In this tutorial, we will create some tests in Cucumber using Java.
Cucumber is mainly a collaboration framework used in BDD context in order to improve shared understanding within the team, usually during "3 Amigos" sessions. That's its main fit.
However, some teams use it in other contexts (e.g. after sofware has being built) for implementing automated tests and take advantage of Gherkin syntax to have visibility/abstraction of the underlying automation code and have reusable automation code.
(Test) Scenarios derived from Cucumber are executable specifications; their statements will have a corresponding code implementation. These test scenarios are feature and more business oriented; they're not unit/integration tests.
Your specification is made using Gherkin (i.e. Given, When, That) statements in Scenario(s) or Scenario Outline(s), eventually complemented with a Background. Implementation of each Gherkin statement (i.e. "step") is done in code; the Cucumber framework finds the code based on a regular or cucumber expression.
Cucumber is used in diverse scenarios. Next you may find some usage patterns, even though Cucumber usage is mostly recommended only if you are adopting BDD.
You may be adopting, or aiming to, one of the previous patterns.
Before moving into the actual implementation, we need to decide which workflow we'll use: do we want to use Xray/Jira as the master for writing the declarative specification (i.e. the Gherkin based Scenarios), or do we want to manage those outside using some editor and store them in Git, for example?
Please see Testing in BDD with Gherkin based frameworks (e.g. Cucumber) for an overview of the possible workflows. The place that you'll use to edit the Cucumber Scenarios will affect your workflow. There are teams that prefer to edit Cucumber Scenarios in Jira using Xray, while there others that prefer to edit them by writing the .feature files by hand using some IDE. |
For the purpose of this tutorial, we'll use a simple, dummy Calculator implemented in a Java class as our target for testing.
package com.xray.tutorials;
public class Calculator
{
// Square function
public static int Square(int num)
{
return num*num;
}
// Add two integers and returns the sum
public static int Add(int num1, int num2 )
{
return num1 + num2;
}
// Add two integers and returns the sum
public static double Add(double num1, double num2 )
{
return num1 + num2;
}
// Multiply two integers and retuns the result
public static int Multiply(int num1, int num2 )
{
if ((num1==1) || (num2==1)) {
return 0;
} else {
return num1 * num2;
}
}
public static int Divide(int num1, int num2 )
{
return num1 / num2;
}
// Subtracts small number from big number
public static int Subtract(int num1, int num2 )
{
if ( num1 > num2 )
{
return num1 - num2;
}
return num2 - num1;
}
} |
This section assumes using Xray as master, i.e. the place that you'll be using to edit the specifications (e.g. the scenarios that are part of .feature files).
The overall flow would be something like this, assuming Git as the source code versioning system:
Note that steps (5-9) performed by the CI tool are all automated, obviously.
To generate .feature file(s) based on Scenarios defined in Jira (i.e. Cucumber Tests and Preconditions), we can do it directly from Jira, by the REST API or using a CI tool; we'll see that ahead in more detail.
All starts with a user story or some sort of “requirement” that you wish to validate. This is materialized as a Jira issue and identified by the corresponding issue key (e.g. CALC-7931).
We can promptly check that it is “UNCOVERED” (i.e. that it has no tests covering it, no matter their type/approach).
In this case, we'll create a Cucumber Test, of Cucumber Type "Scenario".
We can fill out the Gherkin statements immediately on the Jira issue create dialog or we can create the Test issue first and fill out the details on the next screen, from within the Test issue. In the latter case, we can take advantage of the built-in Gherkin editor which provides auto-complete of Gherkin steps.
After the Test is created it will impact the coverage of related "requirement", if any.
The coverage and the test results can be tracked in the "requirement" side (e.g. user story). In this case, you may see that coverage changed from being UNCOVERED to NOTRUN (i.e. covered and with at least one test not run).
Additional tests could be created, eventually linked to the same Story or linked to another one (e.g. multiplication).
The related statement's code is managed outside of Jira and stored in Git, for example.
The tests related code is stored under src/test directory, which itself contains several other directories. In this case, they're organized as follows:
cypress/integration/common: step implementation files, in JavaScript.The steps "glue-code" is defined in a class.
package calculator;
import io.cucumber.java.en.Given;
import io.cucumber.java.en.Then;
import io.cucumber.java.en.When;
import com.xray.tutorials.Calculator;
import static org.junit.Assert.*;
public class StepDefinitions {
private Integer int1;
private Integer int2;
private Integer result;
@Given("I have entered {int} into the calculator")
public void i_have_entered_into_the_calculator(Integer int1) {
this.int2 = this.int1;
this.int1 = int1;
}
@When("I press add")
public void i_press_add() {
this.result = Calculator.Add(this.int1, this.int2);
}
@When("I press multiply")
public void i_press_multiply() {
this.result = Calculator.Multiply(this.int1, this.int2);
}
@Then("the result should be {int} on the screen")
public void the_result_should_be_on_the_screen(Integer int1) {
// Write code here that turns the phrase above into concrete actions
assertEquals((Integer)(this.int1 + this.int2), this.result);
}
}
|
You can then export the specification of the test to a Cucumber .feature file via the REST API, or the Export to Cucumber UI action from within the Test/Test Execution issue or even based on an existing saved filter. A plugin for your CI tool of choice can be used to ease this task.
So, you can either:
|
We will use the code from the Github repository "cucumber-java-skeleton", with slight changes in order to make the dummy Test pass.
The first step is to create a Cucumber Test, of Cucumber Type "Scenario", in Jira. The specification would be exactly the same as the one provided in the original repository.
After creating the Test in Jira and associating it with requirements, etc., you can export the specification of the test to a Cucumber .feature file via the REST API or the Export to Cucumber UI action from within the Test Execution issue.
The created file will be similar to the original, but will contain the references to the Test issue key and the covered requirement issue key.
@ABC-100
Feature: Belly
@ABC-122
Scenario: a few cukes
Given I have 42 cukes in my belly
When I wait 1 hour
Then my belly should growl |
You can change the implementation of the steps in order to make them pass quickly.
package skeleton;
import cucumber.api.java.en.Given;
import cucumber.api.java.en.Then;
import cucumber.api.java.en.When;
public class Stepdefs {
@Given("^I have (\\d+) cukes in my belly$")
public void I_have_cukes_in_my_belly(int cukes) throws Throwable {
Belly belly = new Belly();
belly.eat(cukes);
}
@When("^I wait (\\d+) hour$")
public void I_wait_hours(int hours) throws Throwable {
Thread.sleep(hours*0);
}
@Then("^my belly should growl$")
public boolean my_belly_should_growl() throws Throwable {
return true;
}
} |
After running the tests and generating the Cucumber JSON report (e.g., data.json), it can be imported to Xray via the REST API or the Import Execution Results action within the Test Execution.
mvn compile test -Dcucumber.options="-p json:data.json" |
The execution screen details will provide information on the test run result.
The Cucumber Scenarios Example/Result details (i.e., Hooks, Backgrounds and Steps) are only available for executions done in Xray v2.2.0 and above. |
The icon |
Please see Testing in BDD with Gherkin based frameworks (e.g. Cucumber) for an overview on how to use Cucumber Tests with Xray. |
represents the evidences ("embeddings") for each Hook, Background and Steps.