaeggs"
expected = "spameggs"
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert 'spmaeggs' == 'spameggs'
E - spameggs
E ? -
E + spmaeggs
E ? +
""",
id="Compare strings",
),
pytest.param(
"""
def test_this():
result = "spam bacon eggs"
assert "bacon" not in result
""",
"""
> assert "bacon" not in result
E AssertionError: assert 'bacon' not in 'spam bacon eggs'
E 'bacon' is contained here:
E spam bacon eggs
E ? +++++
""",
id='Test "not in" string',
),
]
if sys.version_info[:2] >= (3, 7):
TESTCASES.extend(
[
pytest.param(
"""
from dataclasses import dataclass
@dataclass
class A:
a: int
b: str
def test_this():
result = A(1, 'spam')
expected = A(2, 'spam')
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert A(a=1, b='spam') == A(a=2, b='spam')
E Matching attributes:
E ['b']
E Differing attributes:
E ['a']
E Drill down into differing attribute a:
E a: 1 != 2
E +1
E -2
""",
id="Compare data classes",
),
pytest.param(
"""
import attr
@attr.s(auto_attribs=True)
class A:
a: int
b: str
def test_this():
result = A(1, 'spam')
expected = A(1, 'eggs')
assert result == expected
""",
"""
> assert result == expected
E AssertionError: assert A(a=1, b='spam') == A(a=1, b='eggs')
E Matching attributes:
E ['a']
E Differing attributes:
E ['b']
E Drill down into differing attribute b:
E b: 'spam' != 'eggs'
E - eggs
E + spam
""",
id="Compare attrs classes",
),
]
)
@pytest.mark.parametrize("code, expected", TESTCASES)
def test_error_diff(code: str, expected: str, pytester: Pytester) -> None:
expected_lines = [line.lstrip() for line in expected.splitlines()]
p = pytester.makepyfile(code)
result = pytester.runpytest(p, "-vv")
result.stdout.fnmatch_lines(expected_lines)
assert result.ret == 1