自定义类数组作为TestNG中的@DataProvider

Question

I wanted to know if there is a way to package all parameters to a @Test method into one class Name and provide Name[] as the @DataProvider ?

public class FirstTestClass {

  @Test (dataProvider = "getNames")
  public void test01(Name name) {
    System.out.println(name.name + " " + name.id);
  }
  @DataProvider
  public Name[] getNames() {
      Name[] result = new Name[2];
      result[0] = new Name("john", 5);
      result[1] = new Name("doe", 4);
      return result;
  }
}

class Name {
    public String name;
    public Integer id;
    public Name(String name, Integer id) {
        this.name = name;
        this.id = id;
   }
}

The test is getting skipped and I get a message saying must return either Object[][] or Iterator<>[] . This is kind of limited right? Any workaround for this?

Answer 1

Why are you not able to do the same thing using two dimensional array with only 1 column. Is there any specific requirement that you have? Something like this

@Test(dataProvider = "getNames")
public void test01(Name name) {
    System.out.println(name.name + " " + name.id);
}

@DataProvider
public Object[][] getNames() {
    Name[][] result = new Name[2][1];
    result[0][0] = new Name("john", 5);
    result[1][0] = new Name("doe", 4);
    return result;
}

I tested your code with the change I am suggesting it works just fine.

Answer 2

Change it to

@DataProvider
public Name[][] getNames() {
   Name[][] result = new Name[2][];
   result[0] = {new Name("john", 5)};
   result[1] = {new Name("doe", 4)};
   return result;
}

Answer 3

I don't know why you use a dedicated class to hold all attributes, but you should consider something like:

public class FirstTestClass {

  @Test(dataProvider = "getNames")
  public void test01(String name, Integer id) {
    System.out.println(name + " " + id);
  }

  @DataProvider
  public Object[][] getNames() {
    return new Object[][] {
      new Object[] { "john", 5 },
      new Object[] { "doe", 4 }
    }
  }
}

Answer 4

In JUnit 4.x, the following is the way to achieve the above scenario.

@RunWith(Parameterized.class)
public class FirstTest {
    private LoginCredentials loginData;

    public FirstTest(LoginCredentials testData) {
        loginData = testData;
    }

@Parameterized.Parameters
public static LoginCredentials[] generateTestData() {
    return ReadingExcelSheets.generateTestData();
}

I was hoping for something similar in TestNG, which I was told is more flexible and powerful than JUnit. Turns out, we have return only Object[][] in the @DataProvider method.

Answer 5

As I understand your question now, you'd like a TestNG translation of:

@RunWith(Parameterized.class)
public class FirstTest {
    private LoginCredentials loginData;

    public FirstTest(LoginCredentials testData) {
        loginData = testData;
    }

    @Parameterized.Parameters
    public static LoginCredentials[] generateTestData() {
        return ReadingExcelSheets.generateTestData();
    }
}

A solution could be:

public class FirstTest {

    private final LoginCredentials loginData;

    @Factory(dataprovider = "generateTestData")
    public FirstTest(LoginCredentials testData) {
        loginData = testData;
    }

    @Test
    public void test01() {
        System.out.println(loginData);
    }

    @DataProvider
    public static Object[][] generateTestData() {
        return convert(ReadingExcelSheets.generateTestData());
    }

    public static Object[][] convert(LoginCredentials[] values) {
        Object[][] result = new Object[values.length];
        for (int i=0; i<result.length; i++) {
            result[i] = new Object[]{ values[i] };
        }
        return result;
    }
}

Or

public class FirstTest {

    @Test(dataprovider = "generateTestData")
    public void test01(LoginCredentials loginData) {
        System.out.println(loginData);
    }

    @DataProvider
    public static Object[][] generateTestData() {
        return convert(ReadingExcelSheets.generateTestData());
    }

    public static Object[][] convert(LoginCredentials[] values) {
        Object[][] result = new Object[values.length];
        for (int i=0; i<result.length; i++) {
            result[i] = new Object[]{ values[i] };
        }
        return result;
    }
}

But ok, TestNG could provide the convert method itself and/or manage Object[] as a valid return type out-of-the-box.

Feel free to propose a patch on http://github.com/cbeust/testng Help is always welcome :)