npmpackage.info

Gathering detailed insights and metrics for fast-check

Other packages similar to fast-check

@fast-check/ava

2.0.2

Property based testing for AVA based on fast-check

fast-isnumeric

1.1.4

The fast way to check if a JS object is numeric

@fast-check/jest

2.1.1

Property based testing for Jest based on fast-check

@fast-check/vitest

0.2.1

Property based testing for Vitest based on fast-check

Gathering detailed insights and metrics for fast-check

fast-check - 4.2.0 | npmpackage.info

fast-check

Property based testing framework for JavaScript (like QuickCheck) written in TypeScript

4.2.0

4,559

MIT

TypeScript

46.65 kB

131,159,154 8.1

Installations

npm install fast-check

Developer Guide

BETA

Typescript

Yes

Module System

ESM

Min. Node Version

>=12.17.0

Node Version

22.17.0

NPM Version

10.9.2 Score

99.7

Supply Chain

100

Quality

88.6

Maintenance

100

Vulnerability

100

License

Pull Requests

Open

9

Total

5,384

Closed

279

Merged

5,096

Issues

Open

43

Total

576

Closed

533

Releases

257

New primitives for race condition detection

v4.2.0

Updated on Jul 05, 2025

Forward errors properly when using fast-check v3

vitest/v0.2.1

Updated on Apr 11, 2025

Avoid overlapping tasks

v4.1.1

Updated on Apr 08, 2025

More effective `waitFor` on `fc.scheduler`

v4.1.0

Updated on Apr 05, 2025

Support for most recent version of `@fast-check/worker`

jest/v2.1.1

Updated on Mar 28, 2025

Change location of the logo on the README for LFS quotas reasons

v4.0.1

Updated on Mar 28, 2025

View All 257 releases

Languages

TypeScript

JavaScript

MDX

CSS

Shell

TypeScript (93.53%)

JavaScript (5.01%)

MDX (1.02%)

CSS (0.43%)

Shell (0.01%)

Developer

dubzzz

Download Statistics

Total Downloads

131,159,154

Last Day

111,597

Last Week

2,051,086

Last Month

9,214,115

Last Year

93,511,923

GitHub Statistics

MIT License

4,559 Stars

5,889 Commits

190 Forks

19 Watchers

13 Branches

73 Contributors

Updated on Jul 05, 2025

Bundle Size

153.54 kB

Minified

46.65 kB

Minified + Gzipped

Bundlephobia

Sponsor this package

https://github.com/sponsors/dubzzz https://opencollective.com/fast-check

Maintainers

View All 73 Contributors

Package Meta Information

Latest Version

4.2.0

Package Id

fast-check@4.2.0

Unpacked Size

1.47 MB

Size

186.11 kB

File Count

1,277

NPM Version

10.9.2

Node Version

22.17.0

Published on

Jul 05, 2025

Total Downloads

Cumulative downloads

Total Downloads

131,159,154

Last Day

10.2%

111,597

Compared to previous day

Last Week

-10.4%

2,051,086

Compared to previous week

Last Month

2.3%

9,214,115

Compared to previous month

Last Year

370.9%

93,511,923

Compared to previous year

Weekly Downloads

Monthly Downloads

Yearly Downloads

Dependencies

pure-rand

Dev Dependencies

@microsoft/api-extractor @types/node cross-env glob not-node-buffer regexp-tree replace-in-file typedoc typescript vitest @fast-check/expect-type @fast-check/poisoning fast-check

Property based testing framework for JavaScript/TypeScript

Getting started

Hands-on tutorial and definition of Property Based Testing: 🏁 see tutorial. Or directly try it online on our pre-configured CodeSandbox.

Property based testing frameworks check the truthfulness of properties. A property is a statement like: for all (x, y, ...) such that precondition(x, y, ...) holds predicate(x, y, ...) is true.

Install the module with: pnpm add -D fast-check or yarn add fast-check --dev or npm install fast-check --save-dev

Example of integration in mocha:

1import fc from 'fast-check';
2
3// Code under test
4const contains = (text, pattern) => text.indexOf(pattern) >= 0;
5
6// Properties
7describe('properties', () => {
8  // string text always contains itself
9  it('should always contain itself', () => {
10    fc.assert(fc.property(fc.string(), (text) => contains(text, text)));
11  });
12  // string a + b + c always contains b, whatever the values of a, b and c
13  it('should always contain its substrings', () => {
14    fc.assert(
15      fc.property(fc.string(), fc.string(), fc.string(), (a, b, c) => {
16        // Alternatively: no return statement and direct usage of expect or assert
17        return contains(a + b + c, b);
18      }),
19    );
20  });
21});

In case of failure, the test raises a red flag. Its output should help you to diagnose what went wrong in your implementation. Example with a failing implementation of contain:

1) should always contain its substrings
    Error: Property failed after 1 tests (seed: 1527422598337, path: 0:0): ["","",""]
    Shrunk 1 time(s)
    Got error: Property failed by returning false

    Hint: Enable verbose mode in order to have the list of all failing values encountered during the run

Integration with other test frameworks: ava, jasmine, jest, mocha and tape.

More examples: simple examples, fuzzing and against various algorithms.

Useful documentations:

Why should I migrate to fast-check?

fast-check has initially been designed in an attempt to cope with limitations I encountered while using other property based testing frameworks designed for JavaScript:

Types: strong and up-to-date types - thanks to TypeScript
Extendable: easy map method to derive existing arbitraries while keeping shrink [more] - some frameworks ask the user to provide both a->b and b->a mappings in order to keep a shrinker
Extendable: kind of flatMap-operation called chain [more] - able to bind the output of an arbitrary as input of another one while keeping the shrink working
Extendable: precondition checks with fc.pre(...) [more] - filtering invalid entries can be done directly inside the check function if needed
Extendable: easily switch from fake data in tests to property based with fc.gen() [more] - generate random values within your predicates
Smart: ability to shrink on fc.oneof [more] - surprisingly some frameworks don't
Smart: biased by default - by default it generates both small and large values, making it easier to dig into counterexamples without having to tweak a size parameter manually
Debug: verbose mode [more][tutorial] - easier troubleshooting with verbose mode enabled
Debug: replay directly on the minimal counterexample [tutorial] - no need to replay the whole sequence, you get directly the counterexample
Debug: custom examples in addition of generated ones [more] - no need to duplicate the code to play the property on custom examples
Debug: logger per predicate run [more] - simplify your troubleshoot with fc.context and its logging feature
Unique: model based approach [more][article] - use the power of property based testing to test UI, APIs or state machines
Unique: detect race conditions in your code [more][tutorial] - shuffle the way your promises and async calls resolve using the power of property based testing to detect races
Unique: simplify user definable corner cases [more] - simplify bug resolution by asking fast-check if it can find an even simpler corner case

For more details, refer to the documentation in the links above.

Trusted

fast-check has been trusted for years by big projects like: jest, jasmine, fp-ts, io-ts, ramda, js-yaml, query-string...

Powerful

It also proved useful in finding bugs among major open source projects such as jest, query-string... and many others.

Compatibility

Here are the minimal requirements to use fast-check properly without any polyfills:

fast-check	node	ECMAScript version	TypeScript (optional)
4.x	≥12.17.0⁽¹⁾	ES2020	≥5.0
3.x	≥8⁽²⁾	ES2017	≥4.1⁽³⁾
2.x	≥8⁽²⁾	ES2017	≥3.2⁽⁴⁾
1.x	≥0.12⁽²⁾	ES3	≥3.0⁽⁴⁾

More details...

Even if version 12.x should support most of the ES2020 features that will be leveraged by the version 4, we recommend relying at least on version 14.x of Node as it supports all the targeted specification. In addition, we highly encourage switching to still supported LTS versions of Node and not sticking to unsupported versions for too long.
Except for features that cannot be polyfilled - such as bigint-related ones - all the capabilities of fast-check should be usable given you use at least the minimal recommended version of node associated to your major of fast-check.
Require either lib or target ≥ ES2020 or @types/node to be installed.
Require either lib or target ≥ ES2015 or @types/node to be installed.

Contributors ✨

Thanks goes to these wonderful people (emoji key):

_{Nicolas DUBIEN} 💻 📖 ⚠️ 🚇 🎨 🚧	_{Aaron Elligsen} 💻 📖 ⚠️	_{Will Heslam} 📖	_kazchimo 💻 📖	_{Brandon Chinn} 💻 📖	_{Irakli Safareli} 📖	_{Andrew Herron} 📖 🔌
_{Eric Crosson} 📖 💻	_burrscurr 📖	_{JC (Jonathan Chen)} 📖	_{Larry Botha} 📖 💻 ⚠️	_{Roman Gusev} 📖	_{Tim Wisniewski} 📖	_{Brais Piñeiro} 💻 ⚠️
_{Renaud-Pierre Bordes} 🎨	_{Jemma Nelson} 📖	_{John Haugeland} 📖	_{Trey Davis} 🎨	_{Leon Si} 📖	_{Gorgi Kosev} 🚇	_mayconsacht 💻
_{Simon Friis Vindum} 💻 ⚠️	_{Richard Gibson} 📖	_{Alan Harper} 📖	_{Makien Osman} 💻	_{David Sommerich} 💻 ⚠️	_{Diego Pedro} 💻 ⚠️	_{Borui Gu} 📖
_{Brian Donovan} 📖	_volrk 💻 📖 ⚠️	_tinydylan 💻 ⚠️	_{Caleb Jasik} 📖	_{Rulai Hu} 📖	_{Afonso Jorge Ramos} 📖	_{Tom Jenkinson} 📖
_phormio 📖	_{Giovanni Gonzaga} 💻 ⚠️	_{Tomas Carnecky} 💻	_{Kirill Romanov} 💻 📖 ⚠️	_{Giovanny González} 📖	_{Mark Kulube} 🚇	_{Peter Hamilton} 💻
_{Chinedu Ozodi} 📖	_{Gunar Gessner} 📖	_{Christian Batchelor} ⚠️	_{Tomer Aberbach} 💻 📖 ⚠️	_0xflotus 📖	_{Ryan Leonard} 💻 📖 ⚠️	_{Jason Dreyzehner} 💻 ⚠️
_{Matin Zadeh Dolatabad} 💻	_{Juan Julián Merelo Guervós} 📖	_{Simen Bekkhus} 📖	_{Tarjei Skjærset} 📖	_{Denis Gorbachev} 📖	_{Trevor McCauley} 📖	_{Grant Kiely} 📖
_{Attila Večerek} 💻 📖 ⚠️	_{Zach Bjornson} 💻 📖	_{Bennett Perkins} 📖	_{Alexandre Oger} 📖	_{ej shafran} 📖	_{Niklas Gruhn} 💻 💬	_{Patrick Roza} 💻
_{Cindy Wu} 📖	_Noah 📖	_{James Vaughan} 📖	_{Alex Errant} 💻	_{andrew jarrett} 💻	_{Matthias Keckl} 📖

This project follows the all-contributors specification. Contributions of any kind welcome! Become one of them

Sponsors 💸

Many individuals and companies offer their financial support to the project, a huge thanks to all of them too 💓

You can also become one of them by contributing via GitHub Sponsors or OpenCollective.

No vulnerabilities found.

10

Maintained

Determines if the project is "actively maintained".

10

Dependency-Update-Tool

Determines if the project uses a dependency update tool.

10

Security-Policy

Determines if the project has published a security policy.

10

Dangerous-Workflow

Determines if the project's GitHub Action workflows avoid dangerous patterns.

10

Binary-Artifacts

Determines if the project has generated executable (binary) artifacts in the source repository.

10

Token-Permissions

Determines if the project's workflows follow the principle of least privilege.

10

Pinned-Dependencies

Determines if the project has declared and pinned the dependencies of its build process.

10

SAST

Determines if the project uses static code analysis.

10

License

Determines if the project has defined a license.

10

Packaging

Determines if the project is published as a package that others can easily download, install, easily update, and uninstall.

10

Fuzzing

Determines if the project uses fuzzing.

Reason

project is fuzzed

Details

Info: TypeScriptPropertyBasedTesting integration found: examples/001-simple/decompPrime/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/001-simple/fibonacci/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/001-simple/indexOf/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/001-simple/sort/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/002-recursive/isSearchTree/arbitraries/BinarySearchTreeArbitrary.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/002-recursive/isSearchTree/arbitraries/BinaryTreeArbitrary.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/002-recursive/isSearchTree/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/003-misc/knight/arbitraries/SpaceArbitrary.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/003-misc/knight/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/003-misc/mazeGenerator/main.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: examples/003-misc/mazeGenerator/src/mazeGenerator.ts:3
Info: TypeScriptPropertyBasedTesting integration found: examples/003-misc/roman/main.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: examples/004-stateMachine/musicPlayer/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/004-stateMachine/musicPlayer/model-based/MusicPlayerCommands.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/004-stateMachine/musicPlayer/model-based/MusicPlayerModel.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/005-race/counter/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/005-race/dependencyTree/main.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: examples/005-race/supertest/app.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: examples/005-race/todolist/model-based/Model.ts:1
Info: TypeScriptPropertyBasedTesting integration found: examples/vitest.setup.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/ava/src/ava-fast-check.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/ava/test-types/main.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test-types/main.ts:5
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/e2e/Bundle.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/e2e/seed.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/__test-helpers__/ArbitraryAssertions.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/__test-helpers__/FloatingPointHelpers.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/__test-helpers__/ShrinkTree.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/__test-helpers__/SizeHelpers.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/__test-helpers__/SpyCleaner.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/AdapterArbitrary.spec.ts:8
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/ArrayArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/BigIntArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/CloneArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/ConstantArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/FrequencyArbitrary.part1.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/FrequencyArbitrary.part2.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/IntegerArbitrary.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/LimitedShrinkArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/MixedCaseArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/StreamArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/SubarrayArbitrary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/WithShrinkFromOtherArbitrary.spec.ts:7
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/builders/AnyArbitraryBuilder.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/builders/TypedIntArrayArbitraryBuilder.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/BiasNumericRange.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/CustomEqualSet.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/DoubleHelpers.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/DoubleOnlyHelpers.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/FloatHelpers.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/GraphemeRangesHelpers.spec.ts:7
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/InvalidSubdomainLabelFiIter.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/MaxLengthFromMinLength.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/SameValueSet.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/SameValueZeroSet.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/ShrinkBigInt.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/ShrinkInteger.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/StrictlyEqualSet.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/TextEscaper.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/ToggleFlags.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/helpers/ZipIterableIterators.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/implementations/SchedulerImplem.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/implementations/SlicedBasedGenerator.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/CharsToString.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/CodePointsToString.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/NatToStringifiedNat.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/NumberToPaddedEight.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/PaddedEightsToUuid.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/PartsToUrl.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/PatternsToString.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/SegmentsToPath.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/TimeToDate.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/UintToBase32String.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/UnboxedToBoxed.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/VersionsApplierForUuid.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/_internals/mappers/WordsToLorem.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/array.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/base64String.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/bigInt.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/commands.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/compareBooleanFunc.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/compareFunc.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/constant.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/constantFrom.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/date.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/dictionary.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/domain.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/double.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/emailAddress.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/float.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/float32Array.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/float64Array.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/func.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/integer.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/jsonValue.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/lorem.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/mapToConstant.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/nat.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/oneof.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/option.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/record.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/sparseArray.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/string.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/stringMatching.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/uniqueArray.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/uuid.spec.ts:5
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/webAuthority.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/webPath.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/arbitrary/webUrl.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/model/ModelRunner.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/model/ReplayPath.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/model/commands/CommandsIterable.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/precondition/Pre.spec.ts:4
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/property/AsyncProperty.spec.ts:14
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/property/Property.spec.ts:14
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/Runner.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/Sampler.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/SourceValuesIterator.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/Tosser.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/configuration/GlobalParameters.spec.ts:7
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/configuration/QualifiedParameters.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/runner/reporter/RunExecution.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/check/symbols.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/random/generator/Random.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/utils/hash.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/fast-check/test/unit/utils/stringify.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/internals/TestBuilder.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/internals/TestBuilder.ts:4
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/internals/TestWithPropRunnerBuilder.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/internals/TestWithPropRunnerBuilder.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/internals/types.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/jest-fast-check-worker.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/src/jest-fast-check.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test-types/main.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test/jest-fast-check.spec.ts:7
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test/jest-fast-check.spec.ts:8
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test/jest-fast-check.spec.ts:597
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test/jest-fast-check.spec.ts:599
Info: TypeScriptPropertyBasedTesting integration found: packages/jest/test/types.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestAlongGenerator.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestAlongGenerator.ts:6
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestBuilder.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestBuilder.ts:4
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestWithPropRunnerBuilder.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/TestWithPropRunnerBuilder.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/internals/types.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/src/vitest-fast-check.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/test-types/main.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/test/vitest-fast-check.spec.ts:12
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/test/vitest-fast-check.spec.ts:13
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/test/vitest-fast-check.spec.ts:287
Info: TypeScriptPropertyBasedTesting integration found: packages/vitest/test/vitest-fast-check.spec.ts:290
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/MainThreadRunner.ts:8
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/SharedTypes.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/ValueFromState.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/ValueFromState.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-property/NoopWorkerProperty.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-property/WorkerPropertyBuilder.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-property/WorkerPropertyBuilder.ts:5
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-property/WorkerPropertyFromWorker.ts:10
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-property/WorkerPropertyFromWorker.ts:15
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/internals/worker-runner/WorkerRunner.ts:5
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/main.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/src/main.ts:4
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test-types/main.ts:1
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/asyncThrow.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/blockEventLoop.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/concurrentAssert.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/failing.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/noWorker.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/nonSerializableButSameData.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/nonSerializableButSameData.spec.ts:3
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/nonSerializableData.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/passing.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/predicateIsolation.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/propertyIsolation.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/supportPre.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/syncThrow.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/e2e/unregistered.spec.ts:2
Info: TypeScriptPropertyBasedTesting integration found: packages/worker/test/internals/worker-property/WorkerPropertyFromWorker.spec.ts:2

10

CI-Tests

Determines if the project runs tests before pull requests are merged.

6

Contributors

Determines if the project has a set of contributors from multiple organizations (e.g., companies).

5

CII-Best-Practices

Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.

4

Vulnerabilities

Determines if the project has open, known unfixed vulnerabilities.

3

Branch-Protection

Determines if the default and release branches are protected with GitHub's branch protection settings.

1

Code-Review

Determines if the project requires human code review before pull requests (aka merge requests) are merged.

Score

8.1

/10

Last Scanned on 2025-07-07T18:48:49Z

The Open Source Security Foundation is a cross-industry collaboration to improve the security of open source software (OSS). The Scorecard provides security health metrics for open source projects.

Learn More