PicoTest 0.2.0

a small but very useful testing library for Python

Release: 0.2.0

Contents

• Overview

• Basic Example

• Test Structure

• Setup and Teadown Fixture

• Fixture Injection

• Skip and Todo

• Extened Assertion Methods

• Command-line Interface

• Copyright

• License

Overview

PicoTest.py is a small but very useful testing library for Python.

Basic Example

PicoTest.py uses with statement instead of TestCase class.

• Test topc or context is represented by with statement.

• Test spec is represented by @test decorator.

examples/1_basic_test.py:

import picotest
test = picotest.new()

with test("assertion example"):

    @test("1+1 should be 2")
    def _():                # 'self' is not required
        assert 1+1 == 2

    @test("assertion methods of unittest are avaiable")
    def _(self):
        self.assertEqual("Haruhi".upper(), "HARUHI")

    @test("'assertTextEqual()' is available which shows diff of two texts")
    def _(self):
        expected = "Haruhi\nMikuru\nYuki"
        actual   = "\n".join(["Haruhi", "Mikuru", "Yuki"])
        #actual   = "\n".join(["Haruhi", "Michiru", "Yuki"])
        self.assertTextEqual(expected, actual)

if __name__ == '__main__':
    picotest.main()

Output example (verbose style):

$ python examples/1_basic_test.py
* assertion example
  - [passed] 1+1 should be 2
  - [passed] assertion methods of unittest are avaiable
  - [passed] 'assertTextEqual()' is available which shows diff of two texts
----------------------------------------------------------------------
## total:3, passed:3, failed:0, error:0, skipped:0, todo:0

Output example (plain style):

$ python examples/1_basic_test.py -sp   # or -s plain
...
## total:3, passed:3, failed:0, error:0, skipped:0, todo:0

Test Structure

Nested test structure is available. This makes you to write tests in structured style.

examples/2_structure_test.py:

import picotest
test = picotest.new()

with test("ClassName"):

    with test("#method_name()"):

        with test("when base is not specified..."):

            @test("int('11') should be 11")
            def _():
                assert int('11') == 11

        with test("when base is specified..."):

            @test("int('11', 16) should be 17")
            def _():
                assert int('11', 16) == 17

            @test("int('11', 8) should be 9")
            def _():
                assert int('11', 8) == 9

            @test("int('11', 2) should be 3")
            def _():
                assert int('11', 2) == 3

if __name__ == '__main__':
    test.main()

Setup and Teadown Fixture

Setup and teardown fixtures are available. They are provided by decorators.

@test.before

Same as setUp(). Invoked before each test.

@test.after

Same as tearDown(). Invoked after each test.

@test.before_all

Similar to setUpClass(). Invoked only once before all tests.

@test.after_all

Similar to tearDownClass(). Invoked only once after all tests.

examples/3_setup_teadown_test.py:

import os
import picotest
test = picotest.new()

with test("fixtures (setup, teardown) example"):
    PWD = os.getcwd()

    @test.before_all   # setupAll
    def _():
        os.mkdir("_sandbox")
        os.chdir("_sandbox")

    @test.after_all    # afterAll
    def _():
        os.chdir(PWD)
        os.rmdir("_sandbox")

    @test.before       # setup
    def _(self):
        self.name = "Haruhi"
        self.team = "SOS"

    @test.after        # teardown
    def _(self):
        pass

    @test("fixture should be called #1")
    def _(self):
        self.assertEqual("Haruhi", self.name)

    @test("fixture should be called #2")
    def _(self):
        self.assertEqual("SOS", self.team)

if __name__ == '__main__':
    picotest.main()

Fixture Injection

Fixture Injection is available which is more flexible than setup/teardown.

examples/4_fixture_injection_test.py:

import os
import picotest
test = picotest.new()

with test("fixture injection example"):

    @test.fixture
    def member(self):
        yield "Haruhi"     # use 'yield', not 'return'

    @test.fixture
    def team():            # 'self' is optional
        yield "SOS"

    @test("fixture is injected automatically")
    def _(self, member, team):
        assert member == "Haruhi"
        assert team   == "SOS"

    @test.fixture
    def tmpfile(self):
        ## setup temporary file
        filename = "_tmpfile.txt"
        with open(filename, "w") as f: f.write("SOS\n")
        yield filename
        ## teardown temporary file
        os.unlink(filename)

    @test("temporary file is created and removed automatically")
    def _(tmpfile):
        assert tmpfile == "_tmpfile.txt"
        with open(tmpfile) as f:
            assert f.read() == "SOS\n"

if __name__ == '__main__':
    picotest.main()

Skip and Todo

PicoTest.py supports test skip and todo.

picotest.skip_when(condition, reason)

When condition is true then skip rest assertions.

picotest.todo

Decorator to represents that “feature is not implemented yet”.

test.TODO(description):

Same as:

@test("...description...")
@todo
def _():
    assert False     # expected failure

example/5_skip_and_todo_test.py:

import picotest
from picotest import skip_when, todo
test = picotest.new()

with test("skip and todo example"):

    @test("skip test when condition is true")
    def _(self):
        condition = True
        skip_when(condition, "REASON")
        assert 1 == 0     # unreachable

    @test("'@todo' means 'not implemented yet'")
    @todo
    def _(self):
        assert 1 == 0    # expected failure

    test.TODO("something what you have to do #1")
    test.TODO("something what you have to do #2")

if __name__ == '__main__':
    picotest.main()

Extened Assertion Methods

PicoTest.py adds some new assertion methods to unittest.TestCase class.

self.assertTextEqual(expected, actual)

Similar to assertEqual(), but diplays unified diff when actual and expected are different text. Equivarent to assertMultilineEqual() but available in Python 2.6 or older. Example:

expected = "Haruhi\nMikuru\nYuki\n"
actual   = "Haruhi\nMichiru\nYuki\n"
self.assertTextEqual(expected, actual)
## output:
# AssertionError: texts are not equal.
# --- expected
# +++ actual
# @@ -1,3 +1,3 @@
#  Haruhi
# -Mikuru
# +Michiru
#  Yuki

self.assertException(function, exceptionclass[, errormsg=None])

Similar to assertRaise(), but this can check error message. errormsg can be string or pattern object compiled by re.compile(). In addition, you can get exeption object as function.exception. Example:

def fn(): int("foo")
self.assertException(fn, ValueError, "invalid literal for int() with base 10: 'foo'")
## or
self.assertException(fn, ValueError, re.compile(r'^invalid literal'));
## or
self.assertException(fn, ValueError)
self.assertEqual("invalid literal for int() with base 10: 'foo'", str(fn.exception))

self.assertNotException(function[, exceptionclass=Exception])

Confirms that function doesn’t raise exception. Example:

def fn(): int("FF", 16)
self.assertNotException(fn)

Command-line Interface

PicoTest.py provides command-line interface:

$ python test/foo_test.py        # run test script (verbose style)
$ python test/foo_test.py -sp    # run test script (plain style)
$ python test/*.py               # run all test scripts
$ python -m picotest test/*.py   # run all test scripts
$ python -m picotest test        # run all under 'test' directory
$ python -m picotest -h                 # show help
$ python -m picotest -v                 # print version
$ python -m picotest -sv test/*.py      # or -s verbose
$ python -m picotest -ss test/*.py      # or -s simple
$ python -m picotest -sp test/*.py      # or -s plain
$ python -m picotest --test='...' test  # filter by description
$ python -m picotest -D test/*.py       # show all backtrace

picotest.main() exists process with status code which represens number of failed or error tests:

$ python examples/1_basic_test.py -sp
..f
----------------------------------------------------------------------
[Failed] assertion example > 'assertTextEqual()' is available which shows diff of two texts
   :
----------------------------------------------------------------------
## total:3, passed:2, failed:1, error:0, skipped:0, todo:0
$ echo $?
1                 # number of failed or error tests

Copyright

$Copyright: copyright(c) 2011 kuwata-lab.com all rights reserved $

License

$License: MIT License $