使用不同的数据提供程序在TestNG中重复整个测试类

Question

I use TestNG and I would like to run different times the same test and each time use specific data providers which will be used in a subset of test methods, in other words I would like to run the test class with different data without change the test itself.

I have got a problem creating the factory for the test class, here is my case:

@Test
public class MyTest {

    @Factory
    public Object[] createInstances() {
        DataTest dataTest_1 = new DataTest("foo", true);
        DataTest dataTest_2 = new DataTest("FOO", false);

        Object[] result = new Object[]{
                new MyTest(dataTest_1);
                new MyTest(dataTest_2)
        };
        return result;
    }

    private final DataTest dataTest;

    public MyTest(DataTest dataTest) {
        this.dataTest = dataTest;
    }   
}

Error:

Configuring TestNG with: org.apache.maven.surefire.testng.conf.TestNGMapConfigurator@18e8568
org.apache.maven.surefire.util.SurefireReflectionException: java.lang.reflect.InvocationTargetException; nested exception is java.lang.reflect.InvocationTargetException: null
java.lang.reflect.InvocationTargetException
        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:483)
        at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
        at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
        at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
        at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
        at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: org.testng.TestNGException:
The factory method class MyTest.createInstances() threw an exception
        at org.testng.internal.FactoryMethod.invoke(FactoryMethod.java:92)
        at org.testng.internal.TestNGClassFinder.<init>(TestNGClassFinder.java:140)
        at org.testng.TestRunner.initMethods(TestRunner.java:405)
        at org.testng.TestRunner.init(TestRunner.java:231)
        at org.testng.TestRunner.init(TestRunner.java:201)
        at org.testng.TestRunner.<init>(TestRunner.java:150)
        at org.testng.SuiteRunner$DefaultTestRunnerFactory.newTestRunner(SuiteRunner.java:523)
        at org.testng.SuiteRunner.init(SuiteRunner.java:157)
        at org.testng.SuiteRunner.<init>(SuiteRunner.java:111)
        at org.testng.TestNG.createSuiteRunner(TestNG.java:1212)
        at org.testng.TestNG.createSuiteRunners(TestNG.java:1199)
        at org.testng.TestNG.runSuitesLocally(TestNG.java:1053)
        at org.testng.TestNG.run(TestNG.java:974)
        at org.apache.maven.surefire.testng.TestNGExecutor.run(TestNGExecutor.java:77)
        at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.execute(TestNGDirectoryTestSuite.java:110)
        at org.apache.maven.surefire.testng.TestNGProvider.invoke(TestNGProvider.java:106)
        ... 9 more
Caused by: java.lang.NullPointerException
        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:483)
        at org.testng.internal.FactoryMethod.invoke(FactoryMethod.java:80)
        ... 24 more

Moreover, DataTest component at the moment contains two parameters but it will contains much more parameters - to define the expected values - and a collection of data providers.

Eventually, if I use a String as parameter of the test class - just as a attempt - the test runs.

Answer 1

The problem is that you cannot instantiate a new instance of MyTest in order to call createInstances . So it becomes a chicken and egg problem. If you declare createInstances as a static method, it should work.