Hello Folks,
TestNG provides a built in mechanism to re-run failed test case for N times (Ideally) instantly using IRetryAnalyzer interface. It means that if a test method fails, we can rerun it for N times or until it is passed during run. Let’s see this concept in more details:
IRetryAnalyzer Interface:
IRetryAnalyzer is an interface in org.testng package. It has only method named retry. By overriding this method in your class, you can control the number of attempts to rerun a failed test case. You can refer code of IRetryAnalyzer below:
package org.testng; /** * Interface to implement to be able to have a chance to retry a failed test. * * @author [email protected] (Jeremie Lenfant-Engelmann) * */ public interface IRetryAnalyzer { /** * Returns true if the test method has to be retried, false otherwise. * * @param result The result of the test method that just ran. * @return true if the test method has to be retried, false otherwise. */ public boolean retry(ITestResult result); }
When a @Test annotated method has value for “retryAnalyzer” attribute, reTry method will be called only if Test method is failed. “retry” method will not be executed at all if Test method is passed or skipped.
How to implement above mechanism?
Since IRetryAnalyzer is an interface, we must have to implement it in our class to provide definition to “retry” method. You can implement this interface in any normal class or TestNG class. If you keep a separate implemented class, it will be good for best readability and maintain. So, let’s create a class and implement IRetryAnalyzer interface.
package RetryAnalyzer;
import org.testng.IRetryAnalyzer;
import org.testng.ITestResult;
public class RetrySetup implements IRetryAnalyzer{
// Variable to keep counter of retry
private int retryCount = 0;
// Variable to define max retry count
private static final int maxRetryCount = 3;
@Override
public boolean retry(ITestResult result) {
// We need to implement a cap, otherwise execution might go indefinite loop.
if(retryCount < maxRetryCount)
{
retryCount++;
System.out.println("Retrying Test method : "+result.getName() + " for " + retryCount +" times. ");
return true;
}
return false;
}
}
Now, you need to add an attribute called “retryAnalyzer” to @Test annotated method with value as Implemented class name. If we do not add this attribute, remember “retry” will not be called automatically. It provides you flexibility of trying to rerun those test method which fails sometimes because of some random issues (not functional) only.
package RetryAnalyzer;
import org.testng.Assert;
import org.testng.annotations.Test;
public class RetryTest {
// Need to mention implemented class name of IRetryAnalyzer
@Test(retryAnalyzer= RetrySetup.class)
public void method1()
{
System.out.println("Failing method purposefully.");
Assert.fail("Purposefully failing");
}
}
Execution flow:
- “method1” will be run and it will fail as we are failing it wantedly.
- Then control will go to retry method of “RetrySetup class as @Test annotation has “retryAnalyzer attribute.
- Since retryCount < maxRetryCount (0 < 3), retry will return true and retryCount counter will be increased by one. “method1” will be executed again. Earlier run will be marked as skipped.
- Same flow will be repeated till ( retryCount < maxRetryCount) becomes false and finally “method1” will be marked as failed.
Output:
[java] [RemoteTestNG] detected TestNG version 6.14.3 Failing method purposefully. Retrying Test method : method1 for 1 times. Failing method purposefully. Retrying Test method : method1 for 2 times. Failing method purposefully. Retrying Test method : method1 for 3 times. Failing method purposefully. FAILED: method1 java.lang.AssertionError: Purposefully failing at org.testng.Assert.fail(Assert.java:96) at RetryAnalyzer.RetryTest.method1(RetryTest.java:13) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:124) at org.testng.internal.Invoker.invokeMethod(Invoker.java:583) at org.testng.internal.Invoker.retryFailed(Invoker.java:839) at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1010) at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125) at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109) at org.testng.TestRunner.privateRun(TestRunner.java:648) at org.testng.TestRunner.run(TestRunner.java:505) at org.testng.SuiteRunner.runTest(SuiteRunner.java:455) at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:450) at org.testng.SuiteRunner.privateRun(SuiteRunner.java:415) at org.testng.SuiteRunner.run(SuiteRunner.java:364) at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52) at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:84) at org.testng.TestNG.runSuitesSequentially(TestNG.java:1208) at org.testng.TestNG.runSuitesLocally(TestNG.java:1137) at org.testng.TestNG.runSuites(TestNG.java:1049) at org.testng.TestNG.run(TestNG.java:1017) at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114) at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)