Test Smell: it is not a good practice to use the loop in the test

[TestSmell]

Hi!

We notice that you use the loop structure in your test cases.
For example, testInvalidChar() in NoiseCharactersTest.java

However, using the loop in test cases is not a good test practice.

We analyzed the relevant Stack Overflow posts and summarized four potential negatives it brings:

1. Loops make the test case more complex.
2. In most cases, a loop can be replaced with a data-driven test that is more readable.
3. Loops break the assert-for-one-thing thumb rule. I don't mean a single assert statement.
4. When a test fails, knowing the reason is more complicated.

Solution:
To avoid using the loop in the test, JUnit provides an annotation (i.e., @ParameteredTest), which can enable a test case to run multiple times with different parameters.
Therefore, the code can be refactored as:

@test
@ParameteredTest
@@valuesource(invalidPatterns = {"", "1", "ABC", "\u21", "#x0001-#x0000"
, "#x0001 - #x - #x0000", "#x0000 #x0022"})
public void testInvalidChar(String i) {
assertThrows(IllegalArgumentException.class, () -> {
myFilter.add(i);
});
}

[jamesagnew]

This could probably be replaced with a parameterized test, and a PR implementing that would be accepted.