php-tdd-example

This example contains a product retriever class to retriever a product from a data storage. In the example elasticsearch is used as the as the data storage.

There are a couple of simple test-cases that covers:

• If a product is not found (Elasticsearch returns 404).
• The storage engine is not available.
• The given id of the product is not a valid id.
• Happy path example.

There's no real data in elasticsearch. The client and data is mocked to create the tests.

The product entity contains of the following fields:

• productId (int)
• name (string)
• salesPrice (float)

Installation

The install and run the test of the code we need a couple of tools:

• Php5
• Php5-curl
• Composer
• Phpunit
• git

Installation on Linux

Use the package manager of your OS: yum or apt-get for example. In this example apt-get is used. Install php5 and php5-curl.

sudo apt-get update
sudo apt-get install php5
sudo apt-get install php5
sudo apt-get install php5-curl

Install the php package manager composer. For easy use install it globally.

sudo curl -sS https://getcomposer.org/installer | sudo php -- --install-dir=/usr/local/bin
sudo ln -s /usr/local/bin/composer.phar /usr/local/bin/composer

Install the phpunit globally so you can use it from the command line.

sudo composer global require "phpunit/phpunit=4.1.*"
sudo composer global require "phpunit/php-invoker=~1.1."

To retrieve the code we need git.

sudo apt-get install git

Now you can clone the git repository, checkout the code and install the packages.

git clone https://github.com/rregeer/php-tdd-example
cd php-tdd-example
sudo composer install

The tests can be run using phpunit on the command line

cd php-tdd-example
phpunit test/

Exercise 1: finding bugs.

All the tests are running, but is everything ok?. There can be still bugs in the code we haven't seen and covered. Take a look at the tests and the code and see if everything is covered and the code is correct. If you found the bug(s). Correct the code and create a test for it so the bug will never happen again. Hint take a good look at the product entity in the documentation and of implementation.

Exercise 2: extending result and refactor code.

Add salesprice and product information to the product. If there´s no salesprice then the salesprice is null. If there´s no product information then the product information is null. All the data is in the "product" index the type is "product".

Product:

• productId (int)
• productInformation (object)
• salesPrice (object)

ProductInformation:

• shortName (string)
• fullName (string)
• description (string)

SalesPrice:

• priceExcludingVat (float)
• priceIncludingVat (float)

Example of the elastic-search response:

_source: {
  id: 123456,
  productInformation: {
    shortName: "Apple iPhone 6 GB",
    fullName: "Apple Iphone 6 special edition",
    description: "The Apple Iphone 6 special edition."
    },
    salesPrice: {
      priceExcludingVat: 660.33058,
      priceIncludingVat: 799
    }
  }
}

Exercise 3: refactor code and add new functionality.

Add brand information to the product. If there´s no brand information then the brand is null. The brand is in a separate elastic-search index "brand". The type is "brand". The brand can also be retrieved separately from the product.

Brand:

• brandId (int)
• name (string)

Product:

• brand (object)
• productId (int)
• productInformation (object)
• salesPrice (object)

Example of the product elastic-search response:

_source: {
  id: 123456,
  brandId: 32,
  productInformation: {
    shortName: "Apple iPhone 6 GB",
    fullName: "Apple Iphone 6 special edition",
    description: "The Apple Iphone 6 special edition."
    },
    salesPrice: {
      priceExcludingVat: 660.33058,
      priceIncludingVat: 799
    }
  }
}

Example of the brand elastic-search response:

_source: {
  id: 12,
  name: "Apple"
}