Parameterized testing

Figure 336. Parameterized tests

Separate both test parameters and expected values from code.
Provide parameter values either by variables or by separate CSV files.
Read Parameterized Classes and Tests for details.

Figure 337. CSV parameter testing

Hard-coded	public void testPrimes() { Assertions.assertEquals(false, Prime.isPrime(1)); Assertions.assertEquals(true, Prime.isPrime(2)); Assertions.assertEquals(true, Prime.isPrime(3)); Assertions.assertEquals(false, Prime.isPrime(4));}
Parameterized	@ParameterizedTest @CsvSource( textBlock = """ false, 1 true, 2 true, 3 false, 4""") public void testPrimes(boolean expected, int primeCandidate) { Assertions.assertEquals(expected, Prime.isPrime(primeCandidate)); }

Hard-coded

public void testPrimes() {
  Assertions.assertEquals(false, Prime.isPrime(1));
  Assertions.assertEquals(true,  Prime.isPrime(2));
  Assertions.assertEquals(true,  Prime.isPrime(3));
  Assertions.assertEquals(false, Prime.isPrime(4));}

Parameterized

@ParameterizedTest
@CsvSource( textBlock = """
   false, 1
   true,  2
   true,  3
   false, 4""")
public void testPrimes(boolean expected, int primeCandidate) {
  Assertions.assertEquals(expected, Prime.isPrime(primeCandidate));         
}

Figure 338. CSV parameter testing results

mvn test ─ de.hdm_stuttgart.mi.sd1.PrimeTest - 0.098 s
           ├─ ✔ testPrimes(int, boolean)[1] 1, false - 0.035 s
           ├─ ✔ testPrimes(int, boolean)[2] 2, true - 0.001 s
           ├─ ✔ testPrimes(int, boolean)[3] 3, true - 0.001 s
           └─ ✔ testPrimes(int, boolean)[4] 4, false - 0.001 s

Figure 339. CSV parameter file based testing

@ParameterizedTest
@CsvFileSource(resources = "/primes.csv")
public void testPrimesByFile 
  (boolean expected, int primeCandidate, ) {
     Assertions.assertEquals(
        expected
       ,Prime.isPrime(primeCandidate)
     );
}

File test/resources/primes.csv:

false, 1
true,  2
true,  3
false, 4

mvn test ─ de.hdm_stuttgart.mi.sd1.PrimeTest - 0.098 s
           ├─ ✔ testPrimesByFile(int, boolean)[1] false, 1  - 0.031 s
           ├─ ✔ testPrimesByFile(int, boolean)[2] true,  2 - 0.001 s
           ├─ ✔ testPrimesByFile(int, boolean)[3] true,  3 - 0.001 s
           └─ ✔ testPrimesByFile(int, boolean)[4] false, 4 - 0.001 s

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