def test_comparison():
# reduce less than
result = optimize(parse("1 < 2 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce greater than
result = optimize(parse("2 > 1 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce less or equal
result = optimize(parse("1 <= 2 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce greater or equal
result = optimize(parse("2 >= 1 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce not equal
result = optimize(parse("2 <> 1 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
def test_in():
# allow reduction when the left hand side and all options
# are certain
result = optimize(parse("1 IN (1, 2, 3) AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
result = optimize(parse("5 NOT IN (1, 2, 3) AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# don't allow reduction if either left hand side or either option
# is uncertain
result = optimize(parse("attr IN (1, 2, 3)"))
assert result == ast.In(
ast.Attribute('attr'),
[1, 2, 3],
False
)
result = optimize(parse("1 IN (attr, 2, 3)"))
assert result == ast.In(
1,
[ast.Attribute('attr'), 2, 3],
False
)
def test_like():
# allow reduction
result = optimize(parse("'This is a test' LIKE 'This is %' AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
result = optimize(
parse("'This is a test' LIKE 'This is . test' AND attr = 1")
)
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# don't reduction when an attribute is referenced
result = optimize(parse("attr LIKE 'This is %'"))
assert result == ast.Like(
ast.Attribute('attr'),
'This is %',
False,
'%',
'.',
'\\',
False
)
def test_between():
# allow reduction
result = optimize(parse("5 BETWEEN 1 AND 6 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
result = optimize(parse("10 NOT BETWEEN 1 AND 6 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# don't reduce if either lhs, low or high are uncertain
result = optimize(parse("attr BETWEEN 1 AND 6"))
assert result == ast.Between(
ast.Attribute("attr"), 1, 6, False
)
result = optimize(parse("5 BETWEEN attr AND 6"))
assert result == ast.Between(
5, ast.Attribute("attr"), 6, False
)
result = optimize(parse("5 BETWEEN 1 AND attr"))
assert result == ast.Between(
5, 1, ast.Attribute("attr"), False
)
def test_arithmetic():
# test possible optimizations
result = optimize(parse("attr = 10 + 10"))
assert result == ast.Equal(
ast.Attribute('attr'),
20
)
result = optimize(parse("attr = 30 - 10"))
assert result == ast.Equal(
ast.Attribute('attr'),
20
)
result = optimize(parse("attr = 10 * 2"))
assert result == ast.Equal(
ast.Attribute('attr'),
20
)
result = optimize(parse("attr = 40 / 2"))
assert result == ast.Equal(
ast.Attribute('attr'),
20
)
# test imppossible optimizations
result = optimize(parse("attr = other + 10"))
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Add(
ast.Attribute('other'), 10
),
)
result = optimize(parse("attr = other - 10"))
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Sub(
ast.Attribute('other'), 10
),
)
result = optimize(parse("attr = other * 2"))
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Mul(
ast.Attribute('other'), 2
),
)
result = optimize(parse("attr = other / 2"))
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Div(
ast.Attribute('other'), 2
),
)
def test_function():
def myadder(a, b):
return a + b
result = optimize(parse("attr = myadder(1, 2)"), {"myadder": myadder})
assert result == ast.Equal(
ast.Attribute('attr'),
3,
)
# can't optimize a function referencing an attribute
result = optimize(parse("attr = myadder(other, 2)"), {"myadder": myadder})
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Function(
"myadder", [
ast.Attribute("other"),
2
]
)
)
# can't optimize a function with a nested reference to an attribute
result = optimize(
parse("attr = myadder(other + 2, 2)"), {"myadder": myadder}
)
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Function(
"myadder", [
ast.Add(ast.Attribute("other"), 2),
2
]
)
)
# can't optimize an unknown functions
result = optimize(parse("attr = unkown(1, 2)"), {"myadder": myadder})
assert result == ast.Equal(
ast.Attribute('attr'),
ast.Function(
"unkown", [
1,
2,
]
)
)
def test_combination():
# reduce right hand side
result = optimize(parse("attr = 1 AND 1 < 2"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce left hand side
result = optimize(parse("1 < 2 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# reduce left hand side
result = optimize(parse("1 < 2 AND attr = 1"))
assert result == ast.Equal(
ast.Attribute('attr'),
1
)
# can' reduce
result = optimize(parse("attr = 1 AND other = 2"))
assert result == ast.And(
ast.Equal(
ast.Attribute('attr'),
1
),
ast.Equal(
ast.Attribute('other'),
2
)
)
# reduce AND to an INCLUDE if both sides evaluate to true
result = optimize(parse("1 = 1 AND 2 = 2"))
assert result == ast.Include(False)
# reduce AND to an EXCLUDE if either side evaluates to false
result = optimize(parse("attr = 1 AND 2 = 3"))
assert result == ast.Include(True)
result = optimize(parse("2 = 3 AND attr = 1"))
assert result == ast.Include(True)
result = optimize(parse("0 = 1 AND 2 = 3"))
assert result == ast.Include(True)
# reduce OR to INCLUDE if either side evaluates to true
result = optimize(parse("attr = 1 OR 2 = 2"))
assert result == ast.Include(False)
result = optimize(parse("2 = 2 OR attr = 1"))
assert result == ast.Include(False)
# reduce OR to an EXCLUDE if both sides evaluate to false
result = optimize(parse("1 = 2 AND 2 = 1"))
assert result == ast.Include(True)
def test_not():
result = optimize(parse("NOT 1 > 2"))
assert result == ast.Include(False)
result = optimize(parse("NOT 1 < 2"))
assert result == ast.Include(True)