https://github.com/dubzzz/fast-spec

Discover laws in your code like with QuickSpec
https://github.com/dubzzz/fast-spec

fast-check laws quickspec

Last synced: 2 months ago
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Discover laws in your code like with QuickSpec

• Host: GitHub
• URL: https://github.com/dubzzz/fast-spec
• Owner: dubzzz
• License: mit
• Created: 2019-10-17T17:35:12.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2021-06-06T15:38:36.000Z (over 3 years ago)
• Last Synced: 2024-08-11T10:49:27.777Z (4 months ago)
• Topics: fast-check, laws, quickspec
• Language: TypeScript
• Homepage:
• Size: 86.9 KB
• Stars: 14
• Watchers: 3
• Forks: 1
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# fast-spec

Discover laws in your code like with QuickSpec

## In a nutshell

Have you ever wondered what could be the laws that rule your code? The complex relations there might be between two distinct functions?

`fast-spec` is able to help you discover them.

## Example

Let's find the laws that link `concat`, `reverse` and `[]` together.

```js

import * as fc from "fast-check";

import { funcDef, instDef, varDef, findSpecs } from "fast-spec";

// const fc = require("fast-check");

// const { funcDef, instDef, varDef, findSpecs } = require("fast-spec");

findSpecs([

  // declare functions to be considered

  funcDef("concat", 2, (a, b) => [...a, ...b]),

  funcDef("reverse", 1, (a) => [...a].reverse()),

  // declare basic root values (of special interest)

  instDef("[]", []),

  // declare complex values that can be consumed by your functions

  varDef("x", fc.array(fc.char()))

], { // optional settings

  // number of combinations to try - default: 100

  numSamples: 100,

  // complexity of the combinations - default: 2

  complexity: 2,

  // number of inputs to try to confirm a combination - default: 100

  numFuzz: 100

})

```

`fast-spec` will be able to find relationships like:

- concat([], []) = []

- concat([], x0) == x0

- concat(x0, []) == x0

- concat(concat(x0, x1), x2) == concat(x0, concat(x1, x2))

- concat(reverse(x0), reverse(x1)) == reverse(concat(x1, x0))

- reverse([]) = []

- reverse(reverse(x0)) == x0

- ...

*Live example available at https://runkit.com/dubzzz/hello-world-fast-spec-v2*