Improve testing (#482)

* Adjust assert_conequal() to have a no strict mode

* Add test

* Add release notes

* Remove misleading return

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove unintentional runner

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Fabian Hofmann <fab.hof@gmx.de>

Author: 3 people

doc/release_notes.rst

@@ -3,6 +3,7 @@ Release Notes
 
 .. Upcoming Version
 .. ----------------
+.. * Improved constraint equality check in `linopy.testing.assert_conequal` to less strict optionally
 
 Version 0.5.6
 --------------

linopy/testing.py

@@ -29,9 +29,25 @@ def assert_quadequal(
     return assert_equal(_expr_unwrap(a), _expr_unwrap(b))
 
 
-def assert_conequal(a: Constraint, b: Constraint) -> None:
-    """Assert that two constraints are equal."""
-    return assert_equal(_con_unwrap(a), _con_unwrap(b))
+def assert_conequal(a: Constraint, b: Constraint, strict: bool = True) -> None:
+    """
+    Assert that two constraints are equal.
+
+    Parameters
+    ----------
+        a: Constraint
+            The first constraint.
+        b: Constraint
+            The second constraint.
+        strict: bool
+            Whether to compare the constraints strictly. If not, only compare mathematically relevant parts.
+    """
+    if strict:
+        assert_equal(_con_unwrap(a), _con_unwrap(b))
+    else:
+        assert_linequal(a.lhs, b.lhs)
+        assert_equal(a.sign, b.sign)
+        assert_equal(a.rhs, b.rhs)
 
 
 def assert_model_equal(a: Model, b: Model) -> None:

test/test_constraints.py

@@ -42,6 +42,31 @@ def test_constraint_assignment() -> None:
     assert_conequal(m.constraints.con0, con0)
 
 
+def test_constraint_equality() -> None:
+    m: Model = Model()
+
+    lower: xr.DataArray = xr.DataArray(
+        np.zeros((10, 10)), coords=[range(10), range(10)]
+    )
+    upper: xr.DataArray = xr.DataArray(np.ones((10, 10)), coords=[range(10), range(10)])
+    x = m.add_variables(lower, upper, name="x")
+    y = m.add_variables(name="y")
+
+    con0 = m.add_constraints(1 * x + 10 * y, EQUAL, 0)
+
+    assert_conequal(con0, 1 * x + 10 * y == 0, strict=False)
+    assert_conequal(1 * x + 10 * y == 0, 1 * x + 10 * y == 0, strict=False)
+
+    with pytest.raises(AssertionError):
+        assert_conequal(con0, 1 * x + 10 * y <= 0, strict=False)
+
+    with pytest.raises(AssertionError):
+        assert_conequal(con0, 1 * x + 10 * y >= 0, strict=False)
+
+    with pytest.raises(AssertionError):
+        assert_conequal(10 * y + 2 * x == 0, 1 * x + 10 * y == 0, strict=False)
+
+
 def test_constraints_getattr_formatted() -> None:
     m: Model = Model()
     x = m.add_variables(0, 10, name="x")