#Vending Machine Kata In this exercise you will build the brains of a vending machine. It will accept money, make change, maintain inventory, and dispense products. All the things that you might expect a vending machine to accomplish.
The point of this kata to to provide an larger than trivial exercise that can be used to practice TDD. A significant portion of the effort will be in determining what tests should be written and, more importantly, written next.
##Features Accept Coins
##As a vendor I want a vending machine that accepts coins So that I can collect money from the customer
The vending machine will accept valid coins (nickels, dimes, and quarters) and reject invalid ones (pennies). When a valid coin is inserted the amount of the coin will be added to the current amount and the display will be updated. When there are no coins inserted, the machine displays INSERT COIN. Rejected coins are placed in the coin return.
NOTE: The temptation here will be to create Coin objects that know their value. However, this is not how a real vending machine works. Instead, it identifies coins by their weight and size and then assigned a value to what was inserted. You will need to do something similar. This can be simulated using strings, constants, enums, symbols, or something of that nature.
#Select Product
##As a vendor I want customers to select products So that I can give them an incentive to put money in the machine
There are three products: cola for $1.00, chips for $0.50, and candy for $0.65. When the respective button is pressed and enough money has been inserted, the product is dispensed and the machine displays THANK YOU. If the display is checked again, it will display INSERT COINS and the current amount will be set to $0.00. If there is not enough money inserted then the machine displays PRICE and the price of the item and subsequent checks of the display will display either INSERT COINS or the current amount as appropriate.
#Make Change
##As a vendor I want customers to receive correct change So that they will use the vending machine again
When a product is selected that costs less than the amount of money in the machine, then the remaining amount is placed in the coin return.
##Return Coins
##As a customer I want to have my money returned So that I can change my mind about buying stuff from the vending machine
When the return coins is selected, the money the customer has placed in the machine is returned and the display shows INSERT COIN.
##Sold Out
##As a customer I want to be told when the item I have selected is not available So that I can select another item
When the item selected by the customer is out of stock, the machine displays SOLD OUT. If the display is checked again, it will display the amount of money remaining in the machine or INSERT COIN if there is no money in the machine.
##Exact Change Only
As a customer I want to be told when exact change is required So that I can determine if I can buy something with the money I have before inserting it
When the machine is not able to make change with the money in the machine for any of the items that it sells, it will display EXACT CHANGE ONLY instead of INSERT COINS.
This project is an application skeleton for a typical AngularJS web app. You can use it to quickly bootstrap your angular webapp projects and dev environment for these projects.
The seed contains a sample AngularJS application and is preconfigured to install the Angular framework and a bunch of development and testing tools for instant web development gratification.
The seed app doesn't do much, just shows how to wire two controllers and views together.
To get you started you can simply clone the angular-seed repository and install the dependencies:
You need git to clone the angular-seed repository. You can get git from http://git-scm.com/.
We also use a number of node.js tools to initialize and test angular-seed. You must have node.js and its package manager (npm) installed. You can get them from http://nodejs.org/.
Clone the angular-seed repository using git:
git clone https://github.com/angular/angular-seed.git
cd angular-seed
If you just want to start a new project without the angular-seed commit history then you can do:
git clone --depth=1 https://github.com/angular/angular-seed.git <your-project-name>
The depth=1
tells git to only pull down one commit worth of historical data.
We have two kinds of dependencies in this project: tools and angular framework code. The tools help us manage and test the application.
- We get the tools we depend upon via
npm
, the node package manager. - We get the angular code via
bower
, a client-side code package manager.
We have preconfigured npm
to automatically run bower
so we can simply do:
npm install
Behind the scenes this will also call bower install
. You should find that you have two new
folders in your project.
node_modules
- contains the npm packages for the tools we needapp/bower_components
- contains the angular framework files
Note that the bower_components
folder would normally be installed in the root folder but
angular-seed changes this location through the .bowerrc
file. Putting it in the app folder makes
it easier to serve the files by a webserver.
We have preconfigured the project with a simple development web server. The simplest way to start this server is:
npm start
Now browse to the app at http://localhost:8000/app/index.html
.
app/ --> all of the source files for the application
app.css --> default stylesheet
components/ --> all app specific modules
version/ --> version related components
version.js --> version module declaration and basic "version" value service
version_test.js --> "version" value service tests
version-directive.js --> custom directive that returns the current app version
version-directive_test.js --> version directive tests
interpolate-filter.js --> custom interpolation filter
interpolate-filter_test.js --> interpolate filter tests
view1/ --> the view1 view template and logic
view1.html --> the partial template
view1.js --> the controller logic
view1_test.js --> tests of the controller
view2/ --> the view2 view template and logic
view2.html --> the partial template
view2.js --> the controller logic
view2_test.js --> tests of the controller
app.js --> main application module
index.html --> app layout file (the main html template file of the app)
index-async.html --> just like index.html, but loads js files asynchronously
karma.conf.js --> config file for running unit tests with Karma
e2e-tests/ --> end-to-end tests
protractor-conf.js --> Protractor config file
scenarios.js --> end-to-end scenarios to be run by Protractor
There are two kinds of tests in the angular-seed application: Unit tests and End to End tests.
The angular-seed app comes preconfigured with unit tests. These are written in Jasmine, which we run with the Karma Test Runner. We provide a Karma configuration file to run them.
- the configuration is found at
karma.conf.js
- the unit tests are found next to the code they are testing and are named as
..._test.js
.
The easiest way to run the unit tests is to use the supplied npm script:
npm test
This script will start the Karma test runner to execute the unit tests. Moreover, Karma will sit and watch the source and test files for changes and then re-run the tests whenever any of them change. This is the recommended strategy; if your unit tests are being run every time you save a file then you receive instant feedback on any changes that break the expected code functionality.
You can also ask Karma to do a single run of the tests and then exit. This is useful if you want to check that a particular version of the code is operating as expected. The project contains a predefined script to do this:
npm run test-single-run
The angular-seed app comes with end-to-end tests, again written in Jasmine. These tests are run with the Protractor End-to-End test runner. It uses native events and has special features for Angular applications.
- the configuration is found at
e2e-tests/protractor-conf.js
- the end-to-end tests are found in
e2e-tests/scenarios.js
Protractor simulates interaction with our web app and verifies that the application responds correctly. Therefore, our web server needs to be serving up the application, so that Protractor can interact with it.
npm start
In addition, since Protractor is built upon WebDriver we need to install this. The angular-seed project comes with a predefined script to do this:
npm run update-webdriver
This will download and install the latest version of the stand-alone WebDriver tool.
Once you have ensured that the development web server hosting our application is up and running and WebDriver is updated, you can run the end-to-end tests using the supplied npm script:
npm run protractor
This script will execute the end-to-end tests against the application being hosted on the development server.
Previously we recommended that you merge in changes to angular-seed into your own fork of the project. Now that the angular framework library code and tools are acquired through package managers (npm and bower) you can use these tools instead to update the dependencies.
You can update the tool dependencies by running:
npm update
This will find the latest versions that match the version ranges specified in the package.json
file.
You can update the Angular dependencies by running:
bower update
This will find the latest versions that match the version ranges specified in the bower.json
file.
The angular-seed project supports loading the framework and application scripts asynchronously. The
special index-async.html
is designed to support this style of loading. For it to work you must
inject a piece of Angular JavaScript into the HTML page. The project has a predefined script to help
do this.
npm run update-index-async
This will copy the contents of the angular-loader.js
library file into the index-async.html
page.
You can run this every time you update the version of Angular that you are using.
While angular is client-side-only technology and it's possible to create angular webapps that
don't require a backend server at all, we recommend serving the project files using a local
webserver during development to avoid issues with security restrictions (sandbox) in browsers. The
sandbox implementation varies between browsers, but quite often prevents things like cookies, xhr,
etc to function properly when an html page is opened via file://
scheme instead of http://
.
The angular-seed project comes preconfigured with a local development webserver. It is a node.js
tool called http-server. You can start this webserver with npm start
but you may choose to
install the tool globally:
sudo npm install -g http-server
Then you can start your own development web server to serve static files from a folder by running:
http-server -a localhost -p 8000
Alternatively, you can choose to configure your own webserver, such as apache or nginx. Just
configure your server to serve the files under the app/
directory.
This really depends on how complex your app is and the overall infrastructure of your system, but
the general rule is that all you need in production are all the files under the app/
directory.
Everything else should be omitted.
Angular apps are really just a bunch of static html, css and js files that just need to be hosted somewhere they can be accessed by browsers.
If your Angular app is talking to the backend server via xhr or other means, you need to figure out what is the best way to host the static files to comply with the same origin policy if applicable. Usually this is done by hosting the files by the backend server or through reverse-proxying the backend server(s) and webserver(s).
Travis CI is a continuous integration service, which can monitor GitHub for new commits
to your repository and execute scripts such as building the app or running tests. The angular-seed
project contains a Travis configuration file, .travis.yml
, which will cause Travis to run your
tests when you push to GitHub.
You will need to enable the integration between Travis and GitHub. See the Travis website for more instruction on how to do this.
CloudBees have provided a CI/deployment setup:
If you run this, you will get a cloned version of this repo to start working on in a private git repo, along with a CI service (in Jenkins) hosted that will run unit and end to end tests in both Firefox and Chrome.
For more information on AngularJS please check out http://angularjs.org/