testland/jqwik-testing

Authors property-based tests for the JVM (Java + Kotlin) using jqwik - wires `@Property` test methods, `@ForAll` parameter annotations, `Arbitraries.integers/strings/etc` generators, custom `@Provide` arbitraries, and the JUnit 5 platform integration. Use when a JVM project needs PBT - alternative to JUnit-QuickCheck and Vavr's property-checking; tightly integrates with JUnit 5 so property tests run alongside conventional unit tests in the same Maven / Gradle pipeline.

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jqwik reference

Name: testland/jqwik-testing
Rating: 75.2 (1 reviews)
Author: testland

Full lookup tables and maintenance notes for jqwik-testing. Source: jqwik.net.

Version

Pinned to jqwik 1.9.3 (latest at source-fetch); the artifact pulls in the JUnit 5 platform dependency transitively. Check jqwik.net before bumping.

Constraint annotations

In net.jqwik.api.constraints.*:

Annotation	Purpose
`@IntRange(min, max)`	Integers in range
`@LongRange(min, max)`	Longs in range
`@DoubleRange(min, max)`	Doubles in range
`@StringLength(min, max)`	Strings of bounded length
`@AlphaChars` / `@NumericChars`	String character class
`@Size(min, max)`	Collection size
`@NotEmpty`	Non-empty collection / string
`@NotBlank`	Non-whitespace string
`@Email`	Email-shaped string
`@MinList` / `@MaxList`	List bounds
`@UniqueElements`	Unique-element collections
`@Positive` / `@Negative`	Positive / negative number

Arbitraries catalog

Arbitraries.integers()                       // any int
    .between(0, 100)                         // bounded
    .greaterOrEqual(0);                       // half-bounded

Arbitraries.strings()                        // any string
    .alpha()                                  // alphabetic only
    .ofLength(8);                             // fixed length

Arbitraries.of(Status.ACTIVE, Status.SUSPENDED, Status.NOT_VERIFIED);   // enum-like

Arbitraries.subsetOf(allRoles);              // subset of a known set

For collections:

Arbitraries.integers().list()                // List<Integer>
    .ofMinSize(1).ofMaxSize(100);

Arbitraries.strings().set();                  // Set<String>

Arbitraries.maps(
    Arbitraries.strings().alpha(),
    Arbitraries.integers().between(0, 100)
);

Anti-patterns

Anti-pattern	Why it fails	Fix
Returning `void` without assertions	Test always passes; property is silent.	Return `boolean` OR throw on failure (e.g. JUnit `assertTrue`).
`@Provide` arbitrary that filters most cases	Discard ratio exceeded; jqwik fails the property.	Constrain at the Arbitrary level (Step 3 annotations + `.between(...)`).
Sharing mutable state across @Property iterations	Test depends on iteration order; flaky.	Construct fresh state per call (within the property method body).
Hard-coded seed in production property	Loses randomization; misses regressions.	Random seed locally; fixed seed in CI only (Step 7).
`tries = 100_000` on a slow property	CI never finishes.	Budget per `total runtime / tries`.
Asserting on specific values inside the property	Defeats PBT.	Properties assert relationships.
Skipping `@Provide` for one-off domain objects	Inline construction is verbose; harder to reuse.	Move to `@Provide` even for one-property arbitraries.

Limitations

JVM startup cost. Each property test pays JVM start; 1000 iterations of fast tests are still seconds, not milliseconds.
Shrinking complex types is slow. BOUNDED shrinking caps iterations; OFF skips entirely.
Kotlin support requires extra setup. Per jqwik.net, Kotlin is supported but requires the jqwik-kotlin extension.
No native async support. Test reactive / coroutine code through runBlocking (Kotlin) or explicit Future.get().
JUnit 5 only. No JUnit 4 platform integration.

.tessl-plugin

references

jqwik-reference.md

SKILL.md

tile.json