✨ Attach the original Error as a cause of thrown one

[dubzzz]

Category:

• ✨ Introduce new features
• 📝 Add or update documentation
• ✅ Add or update tests
• 🐛 Fix a bug
• 🏷️ Add or update types
• ⚡️ Improve performance
• Other(s): ...

Potential impacts:

• Generated values
• Shrink values
• Performance
• Typings
• Other(s): ...

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 6e21c90:

Sandbox	Source
Vanilla	Configuration
@fast-check/examples	Configuration

[codecov]

Codecov Report

Merging #2965 (5307918) into main (0ab23c5) will decrease coverage by 0.09%.
The diff coverage is 66.66%.

❗ Current head 5307918 differs from pull request most recent head 6e21c90. Consider uploading reports for the commit 6e21c90 to get more accurate results

@@            Coverage Diff             @@
##             main    #2965      +/-   ##
==========================================
- Coverage   95.58%   95.48%   -0.10%     
==========================================
  Files         212      212              
  Lines        5815     5828      +13     
  Branches     1072     1075       +3     
==========================================
+ Hits         5558     5565       +7     
- Misses        257      263       +6     

Flag	Coverage Δ
unit-tests	95.48% <66.66%> (-0.10%)	⬇️
unit-tests-14.x-Linux	95.45% <66.66%> (-0.10%)	⬇️
unit-tests-16.x-Linux	95.48% <66.66%> (-0.08%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...check/src/check/runner/configuration/Parameters.ts	0.00% <ø> (ø)
...heck/src/check/runner/utils/RunDetailsFormatter.ts	63.56% <33.33%> (-0.85%)	⬇️
.../check/runner/configuration/QualifiedParameters.ts	97.56% <100.00%> (+0.06%)	⬆️
packages/fast-check/src/arbitrary/unicode.ts	94.44% <0.00%> (-5.56%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[dubzzz]

Waiting the end of my work on 'better handling of poisoning' before reliving this PR. In order not to break the existing users, the error with cause will be provided as an opt-in option. Helpers around test runners (not any for vitest yet but will come) will probably enforce it according to how well the test runner handle them.

[jasikpark]

This will be nice so I can stop using:

fc.context(), (input, ctx) => {  ctx.log(`input: ${input}, output: ${functionUnderTest(input)}`); }

in my property tests

[dubzzz]

Interested to now why you need this pattern? By the way, you can override the default error reporter if needed

[jasikpark]

I have a pretty similar goal to #660 i think - I want to see the expected vs actual values on jest expect errors in vitest

[dubzzz]

ava 4.3.3 🔴

jasmine 4.4.0 🔴

jest 28.1.2 🔴

mocha 10.0.0 🔴

node 16.14.0 🟢

vitest 0.17.0 🟢

[dubzzz]

please deploy

[github-actions]

Give a try to 5307918 with:

yarn add https://632a07884ff4a50bae9af377--dazzling-goodall-4f0e38.netlify.app/fast-check.tgz
npm i https://632a07884ff4a50bae9af377--dazzling-goodall-4f0e38.netlify.app/fast-check.tgz

Or have a look to the generated documentation.

[dubzzz]

With the new flag against vitest:

Code snippet

import { test, expect } from "vitest";
import fc from "fast-check";

fc.configureGlobal({ errorWithCause: true });

test("error cause", () => {
  fc.assert(
    fc.property(fc.integer(), (n) => {
      return n <= 10;
    })
  );
});

test("error cause (expect)", () => {
  fc.assert(
    fc.property(fc.integer(), (n) => {
      expect(n).toBeLessThanOrEqual(10);
    })
  );
});

With the flag against node:

Code snippet 1

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

fc.configureGlobal({ errorWithCause: true });

fc.assert(
  fc.property(fc.integer(), (n) => {
    return n <= 10;
  })
);

Code snippet 2

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

fc.configureGlobal({ errorWithCause: true });

fc.assert(
  fc.property(fc.integer(), (n) => {
    assert(n <= 10);
  })
);