How to execute cucumber feature file parallel

By | December 31, 2017
Questions:

I have below feature files (Separate feature files) in src/test/resources/feature/ and I would like to run them in parallel. Like: One feature file has to execute in chrome and another one has to execute in firefox as mentioned @Tags name.

Feature: Refund item

@chrome
  Scenario: Jeff returns a faulty microwave
    Given Jeff has bought a microwave for $100
    And he has a receipt
    When he returns the microwave
    Then Jeff should be refunded $100

Feature: Refund Money

@firefox
  Scenario: Jeff returns the money
    Given Jeff has bought a microwave for $100
    And he has a receipt
    When he returns the microwave
    Then Jeff should be refunded $100

Can somebody assist me to achieve this.I’m using cucumber-java 1.2.2 version, and AbstractTestNGCucumberTests using as runner. Also, let me know how can I create a Test Runner dynamically by using feature files and make them run in parallel.

Answers:

Cucumber does not support parallel execution out of the box.
I’ve tried, but it is not friendly.

  1. We have to use maven’s capability to invoke it in parallel. Refer link
  2. Also there is a github project which uses custom plugin to execute in parallel.
    Refer cucumber-jvm-parallel-plugin
Questions:
Answers:

Update: 4.0.0 version is available at maven central repository with bunch of changes.for more details go here.

Update: 2.2.0 version is available at maven central repository.

You can use opensource plugin cucumber-jvm-parallel-plugin which has many advantages over existing solutions. Available at maven repository

   <dependency>
     <groupId>com.github.temyers</groupId>
     <artifactId>cucumber-jvm-parallel-plugin</artifactId>
     <version>2.1.0</version>
   </dependency>
  1. First you need to add this plugin with required configuration in your project pom file.

    <plugin>
      <groupId>com.github.temyers</groupId>
      <artifactId>cucumber-jvm-parallel-plugin</artifactId>
      <version>2.1.0</version>
      <executions>
         <execution>
         <id>generateRunners</id>
         <phase>generate-test-sources</phase>
         <goals>
           <goal>generateRunners</goal>
         </goals>
         <configuration>
             <!-- Mandatory -->
             <!-- comma separated list of package names to scan for glue code -->
             <glue>foo, bar</glue>
             <outputDirectory>${project.build.directory}/generated-test-sources/cucumber</outputDirectory>
              <!-- The directory, which must be in the root of the runtime classpath, containing your feature files.  -->
               <featuresDirectory>src/test/resources/features/</featuresDirectory>
              <!-- Directory where the cucumber report files shall be written  -->
              <cucumberOutputDir>target/cucumber-parallel</cucumberOutputDir>
              <!-- comma separated list of output formats json,html,rerun.txt -->
              <format>json</format>
              <!-- CucumberOptions.strict property -->
              <strict>true</strict>
              <!-- CucumberOptions.monochrome property -->
              <monochrome>true</monochrome>
              <!-- The tags to run, maps to CucumberOptions.tags property you can pass ANDed tags like "@tag1","@tag2" and ORed tags like "@tag1,@tag2,@tag3" -->
             <tags></tags>
             <!-- If set to true, only feature files containing the required tags shall be generated. -->
             <filterFeaturesByTags>false</filterFeaturesByTags>
             <!-- Generate TestNG runners instead of default JUnit ones. --> 
             <useTestNG>false</useTestNG>
             <!-- The naming scheme to use for the generated test classes.  One of 'simple' or 'feature-title' --> 
            <namingScheme>simple</namingScheme>
            <!-- The class naming pattern to use.  Only required/used if naming scheme is 'pattern'.-->
            <namingPattern>Parallel{c}IT</namingPattern>
            <!-- One of [SCENARIO, FEATURE]. SCENARIO generates one runner per scenario.  FEATURE generates a runner per feature. -->
            <parallelScheme>SCENARIO</parallelScheme>
            <!-- This is optional, required only if you want to specify a custom template for the generated sources (this is a relative path) -->
            <customVmTemplate>src/test/resources/cucumber-custom-runner.vm</customVmTemplate>
            </configuration>
           </execution>
         </executions>
       </plugin>
    
  2. Now add below plugin just below above plugin which will invoke runner classes generated by above plugin

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <configuration> 
                <forkCount>5</forkCount>
                <reuseForks>true</reuseForks>
                <includes>
                    <include>**/*IT.class</include>
                </includes>
            </configuration>
        </plugin>
    
  3. Above two plugins will do magic for cucumber test running in parallel (provided you machine also have advanced hardware support).

  4. Strictly provided <forkCount>n</forkCount> here ‘n’ is directly proportional to 1) Advanced Hardware support and 2) you available nodes i.e. registered browser instances to HUB.

  5. One major and most important changes is your WebDriver class must be SHARED and you should not implement driver.quit() method, as closing is take care by shutdown hook.

    import cucumber.api.Scenario;
    import cucumber.api.java.After;
    import cucumber.api.java.Before;
    import org.openqa.selenium.OutputType;
    import org.openqa.selenium.WebDriver;
    import org.openqa.selenium.WebDriverException;
    import org.openqa.selenium.firefox.FirefoxDriver;
    import org.openqa.selenium.support.events.EventFiringWebDriver;
    
    public class SharedDriver extends EventFiringWebDriver {
        private static WebDriver REAL_DRIVER = null;
    
    
    
        private static final Thread CLOSE_THREAD = new Thread() {
            @Override
            public void run() {
                REAL_DRIVER.close();
            }
        };
    
        static {
            Runtime.getRuntime().addShutdownHook(CLOSE_THREAD);
        }
    
        public SharedDriver() {
            super(CreateDriver());
        }
    
        public static WebDriver CreateDriver() {
            WebDriver webDriver;
            if (REAL_DRIVER == null)
                webDriver = new FirefoxDriver();
            setWebDriver(webDriver);
            return webDriver;
        }
    
        public static void setWebDriver(WebDriver webDriver) {
            this.REAL_DRIVER = webDriver;
        }
    
        public static WebDriver getWebDriver() {
            return this.REAL_DRIVER;
        }
    
        @Override
        public void close() {
            if (Thread.currentThread() != CLOSE_THREAD) {
                throw new UnsupportedOperationException("You shouldn't close this WebDriver. It's shared and will close when the JVM exits.");
            }
            super.close();
        }
    
        @Before
        public void deleteAllCookies() {
            manage().deleteAllCookies();
        }
    
        @After
        public void embedScreenshot(Scenario scenario) {
            try {
                byte[] screenshot = getScreenshotAs(OutputType.BYTES);
                scenario.embed(screenshot, "image/png");
            } catch (WebDriverException somePlatformsDontSupportScreenshots) {
                System.err.println(somePlatformsDontSupportScreenshots.getMessage());
            }
        }
    }
    
  6. Considering you want to execute more than 50 threads i.e. same no of browser instances are registered to HUB but Hub will die if it doesn’t get enough memory therefore to avoid this critical situation you should start hub with -DPOOL_MAX=512 (or larger) as stated in grid2 documentation.

    Really large (>50 node) Hub installations may need to increase the jetty threads by setting -DPOOL_MAX=512 (or larger) on the java command line.

    java -jar selenium-server-standalone-<version>.jar -role hub -DPOOL_MAX=512

Questions:
Answers:

If all you are expecting is to be able to run multiple features in parallel, then you can try doing the following :

  • Duplicate the class AbstractTestNGCucumberTests in your test project and set the attribute parallel=true to the @DataProvider annotated method.

Since the default dataprovider-thread-count from TestNG is 10 and now that you have instructed TestNG to run features in parallel, you should start seeing your feature files get executed in parallel.

But I understand that Cucumber reporting is inherently not thread safe, so your reports may appear garbled.

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