write code

write test

tests fail

tests pass

// arrange
var x = 10;
var y = 10;

var expected = 20;

// act
var actual = Math.Add(x, y);

// assert
Assert.AreEqual(expected, actual);

AreEqual failed, expected <10> got <0>

class Math {
    function Add(number x, number y) {
        // TODO: add numbers
        return 0;
    }
}

class Math {
    function Add(number x, number y) {
        return x + y;
    }
}

Test: add numbers
Result: pass

report results

write test

run tests

Given a product costs 100
And VAT is 20%
When a VAT receipt is produced
Then the subtotal is 100
And the total is 120

Feature: Receipts
Scenario: An order with VAT
Running...

Result: failed
> Then the subtotal is 100
Expected 100 got 120

approve changes

define rules

produce acceptance criteria

As a business customer
I want VAT receipts
So that I can do my accounts

Feature: Tax Receipts

Scenario: Order as a UK business
Given a UK business makes an order
When the payment is processed
Then the receipt includes tax information

Scenario: Order as a Lilliput business
Given a Lilliput business makes an order
When the payment is processed
Then the receipt has no tax information

what is specflow:

specflow is a tool kit that brings gherkin testing to .net and Visual Studio

1. tools to help testers write gherkin in VS

it includes:

2. libraries to run gherkin tests

what is gherkin:

gherkin is a business friendly language for tests

gherkin tests live in feature files, e.g. VatReceipt.feature

why:

we get an executable and business friendly language

we can write tests before development is ready

when tests fail the errors are easier to identify

the feature file

Feature:

Feature: ReceiptToClient
	In order to post a receipt from the client into the client account
	I want to be able to post a RTC journal

Scenario:

Scenario: I edit and post a previously saved RTC journal
	Given I have opened a previously saved RTC journal
	When I make changes to the journal and save
	Then I see a message indicating the journal posted 
	And the journal reflects the new changes

Feature describes the feature under test. The code here is not executed.

Scenario defines a test. Each scenario is executed once in a test run.

Given, When and Then must be used to start each test step. You can also use And and But if you are writing more complex tests.

specflow in Visual Studio will generate C# code behind the feature files testers create.

the feature file

Background:

Background: 
	Given I have logged into LexisOne as Eric

Using parameters:

Scenario: I can create a client with the minimum information
	Given I am creating a client with name "Fred" 
        And customer group "UK-CL-UK"
	When I save a new client
	Then the client is saved with no errors

Background is executed before a scenario runs. Use it if you are writing the same Given steps over and over!

specflow will detect "quoted" strings and numbers and pass them as parameters to the code it generates:

specflow in Visual Studio will generate C# code behind the feature files testers create.

[Given(@"I am creating a client with name ""(.*)""")]
public void GivenIAmCreatingAClientWithName(string p0)
{
    // do something with the name "Fred"
}

the feature file

Table parameters:

Scenario: I can log in as different users
	Given the following users exist
        | Username     | Password   |
        | Bob          | bob123     |
        | Alice        | ilovebob   |
        When I am logged in as each user
        Then I can see my profile

The Given step in this scenario receives the data as a Table:

specflow in Visual Studio will generate C# code behind the feature files testers create.

[Given(@"the following users exist")]
public void GivenTheFollowingUsersExist(Table table)
{
    // capture the users so other steps see them
    ScenarioContext.Current.Add("users", table);
}

[Given(@"I can see my profile")]
public void ThenICanSeeMyProfile()
{
    // capture the users so other steps see them
    var table = (Table)ScenarioContext.Current["users"];
}

Further steps load the data from ScenarioContext:

the feature file

Scenario Outline:

Scenario Outline: I can log in as a user
	Given I login with <username> and <password>
        When I view my profile
        Then I can see my avatar
Examples:
        | Username     | Password   |
        | Bob          | bob123     |
        | Alice        | ilovebob   |

specflow in Visual Studio will generate C# code behind the feature files testers create.

A Scenario Outline consists of Scenario Outline and the Example section.

Unlike the Table parameter, this data is available on a row by row basis. The scenario here generates multiple tests.

[When(@"I log in with ""(.*)"" and ""(.*)""")]
public void ILogInWithUsernameAndPassword(string p0, string p1)
{
    // this runs once per row instead
    // p0 is username, p1 is password
}