From 8ed663cafde42cbe2e0171cb19d2217e01676d20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89tienne=20Mollier?= <emollier@debian.org>
Date: Sun, 11 Aug 2024 08:58:48 +0200
Subject: [PATCH] b/t/test_codegen.py: fix 2.00000000000000 == 2
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In sympy 1.13.0, symbolic representation differentiates between
integers and floats.  See [sympy merge request 25614] for further
details.  This results in a test case failure in test_codegen.py's
test_automatic_augmented_assignments when checking that there is no
formal difference between "x = x + x" and "x *= 2.0":

	_____________________ test_automatic_augmented_assignments _____________________

	    @pytest.mark.codegen_independent
	    def test_automatic_augmented_assignments():
	        # We test that statements that could be rewritten as augmented assignments
	        # are correctly rewritten (using sympy to test for symbolic equality)
	        variables = {
	            "x": ArrayVariable("x", owner=None, size=10, device=device),
	            "y": ArrayVariable("y", owner=None, size=10, device=device),
	            "z": ArrayVariable("y", owner=None, size=10, device=device),
	            "b": ArrayVariable("b", owner=None, size=10, dtype=bool, device=device),
	            "clip": DEFAULT_FUNCTIONS["clip"],
	            "inf": DEFAULT_CONSTANTS["inf"],
	        }
	        statements = [
	            # examples that should be rewritten
	            # Note that using our approach, we will never get -= or /= but always
	            # the equivalent += or *= statements
	            ("x = x + 1.0", "x += 1.0"),
	            ("x = 2.0 * x", "x *= 2.0"),
	            ("x = x - 3.0", "x += -3.0"),
	            ("x = x/2.0", "x *= 0.5"),
	            ("x = y + (x + 1.0)", "x += y + 1.0"),
	            ("x = x + x", "x *= 2.0"),
	            ("x = x + y + z", "x += y + z"),
	            ("x = x + y + z", "x += y + z"),
	            # examples that should not be rewritten
	            ("x = 1.0/x", "x = 1.0/x"),
	            ("x = 1.0", "x = 1.0"),
	            ("x = 2.0*(x + 1.0)", "x = 2.0*(x + 1.0)"),
	            ("x = clip(x + y, 0.0, inf)", "x = clip(x + y, 0.0, inf)"),
	            ("b = b or False", "b = b or False"),
	        ]
	        for orig, rewritten in statements:
	            scalar, vector = make_statements(orig, variables, np.float32)
	            try:  # we augment the assertion error with the original statement
	                assert (
	                    len(scalar) == 0
	                ), f"Did not expect any scalar statements but got {str(scalar)}"
	                assert (
	                    len(vector) == 1
	                ), f"Did expect a single statement but got {str(vector)}"
	                statement = vector[0]
	                expected_var, expected_op, expected_expr, _ = parse_statement(rewritten)
	                assert (
	                    expected_var == statement.var
	                ), f"expected write to variable {expected_var}, not to {statement.var}"
	                assert (
	                    expected_op == statement.op
	                ), f"expected operation {expected_op}, not {statement.op}"
	                # Compare the two expressions using sympy to allow for different order etc.
	                sympy_expected = str_to_sympy(expected_expr)
	                sympy_actual = str_to_sympy(statement.expr)
	>               assert sympy_expected == sympy_actual, (
	                    f"RHS expressions '{sympy_to_str(sympy_expected)}' and"
	                    f" '{sympy_to_str(sympy_actual)}' are not identical"
	                )
	E               AssertionError: RHS expressions '2.00000000000000' and '2' are not identical
	E               assert 2.00000000000000 == 2

	../debian/tmp/usr/lib/python3.12/dist-packages/brian2/tests/test_codegen.py:483: AssertionError

Checking against "x *= 2" resolves the issue, but it may make the test
incompatible with earlier sympy versions, so maybe there is some
version check or a more generic test to implement in case a larger
version coverage is needed.

[sympy merge request 25614]: https://github.com/sympy/sympy/pull/25614

Signed-off-by: Étienne Mollier <emollier@debian.org>
---
 brian2/tests/test_codegen.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/brian2/tests/test_codegen.py b/brian2/tests/test_codegen.py
index 1a3f1def8..fdc03cdf2 100644
--- a/brian2/tests/test_codegen.py
+++ b/brian2/tests/test_codegen.py
@@ -450,7 +450,7 @@ def test_automatic_augmented_assignments():
         ("x = x - 3.0", "x += -3.0"),
         ("x = x/2.0", "x *= 0.5"),
         ("x = y + (x + 1.0)", "x += y + 1.0"),
-        ("x = x + x", "x *= 2.0"),
+        ("x = x + x", "x *= 2"),
         ("x = x + y + z", "x += y + z"),
         ("x = x + y + z", "x += y + z"),
         # examples that should not be rewritten