Before answer this question we have to answer the question what is classic unit test?
- Classic unit test
Classic or closed unit test is the normal unit test that doesn't take parameter and depend on static data inside the method itself, using traditional unit tests that do not take inputs lead that you have to write many tests to cover all possible inputs
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[TestMethod]
public void MyTestMethod()
{
int x = 5;
int y = 10;
}
- Parameterized unit test
Parameterized unit tests are test methods with parameters. A straightforward extension is to allow parameters, which serve as the test input. The result is a parameterized unit test
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[TestMethod]
public void MyTestMethod(int x, int y)
{
}
So classic unit tests are methods without parameters, parameterized unit tests are methods with parameters. So you can use it with Data driven test from DB or Excel sheet, or you can use it with many inputs as needed You can partition parameterized unit tests into four parts:
- Assume: Assume preconditions over the test inputs.
- Arrange: Set up the unit under test-determine which parameters are used to shape legal test inputs.
- Act: Exercise the unit under test by adding a method sequence, which specifies a scenario, and capturing any resulting state. You use parameters for argument values when calling other methods in the Act stage.
- Assert: Verify the behavior by adding assertions that encode the rules of a unit test.
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[PexMethod]
public void ContainsNumbers(string number, Employee employee, [PexAssumeNotNull] string value)
{
PexAssume.IsTrue(employee != null);
PexAssert.TrueForAll(number, delegate(char c)
{
return char.IsDigit(c);
});
}