TDD Con Python

Test-Driven Developmentcon Python

y un ejemplo: la librería algoritmia

Andrés MarzalDepartamento de Lenguajes y Sistemas Informáticos

Universitat Jaume [email protected]

viernes 9 de abril de 2010



”

“If you look at how most programmers spend their time, you’ll find that writing code is actually a small fraction. Some time is spent figuring out what ought to be going on, some time is spent designing, but most time is spent debugging. I’m sure every reader can remember long hours of debugging, often long into the night. Every programmer can tell a story of a bug that took a whole day (or more) to find. Fixing the bug is usually pretty quick, but finding it is a nightmare. And then when you do fix a bug, there’s always a chance that another one will appear and that you might not even notice it until much later. Then you spend ages finding that bug.

Martin Fowler


• ¿Qué es TDD?

• ¿Con qué herramientas hacemos TDD con Python?

• Una demo

• unitest

• mockito

• coverage

• Algunas conclusiones

• Algoritmia

Guión


¿Qué es TDD?


Desarrollo Tradicional


Desarrollo TradicionalUnified

ModelingLanguage(UML)

RationalUnifiedProcess(RUP)

CapabilityMaturityModel(CMM)Big Design

Up-Front(BDUF)

Desarrolloen Cascada

COCOMO


Desarrollo Tradicional


2001viernes 9 de abril de 2010

Mike Beedle

Arie van Bennekum

Alistair Cockburn

Ward Cunningham

Martin FowlerJim Highsmith

Andy Hunt

Ron Jeffries

Jon Kern

Brian Marick

Robert C. MartinUncle Bob

Ken Schwaber

Jeff Sutherland

Dave Thomas


XP Programming

Scrum

Kanbanviernes 9 de abril de 2010

Manifesto for Agile Software Development



Individuals and interactions over processes and tools




Working software over comprehensive documentation





Customer collaboration over contract negotiation






Responding to change over following a plan







That is, while there is value in the items on the right, we value the items on the left more.







That is, while there is value in the items on the right, we value the items on the left more.

http://agilemanifesto.org


Desarrollo ágil

• Programación por parejas

• Historias de usuario

• La metáfora del sistema

• Clientes in situ

• Unidades de prueba

• Desarrollo dirigido por pruebas

• Refactorización

• Diseño simple

• Iteraciones cortas

• Propiedad colectiva del código

• Reflexión continua

• Integración continua


¿Qué es una prueba unitaria?

• Una unidad de prueba (unit test) es un trozo de código (típicamente un método) que invoca a otro trozo de código y comprueba después la corrección de algunas asunciones.

• Si las asunciones no eran válidas, se dice que la unidad de prueba ha fallado.

• Una unidad (unit) es un método o función.


El sistema a prueba

• El sistema sometido a prueba (system under test) recibe el nombre de SUT.

• Hay quien llama CUT a la clase sometida a prueba.


No confundir

• Prueba de aceptación: el programa supera una demanda del cliente

• Prueba de integración

• Prueba de regresión

• Prueba de prestaciones

• Prueba de carga

• Prueba de estrés


Buenos “unit test”

• Automatizable y repetible

• Fácil de implementar

• Debe permanecer, una vez se ha escrito

• Cualquiera debe poder ejecutarlo

• Ejecutarlo debe ser sencillo

• Debe ser rápido


Frameworks

• Los frameworks de unit testing permiten:

• Simplificar el diseño de pruebas unitarias

• Facilitar un entorno para la ejecución de las pruebas

• Proporcionar informes de los resultados


Frameworks

• xUnit:

• JUnit: Java

• NUnit: C#

• PyUnit: Python

• Test::Unit: Ruby

• ...


The various meanings of TDD

• 1) Test Driven Development: the idea of writing your code in a test first manner. You may already have an existing design in place.

• 2) Test Oriented Development: Having unit tests of integration tests in your code and write them out either before or after our write the code. Your code has lots of tests. You recognize the value of tests but you don't necessarily write them before you write the code. Design probably exists before you write the code

• 3) Test Driven Design(the eXtreme Programming way): The idea of using a test-first approach as a fully fledged design technique, where tests are a bonus but the idea is to drive full design from little to no design whatsoever. You design as you go.

• 4) Test Driven Development and Design: using the test-first technique to drive new code and changes, while also allowing it to change and evolve your design as an added bonus. You may already have some design in place before starting to code, but it could very well change because the tests point out various smells.

http://weblogs.asp.net/rosherove/archive/2007/10/08/the-various-meanings-of-tdd.aspx





Desarrollo dirigido por las pruebas (TDD)


More NUnit attributes 39

!"#$%&'()*' In NUnit, an ignored test is marked in yellow (the middle test), and the reason for not running the test is listed under the Tests Not Run tab on the right.

It can look like this:

[Test][Ignore("there is a problem with this test")] public void IsValidFileName_ValidFile_ReturnsTrue() { /// ... }

Running this test in the NUnit GUI will produce a result like that shown in figure 2.6.

What happens when you want to have tests running not by a namespace but by some other type of grouping? That’s where test cate-gories come in.

()+), -&.."/#'.&0.'12.&#3%"&0

You can set up your tests to run under specific test categories, such as slow tests and fast tests. You do this by using NUnit’s [Category] attri-bute:

[Test][Category("Fast Tests")] public void IsValidFileName_ValidFile_ReturnsTrue() { /// ... }


¿Con qué herramientas hacemos TDD con

Python?


Python

• Versión 3.1.2

• http://www.python.org


http://www.python.org

http://www.python.org

unittest (PyUnit)

• Viene de serie con Python 3.1


Eclipse

• Versión 3.5.2, Galileo

• http://eclipse.org


http://eclipse.org

http://eclipse.org

• Versión 1.5.6

• http://pydev.org

• Instalación: http://pydev.org/updates


http://pydev.org

http://pydev.org

http://pydev.org/updates

http://pydev.org/updates

Pydev


Una demo


Sudoku

• Queremos un programa que permita jugar a Sudokus

• En aras de la brevedad, Sudokus de 4x4


Historias de usuario

1. Dada una lista con 4 filas de números, saber si describe un Sudoku de 4x4

2. Dada una cadena con 4 líneas de caracteres entre 1 y 4 y asteriscos en posición libre, obtener las lista que lo describe

3. Resolver automáticamente un Sudoku

4. Jugar partidas contra un jugador humano


Creación de un proyecto Pydev

• File:: New:: Pydev project



Asociar una gramática Python e intérprete

• Menu contextual del proyecto

• Properties

• PyDev - Interpreter/Grammar

• Configurar un intérprete


Fijar perspectiva Pydev

• Open Perspective :: Other... ::


Empezamos

• Ye hemos creado el proyecto Sudoku

• Contendrá una carpeta src

• Dentro creamos un package para las pruebas (menú contextual en el proyecto: New :: Pydev package) y le llamamos test








Pruebas de aceptación1. Dada una lista con 4 filas de números, saber si describe un

Sudoku de 4x4

1.1. Rechaza una “no lista”

1.2. Rechaza lista que no es de 4x4

1.3. Rechaza lista que no contiene 4x4 enteros

1.4. Se suministra una lista de 4x4 con números menores que 0 o mayores que 4 y la rechaza

1.5. Rechaza lista con repetidos en fila

1.6. Rechaza lista con repetidos en columna

1.7. Rechaza lista con repetidos en región 2x2


• Dentro creamos un package para las pruebas (menú contextual en el proyecto: New :: Pydev package) y le llamamos test

• En test creamos un módulo Python de tipo Unittest: test_SudokuValidator

• Y creamos el primer ¿método de test?

Manos a la obra


'''Created on 06/04/2010

@author: amarzal'''import unittest

class Test(unittest.TestCase):

def testName(self): pass

if __name__ == "__main__": #import sys;sys.argv = ['', 'Test.testName'] unittest.main()


from unittest import TestCase

class TestSudokuValidator(TestCase): def test_sudoku_isNotAList_isRejected(self): validator = SudokuValidator() sudoku = 0 self.assertFalse(validator.check(sudoku), "Acepta una no lista")




TestCase: Clase cuyos métodos son

tests





tests

Método de test: empieza por test_





tests


SUT





tests


SUT

Aserto





tests


SUT

Aserto Mensaje de fallo


¿Pasa la prueba?

• Evidentemente, no puede pasarlo. El SUT no existe aún.

• Pero veamos cómo falla:

• Menú contextual en test_SudokuValidator.py, Run As :: Python unit-test_SudokuValidator.py


Finding files...['/Users/amarzal/Documents/workspace/Sudoku/src/tests/test_SudokuValidator.py'] ... doneImporting test modules ... done.

test_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator) ... ERROR

======================================================================ERROR: test_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator)----------------------------------------------------------------------Traceback (most recent call last): File "/Users/amarzal/Documents/workspace/Sudoku/src/tests/test_SudokuValidator.py", line 7, in test_sudoku_isNotAList_isRejected validator = SudokuValidator()NameError: global name 'SudokuValidator' is not defined

----------------------------------------------------------------------Ran 1 test in 0.001s

FAILED (errors=1)


A por el SUT• En src creamos un package: sudoku

• En el package creamos un módulo: validator

• En ese módulo definimos la clase SudokuValidator con el método check

class SudokuValidator: def check(self, sudoku): if not isinstance(sudoku, list): return False return True


from unittest import TestCasefrom sudoku.validator import SudokuValidator




test_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator) ... ok

----------------------------------------------------------------------Ran 1 test in 0.000s

OK


Tests de aceptación1. Dada una lista con 4 filas de números, saber si describe un

Sudoku de 4x4










class TestSudokuValidator(TestCase): def test_sudoku_isNotAList_isRejected(self): validator = SudokuValidator() sudoku = 0 self.assertFalse(validator.check(sudoku)) def test_sudoku_isNotA4x4List_isRejected(self): validator = SudokuValidator() sudoku = [] self.assertFalse(validator.check(sudoku))

Los mensajes pueden ser superfluos si se

nombran bien los test



test_sudoku_isNotA4x4List_isRejected (test_SudokuValidator.TestSudokuValidator) ... FAILtest_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator) ... ok

======================================================================FAIL: test_sudoku_isNotA4x4List_isRejected (test_SudokuValidator.TestSudokuValidator)----------------------------------------------------------------------Traceback (most recent call last): File "/Users/amarzal/Documents/workspace/Sudoku/src/tests/test_SudokuValidator.py", line 15, in test_sudoku_isNotA4x4List_isRejected self.assertFalse(validator.check(sudoku))AssertionError: True is not False

----------------------------------------------------------------------Ran 2 tests in 0.001s

FAILED (failures=1)


class SudokuValidator: def check(self, sudoku): if not isinstance(sudoku, list): return False

if len(sudoku) != 4: return False for row in sudoku: if not isinstance(sudoku, list): return False if len(row) != 4: return False

return Trueviernes 9 de abril de 2010


test_sudoku_isNotA4x4List_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator) ... ok

----------------------------------------------------------------------Ran 2 tests in 0.000s

OK



class TestSudokuValidator(TestCase): def test_sudoku_isNotAList_isRejected(self): validator = SudokuValidator() sudoku = 0 self.assertFalse(validator.check(sudoku)) def test_sudoku_isNotA4x4List_isRejected(self): validator = SudokuValidator() sudoku = [] self.assertFalse(validator.check(sudoku))



class TestSudokuValidator(TestCase):

def setUp(self): self.validator = SudokuValidator() def test_sudoku_isNotAList_isRejected(self): sudoku = 0 self.assertFalse(self.validator.check(sudoku)) def test_sudoku_isNotA4x4List_isRejected(self): sudoku = [] self.assertFalse(self.validator.check(sudoku))


Tests de aceptación1. Dada una lista con 4 filas de números, saber si describe un

Sudoku de 4x4









class SudokuValidator: def check(self, sudoku): if not isinstance(sudoku, list): return False if len(sudoku) != 4: return False for row in sudoku: if not isinstance(sudoku, list): return False if len(row) != 4: return False for row in sudoku: for number in row: if not isinstance(number, int): return False for row in sudoku: for number in row: if not (0 <= number <= 4): return False

for i in range(4): numbers = set() for j in range(4): n = sudoku[i][j] if n != 0 and n in numbers: return False numbers.add(n) for j in range(4): numbers = set() for i in range(4): n = sudoku[i][j] if n != 0 and n in numbers: return False numbers.add(n) for region in (((0,0), (0,1), (1,0), (1,1)), ((0,2), (0,3), (1,2), (1,3)), ((2,0), (2,1), (3,0), (3,1)), ((2,2), (2,3), (3,2), (3,3))): numbers = set() for (i, j) in region: n = sudoku[i][j] if n != 0 and n in numbers: return False numbers.add(n) return True


¡Hora de refactorizar!

• Pero ya no saltamos sin red:

podemos refactorizar con la tranquilidad de que los tests “nos vigilan”


class SudokuValidator: def __init__(self): rows = tuple(tuple((i, j) for j in range(4)) for i in range(4)) columns = tuple(tuple((i, j) for i in range(4)) for j in range(4)) sectors = (((0,0), (0,1), (1,0), (1,1)), ((0,2), (0,3), (1,2), (1,3)), ((2,0), (2,1), (3,0), (3,1)), ((2,2), (2,3), (3,2), (3,3))) self.regions = rows + columns + sectors def check(self, sudoku): if not isinstance(sudoku, list) or len(sudoku) != 4: return False for row in sudoku: if not isinstance(sudoku, list) or len(row) != 4: return False for number in row: if not (isinstance(number, int) and 0 <= number <= 4): return False for region in self.regions: numbers = set() for (i, j) in region: n = sudoku[i][j] if n != 0 and n in numbers: return False numbers.add(n) return True



test_sudoku_isNotA4x4List_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_isNotAList_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_withNotIntegers_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_withOutOfRangeNumbers_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_withRepeatedNumbersInColumn_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_withRepeatedNumbersInRow_isRejected (test_SudokuValidator.TestSudokuValidator) ... oktest_sudoku_withRepeatedNumbersInSector_isRejected (test_SudokuValidator.TestSudokuValidator) ... ok

----------------------------------------------------------------------Ran 7 tests in 0.001s

OK


Un poco de “teoría”• Las pruebas deben ser

• Legibles

• Fácilmente ejecutables

• Rápidos

• Sin estado

• Las pruebas guían el diseño y evitan la sobreingeniería: YAGNI (You ain’t gonna need it)

• La refactorización es más segura: los cambios se prueban instantáneamente contra una batería de pruebas de aceptación








Pruebas de aceptación2. Dada una cadena con 4 líneas de caracteres entre 1 y 4 y

asteriscos en posición libre, obtener las lista que lo describe

2.1. Si se pasa un dato que no es una cadena, debe rechazarla

2.2. Si la cadena no tiene 4 líneas de 4 caracteres, debe rechazarla

2.3. Si tiene caracteres diferentes de ‘1’, ‘2’, ‘3’, ‘4’ o ‘*’ en las líneas, debe rechazarla

2.4. Si se le pasa una cadena correcta, debe proporcionar la lista de lista correspondiente


import unittestfrom sudoku.parser import SudokuParser

class TestSudokuParser(unittest.TestCase): def setUp(self): self.parser = SudokuParser() def test_parses_withNonString_returnsParseException(self): unproper_sudoku = 0 self.assertRaises(TypeError, self.parser.parse, unproper_sudoku)

def test_parses_unproperSizeString_returnsParseException(self): unproper_sudoku="""***************""" self.assertRaises(ValueError, self.parser.parse, unproper_sudoku)

def test_parses_invalidChars_returnsParseException(self): unproper_sudoku="""***************=""" self.assertRaises(ValueError, self.parser.parse, unproper_sudoku)

def test_parses_validSudoku_returnsSudoku(self): sudoku="""1****2****3****4""" self.assertEquals(self.parser.parse(sudoku), [[1,0,0,0], [0,2,0,0], [0,0,3,0], [0,0,0,4]])











3.1. Dado un sudoku completo, devolverlo tal cual

3.2. Dado un sudoku incompleto, devolverlo resuelto


import unittestfrom sudoku.solver import SudokuSolver

class TestSudokuSolver(unittest.TestCase):

def setUp(self): self.solver = SudokuSolver() self.sudoku = [[0,0,4,0],[1,0,0,0], [0,0,0,3], [0,1,0,0]] self.solution = [[[2, 3, 4, 1], [1, 4, 3, 2], [4, 2, 1, 3], [3, 1, 2, 4]]] def test_solver_withCompleteSudoku_returnSameSudoku(self): self.assertEquals(list(self.solver.solve(self.solution[0])), self.solution)

def test_solver_withValidSudoku_returnSolution(self): self.assertEquals(list(self.solver.solve(self.sudoku)), self.solution)



from copy import deepcopy

class SudokuSolver: def __init__(self): self.rows = tuple(tuple((i, j) for j in range(4)) for i in range(4)) self.columns = tuple(tuple((i, j) for i in range(4)) for j in range(4)) sectors = (((0,0), (0,1), (1,0), (1,1)), ((0,2), (0,3), (1,2), (1,3)), ((2,0), (2,1), (3,0), (3,1)), ((2,2), (2,3), (3,2), (3,3))) self.sector = {} for sector in sectors: for (i, j) in sector: self.sector[i, j] = sector self.regions = self.rows + self.columns + sectors

def solve(self, sudoku): return self._backtrack(deepcopy(sudoku), 0, 0)

def _backtrack(self, sudoku, i, j): for n in self._options(sudoku, i, j): old_value, sudoku[i][j] = sudoku[i][j], n sudoku[i][j] = n if self._has_next(i, j): for solution in self._backtrack(sudoku, *self._next(i, j)): yield solution else: yield deepcopy(sudoku) sudoku[i][j] = old_value


import unittestfrom sudoku.solver import SudokuSolver

class TestSudokuSolver(unittest.TestCase):

def setUp(self): self.solver = SudokuSolver() self.sudoku = [[0,0,4,0],[1,0,0,0], [0,0,0,3], [0,1,0,0]] self.solution = [[[2, 3, 4, 1], [1, 4, 3, 2], [4, 2, 1, 3], [3, 1, 2, 4]]] def test_solver_withCompleteSudoku_returnSameSudoku(self): self.assertEquals(list(self.solver.solve(self.solution[0])), self.solution)

def test_solver_withValidSudoku_returnSolution(self): self.assertEquals(list(self.solver.solve(self.sudoku)), self.solution)

def test_options_ofFreeCell_areEnumerated(self): options = set(self.solver._options(self.sudoku, 0, 0)) self.assertEquals(options, {2,3})

def test_options_ofCellWithNumber_isTheNumber(self): options = set(self.solver._options(self.sudoku, 0, 2)) self.assertEquals(options, {4})

def test_hasNext_beforeLast_returnTrue(self): self.assertTrue(self.solver._has_next(3, 2))

def test_hasNext_atLast_returnTrue(self): self.assertFalse(self.solver._has_next(3, 3))

def test_next_fromOrigin_iteratesAllCellIndices(self): (x, y) = (0, 0) for i in range(4): for j in range(4): self.assertEquals((x,y), (i,j)) if self.solver._has_next(x, y): (x, y) = self.solver._next(x, y)



class SudokuSolver:

...

def _has_next(self, i, j): if i < 3: return True if j < 3: return True return False

def _next(self, i, j): if j < 3: return (i, j+1) if i < 3: return (i+1, 0) def _options(self, sudoku, i, j): if sudoku[i][j] != 0: yield sudoku[i][j] else: used = set(sudoku[x][y] for (x, y) in self.rows[i] + self.columns[j] \ + self.sector[i, j]) for n in set(range(1, 5)) - used: yield n








Nos faltas historias de usuario

• Ahora caemos en que hemos de preparar una visualización apropiada para el Sudoku

• ¿Cómo?


Historias de usuario1. Dada una lista con 4 filas de números, saber si

describe un Sudoku de 4x4



4. Presentar gráficamente los Sudoku



import unittestfrom sudoku.presenter import SudokuPresenter

class TestSudokuPresenter(unittest.TestCase):

def setUp(self): self.presenter = SudokuPresenter()

def test_show_validSudoku_returnValidString(self): sudoku = [[0, 0, 3, 0], [4, 0, 1, 0], [0, 1, 4, 3], [0, 0, 0, 0]] presentation = """ 1 2 3 4 +-+-+-+-+1 | | |3| | +-+-+-+-+2 |4| |1| | +-+-+-+-+3 | |1|4|3| +-+-+-+-+4 | | | | | +-+-+-+-+""" self.assertEquals(self.presenter.show(sudoku), presentation)



class SudokuPresenter: def show(self, sudoku): s = [] s.append(" 1 2 3 4") for (i, row) in enumerate(sudoku): s.append(" +-+-+-+-+") s.append("{} |".format(i+1)) for number in row: r = " " if number == 0 else repr(number) s[-1] += r + "|" s.append(" +-+-+-+-+") return '\n'.join(s)


Historias de usuario1. Dada una lista con 4 filas de números, saber si

describe un Sudoku de 4x4



4. Presentar gráficamente los Sudoku



¿Cómo hacemos pruebas con un humano?

• Se usan impostores (dobles de prueba) para simular el acceso a recursos:

• de producción y/o que interactúan con el entorno

• demasiado lentos para las pruebas

• tan complejos que podrían fallar y llamarnos a engaño sobre el responsable del fallo


Herramientas

• Mockito for Python

• Mockito es un framework para Java, con port para Python 3.1

• http://code.google.com/p/mockito/

• http://code.google.com/p/mockito/wiki/MockitoForPython


http://code.google.com/p/mockito/

http://code.google.com/p/mockito/

http://code.google.com/p/mockito/wiki/MockitoForPython

http://code.google.com/p/mockito/wiki/MockitoForPython

Un jugador “impostable”

• Vamos a diseñar una clase que modela al jugador

• El jugador introducirá coordenadas de la casilla que quiere modificar y el número que quiere poner en esa casilla (0 será borrar)


class SudokuPlayer(): def get_coordinates_and_number(self): while True: print("Play i j n:", end="") line = input().strip() words = line.split() if len(words) == 3: try: i = int(words[0]) j = int(words[1]) n = int(words[2]) if 1 <= i <= 4 and 1 <= j <= 4 and 0 <= n <= 9: return (i-1, j-1, n) else: raise ValueError() except ValueError: print("Invalid input")

Feo: imprime en pantalla, lee de teclado.Difícil de impostar: no hay costuras (seams)


class SudokuPlayer(): def __init__(self, prompt=lambda: print("Play i j n:", end=""), notify_error = lambda: print("Invalid input"), get_input=input): self.prompt = prompt self.notify_error = notify_error self.get_input = get_input def get_coordinates_and_number(self): while True: self.prompt() line = self.get_input().strip() words = line.split() if len(words) == 3: try: i = int(words[0]) j = int(words[1]) n = int(words[2]) if 1 <= i <= 4 and 1 <= j <= 4 and 0 <= n <= 9: return (i-1, j-1, n) else: raise ValueError() except ValueError: self.notify_error()

Podemos impostar la propia I/Oviernes 9 de abril de 2010

import unittestfrom sudoku.player import SudokuPlayerfrom io import StringIOfrom mockito import *

class TestSudokuPlayer(unittest.TestCase):

def test_getCoordinatesAndNumber_readsGoodUserValues_returnsProperValues(self): ioMock = Mock() #@UndefinedVariable when(ioMock).get_input().thenReturn("1 1 1") #@UndefinedVariable output = StringIO() player = SudokuPlayer(prompt=lambda: None, notify_error=lambda: None, get_input=ioMock.get_input) (i, j, n) = player.get_coordinates_and_number() verify(ioMock, times=1).get_input() #@UndefinedVariable self.assertEquals((i,j,n), (0,0,1)) output.close()

def test_getCoordinatesAndNumber_readsBadAndGoodUserValues_returnsProperValues(self): ioMock = Mock() #@UndefinedVariable when(ioMock).get_input().thenReturn("1 1 100").thenReturn("1 1 1") #@UndefinedVariable output = StringIO() player = SudokuPlayer(prompt=lambda: None, notify_error=lambda: None, get_input=ioMock.get_input) (i, j, n) = player.get_coordinates_and_number() verify(ioMock, times=2).get_input() #@UndefinedVariable self.assertEquals((i,j,n), (0, 0, 1)) output.close()

def test_getCoordinatesAndNumber_readsBadAndGoodUserValues_errorIsNotified(self): ioMock = Mock() #@UndefinedVariable when(ioMock).notify_error().thenReturn("ERROR") #@UndefinedVariable when(ioMock).get_input().thenReturn("1 1 100").thenReturn("1 1 1") #@UndefinedVariable output = StringIO() player = SudokuPlayer(prompt=lambda: None, notify_error=ioMock.notify_error, get_input=ioMock.get_input) (i, j, n) = player.get_coordinates_and_number() verify(ioMock, times=1).notify_error() #@UndefinedVariable output.close() if __name__ == "__main__": #import sys;sys.argv = ['', 'Test.testName'] unittest.main()


class TestSudokuPlayer(unittest.TestCase):

def test_getCoordinatesAndNumber_readsGoodUserValues_returnsProperValues(self): ioMock = Mock() #@UndefinedVariable when(ioMock).get_input().thenReturn("1 1 1") #@UndefinedVariable output = StringIO() player = SudokuPlayer(prompt=lambda: None, notify_error=lambda: None, get_input=ioMock.get_input) (i, j, n) = player.get_coordinates_and_number() verify(ioMock, times=1).get_input() #@UndefinedVariable self.assertEquals((i,j,n), (0,0,1)) output.close()

verificación

Fake/Stub

Mock

Fake/Stub


Mocks aren’t Stubs (Martin Fowler)

• Dummy objects are passed around but never actually used. Usually they are just used to fill parameter lists.

• Fake objects actually have working implementations, but usually take some shortcut which makes them not suitable for production (an in memory database is a good example).

• Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what's programmed in for the test. Stubs may also record information about calls, such as an email gateway stub that remembers the messages it 'sent', or maybe only how many messages it 'sent'.

• Mocks are what we are talking about here: objects pre-programmed with expectations which form a specification of the calls they are expected to receive.


http://www.martinfowler.com/bliki/InMemoryTestDatabase.html

http://www.martinfowler.com/bliki/InMemoryTestDatabase.html

import unittestfrom sudoku.game import SudokuGamefrom sudoku.player import SudokuPlayerfrom mockito import *

class TestSudokuGame(unittest.TestCase):

def test_game_withInvalidSudokuString_raisesException(self): game = SudokuGame(sudoku_chooser=lambda x: "") self.assertRaises(ValueError, game.start, None)

def test_game_withIncompleteSudoku_raisesException(self): game = SudokuGame(sudoku_chooser=lambda x: "234\n341*\n214*\n*321") self.assertRaises(ValueError, game.start, None)

def test_game_withImpossibleSudoku_raisesException(self): game = SudokuGame(sudoku_chooser=lambda x: "2234\n341*\n214*\n*321") self.assertRaises(ValueError, game.start, None)

def test_game_withValidSudoku_plasyOK(self): player = Mock() #@UndefinedVariable when(player).get_coordinates_and_number().thenReturn((0,0,1)) \ .thenReturn((1,3,2)) \ .thenReturn((2,3,3)) \ .thenReturn((3,0,4))

game = SudokuGame(sudoku_chooser=lambda x: "*234\n341*\n214*\n*321") self.assertTrue(game.start(player))



from sudoku.solver import SudokuSolverfrom sudoku.presenter import SudokuPresenterfrom sudoku.validator import SudokuValidatorfrom sudoku.parser import SudokuParserfrom sudoku.player import SudokuPlayer

from random import choicefrom copy import deepcopy

class SudokuGame: def __init__(self, sudoku_chooser=lambda sudokus: choice(sudokus)): self.parser = SudokuParser() self.validator = SudokuValidator() self.solver = SudokuSolver() self.presenter = SudokuPresenter() self.sudoku_chooser = sudoku_chooser self.sudokus = ["2143\n4**1\n1**4\n3412", "*234\n341*\n214*\n*321", "*23*\n1**4\n2**3\n*14*", "4**2\n*31*\n*42*\n3**1", "4*1*\n1*2*\n*4*1\n*1*2", "12**\n**21\n24**\n**42", "*13*\n****\n****\n3421", "*3*1\n**2*\n**3*\n*4*2", "****\n12**\n3***\n***1", "**3*\n****\n*2**\n*14*"] def start(self, player): sudoku_string = self.sudoku_chooser(self.sudokus) sudoku = self.parser.parse(sudoku_string) if not self.validator.check(sudoku): raise ValueError("Invalid Sudoku\n" + self.presenter.show(sudoku)) original_sudoku = deepcopy(sudoku) print(self.presenter.show(sudoku)) while not self.validator.complete(sudoku): (i, j, n) = player.get_coordinates_and_number() if sudoku[i][j] == 0: sudoku[i][j] = n if not self.validator.check(sudoku): sudoku[i][j] = 0 elif n == 0 and original_sudoku[i][j] == 0: sudoku[i][j] = 0 print(self.presenter.show(sudoku)) return True if __name__ == "__main__": game = SudokuGame() game.start(SudokuPlayer())


from sudoku.solver import SudokuSolverfrom sudoku.presenter import SudokuPresenterfrom sudoku.validator import SudokuValidatorfrom sudoku.parser import SudokuParserfrom sudoku.player import SudokuPlayer

from random import choicefrom copy import deepcopy

class SudokuGame: def __init__(self, sudoku_chooser=lambda sudokus: choice(sudokus)): self.parser = SudokuParser() self.validator = SudokuValidator() self.solver = SudokuSolver() self.presenter = SudokuPresenter() self.sudoku_chooser = sudoku_chooser self.sudokus = ["2143\n4**1\n1**4\n3412", "*234\n341*\n214*\n*321", "*23*\n1**4\n2**3\n*14*", "4**2\n*31*\n*42*\n3**1", "4*1*\n1*2*\n*4*1\n*1*2", "12**\n**21\n24**\n**42", "*13*\n****\n****\n3421", "*3*1\n**2*\n**3*\n*4*2", "****\n12**\n3***\n***1", "**3*\n****\n*2**\n*14*"] def start(self, player): sudoku_string = self.sudoku_chooser(self.sudokus) sudoku = self.parser.parse(sudoku_string) if not self.validator.check(sudoku): raise ValueError("Invalid Sudoku\n" + self.presenter.show(sudoku)) original_sudoku = deepcopy(sudoku) print(self.presenter.show(sudoku)) while not self.validator.complete(sudoku): (i, j, n) = player.get_coordinates_and_number() if sudoku[i][j] == 0: sudoku[i][j] = n if not self.validator.check(sudoku): sudoku[i][j] = 0 elif n == 0 and original_sudoku[i][j] == 0: sudoku[i][j] = 0 print(self.presenter.show(sudoku)) return True if __name__ == "__main__": game = SudokuGame() game.start(SudokuPlayer())


Pruebas de cobertura

• ¿Hemos puesto a prueba todas y cada una de las líneas de nuestro código?

• Muy importante en lenguajes dinámicos


Herramientas

• coverage.py

• Versión 3.3.1

• Instalación: easy_install coverage

• http://nedbatchelder.com/code/coverage/


http://nedbatchelder.com/code/coverage/

http://nedbatchelder.com/code/coverage/

import osimport unittestimport coverageimport importlibfrom unittest import TestResult

def find_test_paths(startDir="test"): result = [] directories = [startDir] while len(directories)>0: directory = directories.pop() for name in os.listdir(directory): fullpath = os.path.join(directory,name) if os.path.isfile(fullpath) and \ name.startswith("test"): result.append(fullpath) elif os.path.isdir(fullpath): directories.append(fullpath) return result

test_paths = find_test_paths()

cov = coverage.coverage()cov.start()

loaded = set()suite = unittest.TestSuite()for module in test_paths: mod = importlib.import_module(''.join(

module.split(".")[:-1]).replace("/", ".")) exec("import {}".format(mod.__name__)) for c in dir(mod): if c.startswith("Test"): fullname = mod.__name__ + "." + c testclass = eval(fullname) if testclass not in loaded: loaded.add(testclass) suite.addTest(unittest.TestLoader()\ .loadTestsFromTestCase(testclass))

result = TestResult()suite.run(result)print(result)cov.stop()cov.report()


<unittest.TestResult run=52 errors=0 failures=0>Name Stmts Exec Cover Missing---------------------------------------------------------sudoku/__init__ 1 1 100% sudoku/game 35 30 85% 40-42, 47-48sudoku/parser 16 16 100% sudoku/player 20 20 100% sudoku/presenter 12 12 100% sudoku/solver 36 36 100% sudoku/validator 36 34 94% 17, 44test/__init__ 1 1 100% test/test_SudokuGame 21 20 95% 33test/test_SudokuParser 19 18 94% 38test/test_SudokuPlayer 34 33 97% 49test/test_SudokuPresenter 11 10 90% 27test/test_SudokuSolver 30 29 96% 41test/test_SudokuValidator 28 27 96% 39---------------------------------------------------------TOTAL 300 287 95%


algoritmiaUna librería de estructuras de datos, algoritmos clásicos

y esquemas algorítmicos

MIT License


Mercurial

• Versión 1.5

• http://mercurial.selenic.com


http://mercurial.selenic.com

http://mercurial.selenic.com

HgEclipse

• Versión 1.5

• http://www.javaforge.com/project/HGE

• Instalación: http://hge.javaforge.com/hgeclipse


http://hge.javaforge.com/mercurialeclipse-snapshots





CodePlex

• Repositorio Mercurial con el proyecto algoritmia

• http://algoritmica.codeplex.com


http://algoritmica.codeplex.com

http://algoritmica.codeplex.com

Clonar algoritmia



Importar algoritmia



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