Unit Test Correctness vs Coverage, mana yang lebih penting?

basic-multiply-test-correct.md

test('2 multiply 3 is equal to 6', (int a, int b) {
    // Arrange
    const a = 2;
    const b = 3;    

    // Act
    final answer = multiply(a, b);

    // Assert
    expect(answer, 6);
});

basic-multiply-test-with-faker.md

test('a multiply b is equal to a * b', (int a, int b) {
    // Arrange
    const a = faker.datatype.number();
    const b = faker.datatype.number();

    // Act
    final answer = multiply(a, b);

    // Assert
    expect(answer, a * b);
});

basic-multiply-test-wrong.md

test('multiply is correct', (int a, int b) {
    // Arrange
    const a = 2;
    const b = 3;

    // Act
    final answer = multiply(a, b);

    // Assert
    expect(a, greaterThan(0));
});

basic-multiply-wrong.md

int multiply (int a, int b) {
    return 6;
}

basic-multiply.md

int multiply (int a, int b) {
    return a * b;
}

complex-multiply-test-with-negative.md

test('2 multiply 3 is equal to 6', (int a, int b) {
    // Arrange
    const a = 2;
    const b = 3;    

    // Act
    final answer = multiply(a, b);

    // Assert
    expect(answer, 6);
});

test('2 multiply -3 is equal to -6', (int a, int b) {
    // Arrange
    const a = 2;
    const b = -3;    

    // Act
    final answer = multiply(a, b);

    // Assert
    expect(answer, -6);
});

complex-multiply-test.md

test('a and b postive integer ...',(){..});

test('a and b negative integer ...',(){..});
test('a is positive and b is negative integer ...',(){..});
test('a is negative and b is positve integer ...',(){..});

test('a and b is 0 ...',(){..});
test('a or b is 0 ...',(){..});

test('a and b is 1 ...',(){..});
test('a or b is 1 ...',(){..});

...

complex-multiply.md

int multiply (int a, int b) {
    int sum = 0
    fot (int i = 0; i < b; i++) {
        sum += a;
    }
    return sum;
}