Facade.py

#!/usr/bin/python
# -*- coding : utf-8 -*-


"""
The Facade design pattern is one of the twenty-three well-known GoF design patterns that describe
how to solve recurring design problems to design flexible and reusable object-oriented software,
that is, objects that are easier to implement, change, test, and reuse.

*What problems can the Facade design pattern solve?

- To make a complex subsystem easier to use, a simple interface should be provided for a set of
  interfaces in the subsystem.
- The dependencies on a subsystem should be minimized.

Clients that access a complex subsystem directly refer to (depend on) many different objects having
different interfaces (tight coupling), which makes the clients hard to implement, change, test, and reuse.

*What solution does the Facade design pattern describe?

Define a Facade object that

- implements a simple interface in terms of (by delegating to) the interfaces in the subsystem and
- may perform additional functionality before/after forwarding a request.

Reference: https://en.wikipedia.org/wiki/Facade_pattern
"""


from __future__ import print_function
import time

SLEEP = 0.1


# Complex Parts
class TC1:
    def run(self):
        print(u"###### In Test 1 ######")
        time.sleep(SLEEP)
        print(u"Setting up")
        time.sleep(SLEEP)
        print(u"Running test")
        time.sleep(SLEEP)
        print(u"Tearing down")
        time.sleep(SLEEP)
        print(u"Test Finished\n")


class TC2:
    def run(self):
        print(u"###### In Test 2 ######")
        time.sleep(SLEEP)
        print(u"Setting up")
        time.sleep(SLEEP)
        print(u"Running test")
        time.sleep(SLEEP)
        print(u"Tearing down")
        time.sleep(SLEEP)
        print(u"Test Finished\n")


class TC3:
    def run(self):
        print(u"###### In Test 3 ######")
        time.sleep(SLEEP)
        print(u"Setting up")
        time.sleep(SLEEP)
        print(u"Running test")
        time.sleep(SLEEP)
        print(u"Tearing down")
        time.sleep(SLEEP)
        print(u"Test Finished\n")


# Facade
class TestRunner:
    def __init__(self):
        self.tc1 = TC1()
        self.tc2 = TC2()
        self.tc3 = TC3()
        self.tests = [self.tc1, self.tc2, self.tc3]

    def runAll(self):
        [i.run() for i in self.tests]


# Client
if __name__ == '__main__':
    testrunner = TestRunner()
    testrunner.runAll()

# ---- OUTPUT: ---- :
#
# ###### In Test 1 ######
# Setting up
# Running test
# Tearing down
# Test Finished
#
# ###### In Test 2 ######
# Setting up
# Running test
# Tearing down
# Test Finished
#
# ###### In Test 3 ######
# Setting up
# Running test
# Tearing down
# Test Finished