Assertion in Python using Assertpy

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admin Posted on 01/08/2019

Assertpy is a simple assertion library in python with a nice fluent API. All automation testing validations should be asserted. In Java, we use AssertJ to compare actual and expected result. However, Assertpy is a suitable package to write readable assertions with method chaining concept. Implementing BDD step definitions using Assertpy enables effective collaboration between testers and other stakeholders. Writing chaining method calls for assertion helps automation testers to understand the existing test scripts during maintenance.

Installation

pip install assertpy

Matching strings

assert_that('').is_not_none()
assert_that('').is_empty()
assert_that('').is_false()
assert_that('').is_type_of(str)
assert_that('').is_instance_of(str)

assert_that('foo').is_length(3)
assert_that('foo').is_not_empty()
assert_that('foo').is_true()
assert_that('foo').is_alpha()
assert_that('123').is_digit()
assert_that('foo').is_lower()
assert_that('FOO').is_upper()
assert_that('foo').is_iterable()
assert_that('foo').is_equal_to('foo')
assert_that('foo').is_not_equal_to('bar')
assert_that('foo').is_equal_to_ignoring_case('FOO')

assert_that(u'foo').is_unicode() # on python 2
assert_that('foo').is_unicode()  # on python 3

assert_that('foo').contains('f')
assert_that('foo').contains('f','oo')
assert_that('foo').contains_ignoring_case('F','oO')
assert_that('foo').does_not_contain('x')
assert_that('foo').contains_only('f','o')
assert_that('foo').contains_sequence('o','o')

assert_that('foo').contains_duplicates()
assert_that('fox').does_not_contain_duplicates()

assert_that('foo').is_in('foo','bar','baz')
assert_that('foo').is_not_in('boo','bar','baz')
assert_that('foo').is_subset_of('abcdefghijklmnopqrstuvwxyz')

assert_that('foo').starts_with('f')
assert_that('foo').ends_with('oo')

assert_that('foo').matches(r'w')
assert_that('123-456-7890').matches(r'd{3}-d{3}-d{4}')
assert_that('foo').does_not_match(r'd+')

Matching Integers

assert_that(0).is_not_none()
assert_that(0).is_false()
assert_that(0).is_type_of(int)
assert_that(0).is_instance_of(int)

assert_that(0).is_zero()
assert_that(1).is_not_zero()
assert_that(1).is_positive()
assert_that(-1).is_negative()

assert_that(123).is_equal_to(123)
assert_that(123).is_not_equal_to(456)

assert_that(123).is_greater_than(100)
assert_that(123).is_greater_than_or_equal_to(123)
assert_that(123).is_less_than(200)
assert_that(123).is_less_than_or_equal_to(200)
assert_that(123).is_between(100, 200)
assert_that(123).is_close_to(100, 25)

assert_that(1).is_in(0,1,2,3)
assert_that(1).is_not_in(-1,-2,-3)