go.starlark.net@v0.0.0-20231101134539-556fd59b42f6/starlark/testdata/bool.star (about)

     1  # Tests of Starlark 'bool'
     2  
     3  load("assert.star", "assert")
     4  
     5  # truth
     6  assert.true(True)
     7  assert.true(not False)
     8  assert.true(not not True)
     9  assert.true(not not 1 >= 1)
    10  
    11  # precedence of not
    12  assert.true(not not 2 > 1)
    13  # assert.true(not (not 2) > 1)   # TODO(adonovan): fix: gives error for False > 1.
    14  # assert.true(not ((not 2) > 1)) # TODO(adonovan): fix
    15  # assert.true(not ((not (not 2)) > 1)) # TODO(adonovan): fix
    16  # assert.true(not not not (2 > 1))
    17  
    18  # bool conversion
    19  assert.eq(
    20      [bool(), bool(1), bool(0), bool("hello"), bool("")],
    21      [False, True, False, True, False],
    22  )
    23  
    24  # comparison
    25  assert.true(None == None)
    26  assert.true(None != False)
    27  assert.true(None != True)
    28  assert.eq(1 == 1, True)
    29  assert.eq(1 == 2, False)
    30  assert.true(False == False)
    31  assert.true(True == True)
    32  
    33  # ordered comparison
    34  assert.true(False < True)
    35  assert.true(False <= True)
    36  assert.true(False <= False)
    37  assert.true(True > False)
    38  assert.true(True >= False)
    39  assert.true(True >= True)
    40  
    41  # conditional expression
    42  assert.eq(1 if 3 > 2 else 0, 1)
    43  assert.eq(1 if "foo" else 0, 1)
    44  assert.eq(1 if "" else 0, 0)
    45  
    46  # short-circuit evaluation of 'and' and 'or':
    47  # 'or' yields the first true operand, or the last if all are false.
    48  assert.eq(0 or "" or [] or 0, 0)
    49  assert.eq(0 or "" or [] or 123 or 1 // 0, 123)
    50  assert.fails(lambda : 0 or "" or [] or 0 or 1 // 0, "division by zero")
    51  
    52  # 'and' yields the first false operand, or the last if all are true.
    53  assert.eq(1 and "a" and [1] and 123, 123)
    54  assert.eq(1 and "a" and [1] and 0 and 1 // 0, 0)
    55  assert.fails(lambda : 1 and "a" and [1] and 123 and 1 // 0, "division by zero")
    56  
    57  # Built-ins that want a bool want an actual bool, not a truth value.
    58  # See github.com/bazelbuild/starlark/issues/30
    59  assert.eq(''.splitlines(True), [])
    60  assert.fails(lambda: ''.splitlines(1), 'got int, want bool')
    61  assert.fails(lambda: ''.splitlines("hello"), 'got string, want bool')
    62  assert.fails(lambda: ''.splitlines(0.0), 'got float, want bool')