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Sampling a property throws an error inside fast-check: "this.arb.withBias is not a function"

See original GitHub issue

🐛 Bug Report

I want to be able to change the assert function to a sample and see what values might be input into my test.

However, when I sample a property, I get the following error:

    TypeError: this.arb.withBias is not a function

      45 |
      46 | test('reproduction', () => {
    > 47 |   fc.sample(fc.property(fc.integer(), () => {})).forEach(console.log)
         |      ^
      48 | })
      49 |

      at ConverterToNext.generate (node_modules/fast-check/lib/check/arbitrary/definition/ConverterToNext.js:33:55)
      at Property.generate (node_modules/fast-check/lib/check/property/Property.generic.js:28:32)
      at node_modules/fast-check/lib/check/runner/Tosser.js:9:28
      at node_modules/fast-check/lib/check/runner/Sampler.js:26:62
      at mapHelper (node_modules/fast-check/lib/stream/StreamHelpers.js:19:15)
          at mapHelper.next (<anonymous>)
      at Object.sample (node_modules/fast-check/lib/check/runner/Sampler.js:33:16)
      at Object.<anonymous> (test/connectDisconnectModel.test.ts:47:6)

To Reproduce

fc.sample(fc.property(fc.integer(), () => {})).forEach(console.log)

Expected behavior

Doesn’t throw, prints out all the delicious generated parameters.

Your environment

Packages / Softwares	Version(s)
fast-check	2.22.0
node	16.3.0
TypeScript*	4.5.5

*Only for TypeScript’s users

Issue Analytics

State:
Created 2 years ago
Comments:5 (4 by maintainers)

Top GitHub Comments

1reaction

dubzzzcommented, Feb 19, 2022

Woups this is indeed not expected. Good catch 😱

0reactions

dubzzzcommented, May 31, 2022

Fixed in v3

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