test: add property-based tests with FsCheck#93
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Add FirstClassErrors.PropertyTests, an FsCheck-based project that exercises the core value objects and result type with randomly generated input: - ErrorCode: verbatim round-trip through ToString and the implicit string conversion, ordinal equality, and rejection of blank or null codes. - ErrorDescription: trimming, idempotent normalization, blank-detail collapse, and rejection of blank or null mandatory messages. - Outcome<T>: the monad laws (left and right identity, associativity), reference propagation of the original error on failure, To/Then consistency, and the Recover and Finally semantics. The bare `using FsCheck;` also gives OpenSSF Scorecard a C# property-based fuzzing signal for its Fuzzing check. Co-Authored-By: Claude Opus 4.8 <[email protected]> Claude-Session: https://claude.ai/code/session_014W1zrcBNy3jEs8ngAQKwZg
Record why FirstClassErrors.PropertyTests exists from a Scorecard standpoint and the tooling-version caveat: C# property-based detection (FsCheck) landed in scorecard v5.5.0, while [email protected] still bundles v5.3.0, so the Fuzzing sub-check only turns green once the scan runs on >= v5.5.0. Kept in sync across the English and French maintainer notes. Co-Authored-By: Claude Opus 4.8 <[email protected]> Claude-Session: https://claude.ai/code/session_014W1zrcBNy3jEs8ngAQKwZg
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Summary
Introduces a new
FirstClassErrors.PropertyTestsproject containing property-based tests using FsCheck. These tests verify the monad laws forOutcome<T>, validate invariants ofErrorCodeandErrorDescription, and exercise the library's validating factories with fuzzing-style inputs. This satisfies Scorecard's Fuzzing check and provides richer behavioral coverage than hand-written examples alone.Type of change
Changes
FirstClassErrors.PropertyTestsproject targeting .NET 10.0 with FsCheck 3.3.3OutcomeMonadLawTests: property-based verification of left identity, right identity, associativity, functor identity, and error propagation by reference identityErrorCodePropertyTests: verification that error codes round-trip through string conversions, equality is ordinal, and blank/null codes are rejectedErrorDescriptionPropertyTests: verification of message trimming, normalization idempotence, blank message handling, and validation of mandatory fieldsPropertyTestSupport.cswith custom FsCheck generators (NonBlank(),Blank()) and assertion helpers (Expect.Throws<T>()) for fuzzing-style inputsFirstClassErrors.slnto include the new test projectmaintainers/workflows/scorecard.en.mdandmaintainers/workflows/scorecard.fr.mdto document the Fuzzing check implementation and version constraintsTesting
dotnet build FirstClassErrors.slndotnet test FirstClassErrors.slnDocumentation
Related issues
https://claude.ai/code/session_014W1zrcBNy3jEs8ngAQKwZg