Cucumber Basics

Cucumber Basics:

There are few terminologies in cucumber. Let's understand them

Feature Files

Feature files are the files which are used to write the test automation steps in Gherkin language. Normally this will be live document. The extension of these files will be .feature.

A Feature file will contain much number of Scenarios. Each scenario represents a test case. In Each Scenario there are Steps which are differentiated by keywords called (GIVEN, WHEN, THEN etc.,)

Feature:

This gives information about the high level business functionality and the purpose of Application under test. Everybody should be able to understand the intent of feature file by reading the first Feature step.

Scenario:

Basically a scenario represents a particular functionality which is under test. By seeing the scenario user should be able to understand what the test is all about. Each scenario should follow given, when and then format. This language is called as “gherkin” language.

·         Given: As we know the meaning of given, it  specifies the precondition.

·         When: This is used when some action is to be performed.

·         Then: The expected outcome or result should be placed here.

·         Background: Whenever any step is required to perform in each scenario then those steps needs to be placed in Background.

·         And: And is used to combine two or more same type of action. i.e., if you have multiple prerequisites, then we have the combine all the GIVEN statement by using "AND" keyword.

Basic template for a FEATURE file:

Feature: <Description of the Feature> Scenario: <Scenario 1>                 Given <Prerequisite>                 When <Actions be be performed>                 Then <Expected Result> Scenario: <Scenario 2>                 Given <Prerequisite>                 When <Actions be be performed>                 Then <Expected Result>

EX:

Feature: Login Functionality Feature                 In order to ensure Login Functionality works,                 I want to run the cucumber test to verify it is working Scenario: Login Functionality                 Given user navigates to www.facebook.com                 When user logs in using Username as “USER” and Password “PASSWORD”                 Then login should be successful

Scenario Outline:

Scenario outlines are used when same test has to be performed with different data set. Ex: if we want to test login functionality with multiple different set of username and password.

Let's take the same example to show the usage of Scenario Outline

Feature: Login Functionality Feature                 In order to ensure Login Functionality works,                 I want to run the cucumber test to verify it is working Scenario Outline: Login Functionality                 Given user navigates to www.facebook.com                 When user logs in using Username as <username> and Password <password>                 Then login should be successful Examples: |username|password| |Suresh|password1| |Naresh|password12|

Observations:

• Column names (username and password) are passed as parameters to WHEN statement.
•  Scenario Outline is used instead of Scenario
• EXAMPLES are used to pass different arguments in tabular format. Vertical pipes are used to separate the columns

Tags:

Cucumber by default runs all scenarios in all the feature files. In real time projects, there could be hundreds of feature file which are not required to run at all times. We can also use multiple tag names for a single feature.

For instance: Feature files related to smoke test need not run all the time. So if you mention a tag as smokeTest in each feature file which is related to smoke test and run cucumber test with @SmokeTest tag. Cucumber will run only those feature files specific to given tags. Please follow the below example. You can specify multiple tags in one feature file.

Let's take the same example to show the usage of Scenario Outline

@SmokeTest @RegressionTest Feature: Login Functionality Feature                 In order to ensure Login Functionality works,                 I want to run the cucumber test to verify it is working Scenario Outline: Login Functionality                 Given user navigates to www.facebook.com                 When user logs in using Username as <username> and Password <password>                 Then login should be successful Examples: |username|password| |Suresh|password1| |Naresh|password12|

Tags can be applied to Scenarios, Please see the example below

@SmokeTest @RegressionTest Feature: Login Functionality Feature                 In order to ensure Login Functionality works,                 I want to run the cucumber test to verify it is working Scenario Outline: Login Success Functionality                 Given user navigates to www.facebook.com                 When user logs in using Username as <username> and Password <password>                 Then login should be successful Examples: |username|password| |Suresh|password1| |Naresh|password12| @SmokeTest Scenario Outline: Login Failure Functionality                 Given user navigates to www.facebook.com                 When user logs in using Username as <username> and Password <password>                 Then login should be successful Examples: |username|password| |Rajesh|password1| |Mahesh|password12|

Observation: 

• Suppose you want to execute the scenarios/features which are in Regression Suite, then the Junit Runner will execute only "Login Success Functionality" Scenario
• Suppose you want to execute the scenarios/features which are in Smoke Suite, then the Junit Runner will execute only "Login Success Functionality" and "Login Failure Functionality" Scenarios

Junit Runner:

Cucumber Runner / JUNIT Runner Class is the class, which is used to get all the feature files in the specified location.

The Basic Template of Junit Runner is  as follows:

@RunWith(Cucumber.class)   @CucumberOptions (                 format(deprecated)/plugin={"pretty","json:target"} ,                 features = {"src/java/features/"}                 ) public class Runner { }

Observations:

• Cucumber.class : Whenever we run anything as part of cucumber it iwll run using the cucumber.class file
• CucumberOptions: it is used to provide some additional inputs like, format, feature files location and tags

Example:

@RunWith(Cucumber.class)   @CucumberOptions (                 format(deprecated)/plugin={"pretty","json:target"} ,                 features = {"src/java/features/"},                 tags={"@SmokeTest", "@RegressionTest"}                 ) public class Runner { }

Note: To run the specific feature file cucumber uses standard Junit Runner and specify tags in @Cucumber. Options(Deprecated)/@CucumberOptions. Multiple tags can be given by using comma separate. Here you can specify the path of the report and type of report you want to generate.

If you run this Runner file, all the Scenarios/features under SmokeTest/RegressionTest will be executed and the result be generated in JSON format.

Trouble Shootings:

If you get the Invocation Target Exception, then you have to remove Cucumber-spring.jar from the build path

If you ran the feature file but it threw an error like this:                 Exception in thread "main" cucumber.runtime.CucumberException: Unknown option: --plugin                  at cucumber.runtime.RuntimeOptions.parse(RuntimeOptions.java:119)                  at cucumber.runtime.RuntimeOptions.<init>(RuntimeOptions.java:50)                   then you have to update the jar files to latest version

If you are not able to import the "@Cucumber.Options" and it is throwing error, the use "@CucumberOptions" instead of "@Cucumber.Options" (Deprecated)

If you are getting the below exception Exception in thread "main" Usage: java cucumber.api.cli.Main [options] [ [FILE|DIR][:LINE[:LINE]*] ]+ Then use the version 1.2.4 for cucumber-Java, Cucumber-Junit and Cucumber-core jars. user version 2.12.2 for gherkin                 change the code as below:                                 @CucumberOptions(                                  plugin = {"pretty","jason:Target/"},                                  features = {"src/Cucumber/"}                                 )