Add folding unit tests

Author: dflook

test/test_folding.py

@@ -0,0 +1,136 @@
+import ast
+import pytest
+
+from python_minifier import add_namespace
+from python_minifier.transforms.constant_folding import FoldConstants
+from python_minifier.ast_compare import compare_ast
+
+
+def fold_constants(source):
+    module = ast.parse(source)
+    add_namespace(module)
+    FoldConstants()(module)
+    return module
+
+
+@pytest.mark.parametrize('source,expected', [
+    ('True | True', 'True'),
+    ('True | False', 'True'),
+    ('False | True', 'True'),
+    ('False | False', 'False'),
+    ('True & True', 'True'),
+    ('True & False', 'False'),
+    ('False & True', 'False'),
+    ('False & False', 'False'),
+    ('True ^ True', 'False'),
+    ('True ^ False', 'True'),
+    ('False ^ True', 'True'),
+    ('False ^ False', 'False'),
+    ('(True | True) | True', 'True'),
+    ('(True | True) | False', 'True'),
+    ('(True | False) | True', 'True'),
+    ('(True | False) | False', 'True'),
+    ('(False | True) | True', 'True'),
+    ('(False | True) | False', 'True'),
+    ('(False | False) | True', 'True'),
+    ('(False | False) | False', 'False'),
+    ('(True | True) & True', 'True'),
+    ('(True | True) & False', 'False'),
+    ('(True | False) & True', 'True'),
+    ('(True | False) & False', 'False'),
+    ('(False | True) & True', 'True'),
+    ('(False | True) & False', 'False'),
+    ('(False | False) & True', 'False'),
+    ('(False | False) & False', 'False'),
+    ('(True | True) ^ True', 'False'),
+    ('(True | True) ^ False', 'True'),
+    ('(True | False) ^ True', 'False'),
+    ('(True | False) ^ False', 'True'),
+    ('(False | True) ^ True', 'False'),
+    ('(False | True) ^ False', 'True'),
+    ('(False | False) ^ True', 'True'),
+    ('(False | False) ^ False', 'False'),
+    ('True | (True | True)', 'True'),
+    ('True | (True | False)', 'True'),
+    ('True | (False | True)', 'True'),
+    ('True | (False | False)', 'True'),
+    ('False | (True | True)', 'True'),
+    ('False | (True | False)', 'True'),
+    ('False | (False | True)', 'True'),
+    ('False | (False | False)', 'False'),
+])
+def test_bool(source, expected):
+    """
+    Test BinOp with bool operands
+
+    This is mainly testing we fold the constants correctly
+    """
+    expected_ast = ast.parse(expected)
+    actual_ast = fold_constants(
+        source
+    )
+    compare_ast(expected_ast, actual_ast)
+
+@pytest.mark.parametrize('source,expected', [
+    ('10 + 10', '20'),
+    ('10 + 0', '10'),
+    ('0 + 10', '10'),
+    ('10 + 10 + 5', '25'),
+    ('10 - 5 + 5', '10'),
+    ('10 * 10', '100'),
+    ('10 * 10 * 10', '1000'),
+    ('(10 * 10) // 10', '10'),
+    ('(2 * 10) // (2+2)', '5'),
+    ('8>>2', '2'),
+    ('8<<2', '32'),
+    ('0xff^0x0f', '0xf0'),
+    ('0xf0&0xff', '0xf0'),
+    ('0xf0|0x0f', '0xff'),
+    ('10%2', '0'),
+    ('10%3', '1'),
+])
+def test_int(source, expected):
+    """
+    Test BinOp with integer operands we can fold
+    """
+    expected_ast = ast.parse(expected)
+    actual_ast = fold_constants(
+        source
+    )
+    compare_ast(expected_ast, actual_ast)
+
+@pytest.mark.parametrize('source,expected', [
+    ('10/10', '10/10'),
+    ('5+5/10', '5+5/10'),
+    ('2*5/10', '10/10'),
+    ('2/5*10', '2/5*10'),
+    ('2**5', '2**5'),
+    ('5@6', '5@6'),
+])
+def test_int_not_eval(source, expected):
+    """
+    Test BinOp with operations we don't want to fold
+    """
+    expected_ast = ast.parse(expected)
+    actual_ast = fold_constants(
+        source
+    )
+    compare_ast(expected_ast, actual_ast)
+
+@pytest.mark.parametrize('source,expected', [
+    ('"Hello" + "World"', '"Hello" + "World"'),
+    ('"Hello" * 5', '"Hello" * 5'),
+    ('b"Hello" + b"World"', 'b"Hello" + b"World"'),
+    ('b"Hello" * 5', 'b"Hello" * 5'),
+
+])
+def test_not_eval(source, expected):
+    """
+    Test BinOps we don't want to fold
+    """
+    expected_ast = ast.parse(expected)
+    actual_ast = fold_constants(
+        source
+    )
+    compare_ast(expected_ast, actual_ast)
+