How robot framework is used in Automation testing in Embedded Systems?

Introduction#

Robot framework is widely used in Automation testing of Embedded products. We are going to take an Embedded product as an example and see how to automate the test cases using Robot Framework.

Remarks#

Abbreviation:

RPS - Remote power supply
RF - Robot frame work

Remote Power Supply Testing

Remote Power supply simulation

Since we don’t have a real remote power supply hardware, we are going to simulate it using python program.

Basic idea about RPS

Actually remote power supply has a http server.
User can send commands to turn ON/OFF power supply using http request.

We are going to simulate remote power supply using following program rps-server.py.

from flask import Flask, request
from flask_httpauth import HTTPBasicAuth


app = Flask(__name__)
auth = HTTPBasicAuth()

users = {
        'admin': '12345678'
}
app.url_map.strict_slashes = False

PINS = ['P60', 'P61', 'P62', 'P63']

PINS_STATUS = {'P60':'0', 'P61': '0', 'P62':'0', 'P63':'0'}

@auth.get_password
def get_pw(username):
        if username in users:
                return users.get(username)
        return None

@app.route('/')
@auth.login_required
def index():
        return "Hello, %s!" % auth.username()

def get_html_string():
        html_str = '<html>P60={}P61={}P62={}P63={}</html>'.format(PINS_STATUS['P60'],
                                                PINS_STATUS['P61'],
                                            PINS_STATUS['P62'],
                                            PINS_STATUS['P63'])
        return html_str

def parse_cmd_args(args):
        global current_status
        if str(args['CMD']) == 'SetPower':
                for key in args:
                        if key in PINS:
                                PINS_STATUS[key] = str(args[key])
                            
                return get_html_string()
    
        if str(args['CMD']) == 'GetPower':
                return get_html_string()
   

    @app.route('/SetCmd', methods=['GET','POST'])
    def rps():
        if request.method=="GET":
                args=request.args.to_dict()
                ret = parse_cmd_args(args)
                return ret

The above code actually simulates http server to control the remote power supply.

How to Run RPS server ?

$ export FLASK_APP=rps-server.py
$ flask run

How to send commands to rps server ?

Following are the two commands used to control the RPS

SetPower
GetPower

By default the server will be listening at the port 5000.

The power supply ports are,

The states of the ports are,

ON - 1
OFF - 0

Requirements

Requirements for building a remote power supply are

Remote power supply should be able to turn ON/OFF remotely
Remote power supply status can be accessed remotely.

Deriving test cases

Test cases derived from requirement

Turn on Power supply 2 remotely.
Verify power supply 2 is on.
Turn off Power supply 2 remotely.
Verify power supply 2 is off.

Manual Testing

Run the rps server.
To turn on Port 3, open a browser and give following URI

https://admin:12345678@localhost:5000/SetCmd?CMD=SetPower&P62=1

To get the status of all the ports

https://admin:12345678@localhost:5000/SetCmd?CMD=GetPower

Writing test library

We need to write a test library in python for sending http commands using http request. Later we will be using this library as keywords in robot frame work.

commands.py

We are going to use library from commands.py to send SetPower and GetPower.

import requests
import re


class commands(object):

    ROBOT_LIBRARY_SCOPE = 'GLOBAL'
    def __init__(self, ip='localhost:5000'):
        self.ip_address = ip
        self.query = {}
        self.user = 'admin'
        self.passw = '12345678'

    def form_query(self, state, cmd, port):
        port = self.get_port_no(port)
        self.query = {port: state}
        return self.query

    def get_port_no(self, port_no):
        port = 'P6' + str(port_no)
        return port

    def clean_html(self, data):
        exp = re.compile('<.*?>')
        text = re.sub(exp, "", data)
        return text.rstrip()

    def send_cmds(self, cmd, port=None, state=None):
        url = 'https://{}:{}@{}/SetCmd?CMD={}'\
              .format(self.user,
                      self.passw,
                      self.ip_address,
                      cmd)
        print url
        if cmd == 'SetPower':
            self.form_query(state, cmd, port)
            self.req = requests.get(url, params=self.query)
            return True
        elif cmd == 'GetPower':
            self.req = requests.get(url)
            data = self.clean_html(self.req.text)
            return data
        else:
            return False

        return self.req.text


# c = commands('localhost:5000')

# c.send_cmds('SetPower', 2, 1)
# c.send_cmds('SetPower', 3, 1)
# print c.send_cmds('GetPower')

Python key word documentation

send_cmds(cmd, port=None, state=None) is the function we are going to use.
While using this function in Robot key word, no need to bother about _, or Lowercaser or Uppercase in function name.

Python function will look like this while using as keyword,

Send Cmds       cmd   port  state

Writing test Keywords

We are going to use Send Cmds as python keyword in test suite.

RPS send commands uses following four arguments to set power
- command = SetPower
- port = 2
- state = 1 for ON / 0 for off
When we call that command it will turn ON/OFF the power supply
RPS get power will return the status of all the Power supply ports

*** Keywords *** RPS send commands [Arguments] ${command} ${port} ${state} ${output}= Send cmds ${command} ${port} ${state} [return] ${output}

RPS get Power [Arguments] ${command} ${output}= Send cmds ${command} [return] ${output}}

Algorithm to test power supply

Set power to a port
Check the status of cmd
Get the status of the port and check whether it is ON/OFF

Writing test cases using the above key words

Now we are ready to write test case using following two keywords

RPS send commands - To set and unset a power of port
RPS get power - To get the status of all the port

*** Settings *** Library commands.py

*** Test Cases *** Turn on Power supply 2 remotely ${out}= RPS send commands SetPower 2 1 Should be equal ${out} ${True}

Verify power supply 2 is on ${out}= RPS get power GetPower should contain ${out} P62=1

Turn off Power supply 2 remotely ${out}= RPS send commands SetPower 2 0 Should be equal ${out} ${True}

Verify power supply 2 is off ${out}= RPS get power GetPower should contain ${out} P62=0

Create a file name remote-power-supply.robot

Copy above key words and test case in to the file.

How to execute RPS server and remote-power-supply.robot ?

Run remote power supply first
Run the test suite remote-power-supply.robot

$ export FLASK_APP=rps-server.py $ flask run $ pybot remote-power-supply.robot

Output

$ pybot remote-pwer-supply.robot 
==============================================================================
Remote-Pwer-Supply                                                            
==============================================================================
Turn on Power supply 2 remotely                                       | PASS |
------------------------------------------------------------------------------
Verify power supply 2 is on                                           | PASS |
------------------------------------------------------------------------------
Turn off Power supply 2 remotely                                      | PASS |
------------------------------------------------------------------------------
Verify power supply 2 is off                                          | PASS |
------------------------------------------------------------------------------    
Remote-Pwer-Supply                                                    | PASS |
4 critical tests, 4 passed, 0 failed
4 tests total, 4 passed, 0 failed
==============================================================================
Output:  /tmp/talks/robot-framework-intro/test-cases/output.xml
Log:     /tmp/talks/robot-framework-intro/test-cases/log.html
Report:  /tmp/talks/robot-framework-intro/test-cases/report.html

Following two diagrams explains about test architecture between RPS and RF

Remote Power supply test architecture

Robot frame work architecture

Credits

Thanks to robot framework for architecture diagram.

The complete code is available here

Remote power supply

commands.py

remote-power-supply.robot