https://github.com/pholser/junit-quickcheck

Property-based testing, JUnit-style
https://github.com/pholser/junit-quickcheck

java junit property-based-testing quickcheck

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Property-based testing, JUnit-style

• Host: GitHub
• URL: https://github.com/pholser/junit-quickcheck
• Owner: pholser
• License: mit
• Created: 2010-10-18T22:33:36.000Z (about 14 years ago)
• Default Branch: master
• Last Pushed: 2024-04-15T12:34:10.000Z (7 months ago)
• Last Synced: 2024-04-16T10:23:25.913Z (7 months ago)
• Topics: java, junit, property-based-testing, quickcheck
• Language: Java
• Homepage:
• Size: 17.4 MB
• Stars: 952
• Watchers: 35
• Forks: 122
• Open Issues: 36
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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# junit-quickcheck: Property-based testing, JUnit-style

junit-quickcheck is a library that supports writing and running property-based

tests in JUnit, inspired by QuickCheck for Haskell.

Property-based tests capture characteristics, or "properties", of the output

of code that should be true given arbitrary inputs that meet certain criteria.

For example, imagine a function that produces a list of the prime factors of

a positive integer `n` greater than 1. Regardless of the specific value of

`n`, the function must give a list whose members are all primes, must

equal `n` when all multiplied together, and must be different from the

factorization of a positive integer `m` greater than 1 and not equal to

`n`.

Rather than testing such properties for all possible inputs, junit-quickcheck

and other QuickCheck kin generate some number of random inputs, and verify

that the properties hold at least for the generated inputs. This gives us

some reasonable assurance upon repeated test runs that the properties

hold true for any valid inputs.

## Documentation

[Documentation for the current stable version](https://pholser.github.io/junit-quickcheck/index.html)

## Basic example

```java

    import com.pholser.junit.quickcheck.Property;

    import com.pholser.junit.quickcheck.runner.JUnitQuickcheck;

    import org.junit.runner.RunWith;

    import static org.junit.Assert.*;

    @RunWith(JUnitQuickcheck.class)

    public class StringProperties {

        @Property public void concatenationLength(String s1, String s2) {

            assertEquals(s1.length() + s2.length(), (s1 + s2).length());

        }

    }

```

## Other examples

After browsing the [documentation](#documentation), have a look at some

[examples](examples) in module `junit-quickcheck-examples`. These are built

with junit-quickcheck.