preggy

preggy 是一个 Python 的断言库。你期望什么？

来自 PyVows 项目。

安装

我们推荐使用 pip

pip install preggy

用法

简单告诉测试你期望的 expect()

from preggy import expect

def test_roses_are_red():
    rose = Rose()
    expect(rose.color).to_equal('red')

def test_violets_are_not_red():
    violet = Violet()
    expect(violet.color).not_to_equal('red')

内置期望

相等

expect(4).to_equal(4)
expect(5).Not.to_equal(4)
expect(5).not_to_equal(4)  # same as previous

比较

expect(4).to_be_lesser_than(5)
expect(5).to_be_greater_than(4)
expect(5).Not.to_be_lesser_than(4)
expect(4).not_to_be_greater(5)  # same as previous

expect(4).to_be_lesser_or_equal_to(5)
expect(4).to_be_lesser_or_equal_to(4)
expect(5).not_to_be_lesser_or_equal_to(4)

expect(5).to_be_greater_or_equal_to(4)
expect(5).to_be_greater_or_equal_to(5)
expect(4).not_to_be_greater_or_equal_to(5)

expect("b").to_be_greater_than("a")
expect("a").to_be_lesser_than("b")

expect([1, 2, 3]).to_be_greater_than([1, 2])  # comparing using length
expect((1, 2, 3)).to_be_greater_than((1, 2))  # comparing using length
expect({ "a": "b", "c": "d" }).to_be_greater_than({ "a": "b" })  # comparing using length of keys

相似性

expect('sOmE RandOm     CAse StRiNG').to_be_like('some random case string')

expect(1).to_be_like(1)
expect(1).to_be_like(1.0)
expect(1).to_be_like(long(1))

expect([1, 2, 3]).to_be_like([3, 2, 1])
expect([1, 2, 3]).to_be_like((3, 2, 1))
expect([[1, 2], [3,4]]).to_be_like([4, 3], [2, 1]])

expect({ 'some': 1, 'key': 2 }).to_be_like({ 'key': 2, 'some': 1 })

expect('sOmE RandOm     CAse StRiNG').Not.to_be_like('other string')
expect('sOmE RandOm     CAse StRiNG').not_to_be_like('other string')  # same as previous

expect(1).not_to_be_like(2)
expect([[1, 2], [3,4]]).not_to_be_like([4, 4], [2, 1]])
expect({ 'some': 1, 'key': 2 }).not_to_be_like({ 'key': 3, 'some': 4 })

类型

expect(os.path).to_be_a_function()
expect(1).to_be_numeric()
expect({ 'some': 1, 'key': 2 }).to_be_instance_of(dict)
expect(open(__file__)).to_be_a_file()

expect('some').Not.to_be_a_function()
expect('some').Not.to_be_numeric()
expect('some').Not.to_be_instance_of(dict)
expect('some').Not.to_be_a_file()

真 / 假

expect(True).to_be_true()
expect('some').to_be_true()
expect([1, 2, 3]).to_be_true()
expect({ 'a': 'b' }).to_be_true()
expect(1).to_be_true()

expect(False).to_be_false()  # not_to_be_true() would work, too. but, it's so...eww
expect(None).to_be_false()
expect('').to_be_false()
expect(0).to_be_false()
expect([]).to_be_false()
expect({}).to_be_false()

空值

expect(None).to_be_null()
expect('some').Not.to_be_null()
expect('some').not_to_be_null()  # same as previous

包含

expect([1, 2, 3]).to_include(2)
expect((1, 2, 3)).to_include(2)
expect('123').to_include('2')
expect({ 'a': 1, 'b': 2, 'c': 3}).to_include('b')

expect([1, 3]).Not.to_include(2)  # or, exclusion...

正则表达式

expect('some').to_match(r'^[a-z]+')
expect('Some').Not.to_match(r'^[a-z]+')

长度

expect([1, 2, 3]).to_length(3)
expect((1, 2, 3)).to_length(3)
expect('abc').to_length(3)
expect({ 'a': 1, 'b': 2, 'c': 3}).to_length(3)
expect(lifo_queue).to_length(2)
expect(queue).to_length(3)

expect([1]).Not.to_length(3)
expect([1]).not_to_length(3)  # same as previous

空

expect([]).to_be_empty()
expect(tuple()).to_be_empty()
expect({}).to_be_empty()
expect('').to_be_empty()

expect([1]).not_to_be_empty()
expect((1,2)).not_to_be_empty()
expect({'a': 1}).not_to_be_empty()
expect('roses are red').not_to_be_empty()

异常

expect(RuntimeError()).to_be_an_error() 
expect(RuntimeError()).to_be_an_error_like(RuntimeError)
expect(ValueError('error')).to_have_an_error_message_of('error')

expect("I'm not an error").Not.to_be_an_error()
expect(ValueError()).Not.to_be_an_error_like(RuntimeError)
expect(ValueError('some')).Not.to_have_an_error_message_of('error')

# when expecting a method to error
err = expect.error_to_happen(RuntimeError)  # attribute to a variable so you can use the exception later

with err:
    raise RuntimeError("something is wrong")

expect(err).to_have_an_error_message_of('something is wrong')

# or the shorter version
with expect.error_to_happen(RuntimeError, message="something is wrong"):
    raise RuntimeError("something is wrong")

# or if you don't care about the message:
with expect.error_to_happen(RuntimeError):
    raise RuntimeError("something is wrong")

# or if you need to make sure error does not happen
with expect.error_not_to_happen(RuntimeError, message="something is wrong"):
    raise RuntimeError("something is wrong")  # Fails with AssertionError

# or if you don't care about the message, only that the error does not happen:
with expect.error_not_to_happen(RuntimeError):
    raise RuntimeError("something is wrong")  # Fails with AssertionError

失败

expect.not_to_be_here()  # raises AssertionError

# raises AssertionError with error message
expect.not_to_be_here("some error message")

链式断言

# assertions may be chained, for brevity:
expect(6).not_to_be_null().to_equal(6)

# a more *sensible* example:
expect(foo).not_to_be_null().to_equal(expected.get('foo'))

贡献

查看 CONTRIBUTING。

许可协议

MIT 许可证 (MIT)

版权所有 (c) 2013 Bernardo Heynemann heynemann@gmail.com

在此特此授予任何获得此软件及其相关文档副本（“软件”）的人免费使用软件的权利，不受限制地处理软件，包括但不限于使用、复制、修改、合并、发布、分发、再许可和/或销售软件副本，并允许向软件提供方提供软件的人这样做，但受以下条件约束

上述版权声明和本许可声明应包含在软件的任何副本或主要部分中。

本软件按“原样”提供，不提供任何形式的保证，无论是明示的还是暗示的，包括但不限于适销性、特定用途的适用性和非侵权性。在任何情况下，作者或版权所有者均不对任何索赔、损害或其他责任负责，无论这些责任是因合同、侵权或其他原因而产生的，无论这些责任是否与软件或软件的使用或其他方式有关。