Assertions.java

1 
package com.github.valid8j.classic;
2
3 
import com.github.valid8j.pcond.validator.Validator;
4
5 
import java.util.function.Predicate;
6
7 
/**
8 
 * // @formatter:off
9 
 * Use methods in this class with the ```assert``` statement.
10 
 *
11 
 * [source, java]
12 
 * ----
13 
 * import static com.github.valid8j.pcond.core.functions.Predicates.isNotNull;
14 
 * import static com.github.valid8j.pcond.classic.Assertions.*
15 
 *
16 
 * public class TestClass {
17 
 *   public static void aMethod(Object value) {
18 
 *     assert that(value, isNotNull());
19 
 *   }
20 
 * }
21 
 * ----
22 
 *
23 
 * This prints a much more readable error message than one you see for a usual assertion failure.
24 
 *
25 
 * ----
26 
 * Exception in thread "main" java.lang.AssertionError: Value:null violated: isNotNull
27 
 * null -> isNotNull -> false
28 
 * 	at com.github.valid8j.pcond.provider.impls.DefaultAssertionProvider.checkValue(DefaultAssertionProvider.java:70)
29 
 * 	at com.github.valid8j.pcond.provider.AssertionProviderBase.checkInvariant(AssertionProviderBase.java:78)
30 
 * 	at com.github.valid8j.pcond.classic.Assertions.that(Assertions.java:51)
31 
 * 	...
32 
 * ----
33 
 *
34 
 * To enable this feature, do not forget giving ```-ea``` VM option to enable assertions.
35 
 * Otherwise, the evaluation doesn't happen completely and even printable predicates constructed the right side of the `assert` statement.
36 
 * This means you can enable the feature during the development and disable it in the production so that you will not see no performance impact.
37 
 *
38 
 * // @formatter:on
39 
 *
40 
 */
41 
public enum Assertions {
42 
  ;
43 
  /**
44 
   * A method to be used for checking a value satisfies a given invariant condition.
45 
   * This method is intended to be used in `assert` statements.
46 
   *
47 
   * [source,java]
48 
   * .Example
49 
   * ----
50 
   * public void aMethod(String var) {
51 
   * assert that(var, isNotNull());
52 
   * }
53 
   * ----
54 
   *
55 
   * @param value     A value to be checked.
56 
   * @param predicate An invariant condition to check the {@code value}.
57 
   * @param <T>       The type of {@code value}.
58 
   * @return {@code true}, if the condition given as {@code predicate} is satisfied.
59 
   */
60 
  public static <T> boolean that(T value, Predicate<? super T> predicate) {
61 1 1. that : removed call to com/github/valid8j/pcond/validator/Validator::checkInvariant → KILLED
 
    Validator.instance().checkInvariant(value, predicate);
62 2 1. that : replaced boolean return with true for com/github/valid8j/classic/Assertions::that → SURVIVED
2. that : replaced boolean return with false for com/github/valid8j/classic/Assertions::that → KILLED
 
    return trueValue();
63 
  }
64
65 
  /**
66 
   * A method to be used for checking a value satisfies a given pre-condition.
67 
   * This method is intended to be used in `assert` statements.
68 
   *
69 
   * [source,java]
70 
   * .Example
71 
   * ----
72 
   * public void aMethod(String var) {
73 
   * assert precondition(var, isNotNull());
74 
   * }
75 
   * ----
76 
   *
77 
   * @param value     A value to be checked.
78 
   * @param predicate A pre-condition to check the {@code value}.
79 
   * @param <T>       The type of {@code value}.
80 
   * @return {@code true}, if the condition given as {@code predicate} is satisfied.
81 
   */
82 
  public static <T> boolean precondition(T value, Predicate<? super T> predicate) {
83 1 1. precondition : removed call to com/github/valid8j/pcond/validator/Validator::checkPrecondition → KILLED
 
    Validator.instance().checkPrecondition(value, predicate);
84 2 1. precondition : replaced boolean return with true for com/github/valid8j/classic/Assertions::precondition → SURVIVED
2. precondition : replaced boolean return with false for com/github/valid8j/classic/Assertions::precondition → KILLED
 
    return trueValue();
85 
  }
86
87 
  /**
88 
   * A method to be used for checking a value satisfies a given post-condition.
89 
   * This method is intended to be used in `assert` statements.
90 
   *
91 
   * [source,java]
92 
   * .Example
93 
   * ----
94 
   * public void aMethod(String var) {
95 
   * assert postcondition(var, isNotNull());
96 
   * }
97 
   * ----
98 
   *
99 
   * @param value     A value to be checked.
100 
   * @param predicate A post-condition to check the {@code value}.
101 
   * @param <T>       The type of {@code value}.
102 
   * @return {@code true}, if the condition given as {@code predicate} is satisfied.
103 
   */
104 
  public static <T> boolean postcondition(T value, Predicate<? super T> predicate) {
105 1 1. postcondition : removed call to com/github/valid8j/pcond/validator/Validator::checkPostcondition → KILLED
 
    Validator.instance().checkPostcondition(value, predicate);
106 2 1. postcondition : replaced boolean return with true for com/github/valid8j/classic/Assertions::postcondition → SURVIVED
2. postcondition : replaced boolean return with false for com/github/valid8j/classic/Assertions::postcondition → KILLED
 
    return trueValue();
107 
  }
108
109 
  /**
110 
   * This method always return {@code true}.
111 
   * This method is defined in order not to let an IDE report a warning
112 
   * Condition 'that(methodType, Predicates.isNotNull())' is always 'true'
113 
   * for caller codes of methods in this class.
114 
   *
115 
   * @return {@code true}
116 
   */
117 
  @SuppressWarnings("ConstantConditions")
118 
  private static boolean trueValue() {
119 2 1. trueValue : replaced boolean return with true for com/github/valid8j/classic/Assertions::trueValue → SURVIVED
2. trueValue : negated conditional → KILLED
 
    return Assertions.class != null;
120 
  }
121 
}

Mutations

61

1.1
Location : that
Killed by : com.github.valid8j.examples.test.ExamplesTest.testFluentExample(com.github.valid8j.examples.test.ExamplesTest) removed call to com/github/valid8j/pcond/validator/Validator::checkInvariant → KILLED
62

1.1
Location : that
Killed by : com.github.valid8j.entrypoints.AssertionsTest$MessageTest.givenLambda$whenPreconditionExercised_thenTrueReturned(com.github.valid8j.entrypoints.AssertionsTest$MessageTest) replaced boolean return with false for com/github/valid8j/classic/Assertions::that → KILLED

2.2
Location : that
Killed by : none replaced boolean return with true for com/github/valid8j/classic/Assertions::that → SURVIVED
83

1.1
Location : precondition
Killed by : com.github.valid8j.entrypoints.AssertionsTest$Failing removed call to com/github/valid8j/pcond/validator/Validator::checkPrecondition → KILLED
84

1.1
Location : precondition
Killed by : com.github.valid8j.ut.styles.FluentStyleDbCTest$ForEnsuresTest.test_precondition(com.github.valid8j.ut.styles.FluentStyleDbCTest$ForEnsuresTest) replaced boolean return with false for com/github/valid8j/classic/Assertions::precondition → KILLED

2.2
Location : precondition
Killed by : none replaced boolean return with true for com/github/valid8j/classic/Assertions::precondition → SURVIVED
105

1.1
Location : postcondition
Killed by : com.github.valid8j.entrypoints.AssertionsTest$Failing removed call to com/github/valid8j/pcond/validator/Validator::checkPostcondition → KILLED
106

1.1
Location : postcondition
Killed by : com.github.valid8j.ut.styles.FluentStyleDbCTest$ForEnsuresTest.test_postcondition(com.github.valid8j.ut.styles.FluentStyleDbCTest$ForEnsuresTest) replaced boolean return with false for com/github/valid8j/classic/Assertions::postcondition → KILLED

2.2
Location : postcondition
Killed by : none replaced boolean return with true for com/github/valid8j/classic/Assertions::postcondition → SURVIVED
119

1.1
Location : trueValue
Killed by : com.github.valid8j.entrypoints.AssertionsTest$MessageTest.givenLambda$whenPreconditionExercised_thenTrueReturned(com.github.valid8j.entrypoints.AssertionsTest$MessageTest) negated conditional → KILLED

2.2
Location : trueValue
Killed by : none replaced boolean return with true for com/github/valid8j/classic/Assertions::trueValue → SURVIVED

Active mutators

Tests examined


Report generated by PIT 1.7.3