Invariants.java

1 
package com.renomad.minum.utils;
2
3 
/**
4 
 * Utilities for asserting invariants within the code.
5 
 * <br>
6 
 * The purpose here is to make firm statements about the code.  This is
7 
 * to help document the code, (e.g. at this point, x is the sum of the ...),
8 
 * to include testing mindset in the code, and to guard against adding
9 
 * bugs during maintenance.
10 
 */
11 
public final class Invariants {
12
13 
    private Invariants() {
14 
        // cannot construct
15 
    }
16
17 
    /**
18 
     * Specify something which must be true.
19 
     * <p>
20 
     * Throws an {@link InvariantException} if false
21 
     * @param predicate the boolean expression that must be true at this point
22 
     * @param message a message that will be included in the exception if this is false
23 
     */
24 
    public static void mustBeTrue(boolean predicate, String message) {
25 1 1. mustBeTrue : negated conditional → KILLED
 
        if (!predicate) {
26 
            throw new InvariantException(message);
27 
        }
28 
    }
29
30 
    /**
31 
     * Specify something which must be false
32 
     * <p>
33 
     * Throws an {@link InvariantException} if true
34 
     * @param predicate the boolean expression that must be false at this point
35 
     * @param message a message that will be included in the exception if this is true
36 
     */
37 
    public static void mustBeFalse(boolean predicate, String message) {
38 1 1. mustBeFalse : negated conditional → KILLED
 
        if (predicate) {
39 
            throw new InvariantException(message);
40 
        }
41 
    }
42
43 
    /**
44 
     * specifies that the parameter must be not null.
45 
     * <p>
46 
     * Throws an {@link InvariantException} if null.
47 
     * @return the object if not null
48 
     */
49 
    public static <T> T mustNotBeNull(T object) {
50 1 1. mustNotBeNull : negated conditional → KILLED
 
        if (object == null) {
51 
            throw new InvariantException("value must not be null");
52 
        } else {
53 1 1. mustNotBeNull : replaced return value with null for com/renomad/minum/utils/Invariants::mustNotBeNull → TIMED_OUT
 
            return object;
54 
        }
55 
    }
56 
}

Mutations

25

1.1
Location : mustBeTrue
Killed by : com.renomad.minum.utils.InvariantsTests.test_MustBeTrue(com.renomad.minum.utils.InvariantsTests) negated conditional → KILLED

38

1.1
Location : mustBeFalse
Killed by : com.renomad.minum.utils.InvariantsTests.test_MustBeFalse(com.renomad.minum.utils.InvariantsTests) negated conditional → KILLED

50

1.1
Location : mustNotBeNull
Killed by : com.renomad.minum.utils.InvariantsTests.test_MustNotBeNull(com.renomad.minum.utils.InvariantsTests) negated conditional → KILLED

53

1.1
Location : mustNotBeNull
Killed by : none replaced return value with null for com/renomad/minum/utils/Invariants::mustNotBeNull → TIMED_OUT

Active mutators

Tests examined


Report generated by PIT 1.17.0