how to cover the Parameterized method in test class

Question

for eg private static test(color c)

Answer 1

One problem is that your method is declared as private which means other classes can't access it. This includes Unit Tests. There's a few ways around this. You could:

• Declare the method as public
• Call instead a public method that calls the private one
• Use the @TestVisible annotation

As @Mahmood mentioned in the comments:

It is accepting a workbook object. You need to first create a workbook object and then call your method and pass it on.

So, to cover this class you could do something as simple as creating a new Workbook object and calling it (working under the assumption you've changed private to public or another workaround):

@isTest static void test_method_one() {
    Workbook wrkbk = new Workbook(
        // Assign fields values here...
    );

    INSERT wrkbk;

    myClassThatContainsTheMethod.processActionPlan(wrkbk);
}

That would start covering code, but you're going to have to create multiple instances of Workbook objects that match each case if your long if/then statements.

For instance, your first if/then statement is:

if(sheet.sheet.contains('Action Plan')) {

Thus you need to ensure that your sheet.sheet contains the String "Action Plan". If you don't do this, you'll find that a very small percentage of the method is covered because if as in this case it doesn't match "Action Plan" it'll skip everything inside and continue on. In this instance, to the end of the method.

I strongly advise looking over some Trailhead modules on Unit Testing. In a nutshell, think of it as programatically executing your classes and methods and asserting that the value returned does what you expect.

For instance, if you have a class like below:

public class Example {
    public static Integer addNumbers(Integer x, Integer y) {
        return x + y;
    }
}

Your unit test might look something like this:

@isTest static void test_method_one() {
    Integer a = 10, b = 17; // Create two numbers to add together
    Integer result = Example.AddNumbers(a, b); // Call the class and the method and assign it to another variable

    System.assertEquals(27, result); // We know 10 + 17 = 27, so that's what we expect. If `result` returns something different, we know there's a problem and the test will fail
}

Answer 2

Private methods are not visible in Test Classes. Hence use @TestVisible annotation so that the method is accessible for running tests only. Use as shown below.

@TestVisible private static void processActionPlan(Workbook workbook) {

your code 

}

Refer this link TestVisible Annotation for further details.