How to retrive #Test method parameters in #DataProvider method? - testing

Question

I would like to retrieve parameters name of Test method in DataProvider method.
By using method.getParameterTypes() in DataProvider, I am able to get the class of param being passed in Test method, but I want the names.
#Test
public void TC_001(String userName, String passWord){
//code goes here
}
#DataProvider
public Object[][] testData(Method method){
//Here I want to get names of param of test method i.e. userName and passWord
}
This is required because using these names I can get the data from my Excel file

Answer 1

You can use reflection to get the parameters from the method to get the parameter names.
#DataProvider
public Object[][] testData(Method method){
String arg0 = method.getParameters()[0].getName();
// should be "userName" in your example test case
}
Note that the classes have to be compiled with -g:vars to include the parameter names in the debug information. Otherwise parameter names are named arg0, arg1, ... It appears that with the OpenJDK 8 this is the default.
To be less dependant on that fact and to avoid possible name confusion/conflicts I'd use a (custom) annotation that specifies the argument name:
Define an annotation:
#Retention(RUNTIME)
#Target(PARAMETER)
public #interface ParamName {
public String value();
}
Use it:
public void TC_001(#ParamName("username") String userName, String passWord) { ... }
Access the name:
Parameter parameter = method.getParameters()[0];
ParamName parameterNameAnn = parameter[0].getAnnotation(ParamName.class);
String parameterName;
if (parameterNameAnn != null) {
// get the annotated name
parameterName = parameterNameAnn.value();
} else {
// annotation missing, resort to the "reflected" name
parameterName = parameter.getName();
}
See also
Reflection Tutorial (Oracle)
Especially Parameter Reflection (Oracle)
Compiler options (Oracle)
Annotation Tutorial (Oracle)