Add BeSupersetOf, BeProperSubsetOf and BeProperSupersetOf collection assertions - #3271
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Pull request overview
Adds new set-containment style collection assertions to FluentAssertions (BeSupersetOf, BeProperSubsetOf, BeProperSupersetOf) and factors shared subset/containment logic to reduce duplication, along with tests, docs, and updated API approval baselines.
Changes:
- Added
BeSupersetOf,BeProperSubsetOf, andBeProperSupersetOftoGenericCollectionAssertions. - Extracted shared helpers (
AssertSubsetOf,AssertContainment) and introducedConvertOrCastToSetfor set-based checks. - Added/ported specs and updated collection docs + release notes + API approval baselines.
Reviewed changes
Copilot reviewed 11 out of 12 changed files in this pull request and generated 4 comments.
Show a summary per file
| File | Description |
|---|---|
| Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeSupersetOf.cs | New specs covering BeSupersetOf success/failure and scope behavior. |
| Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeProperSupersetOf.cs | New specs covering BeProperSupersetOf, including equivalence and duplicates scenarios. |
| Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeProperSubsetOf.cs | New specs covering BeProperSubsetOf, including equivalence and null/empty scenarios. |
| Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt | API baseline updated for new assertions. |
| Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt | API baseline updated for new assertions. |
| Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt | API baseline updated for new assertions. |
| Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt | API baseline updated for new assertions. |
| Src/FluentAssertions/Common/EnumerableExtensions.cs | Adds internal ConvertOrCastToSet helper for set-based operations. |
| Src/FluentAssertions/Collections/GenericCollectionAssertions.cs | Implements the new assertions and refactors subset/containment logic into helpers. |
| docs/_pages/releases.md | Adds an “Unreleased” note about the new collection assertions. |
| docs/_pages/collections.md | Documents usage examples for the new assertions. |
| .gitignore | Fixes .junie/memory/ ignore entry and adds .nuke/temp. |
Suppressed comments (1)
Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeProperSupersetOf.cs:68
- Test name says "proper subset" but this spec is for
BeProperSupersetOf. Rename to "proper superset" to match the behavior under test.
public void A_collection_with_duplicates_is_not_a_proper_subset_of_another_with_duplicates()
…assertions Ports the work originally submitted in PR fluentassertions#2432 by @Meir017, adapted to the current AssertionChain-based assertion API. The original PR could not be reopened because its base branch (develop) no longer exists. - Add ConvertOrCastToSet extension to EnumerableExtensions - Extract AssertSubsetOf and AssertContainment helpers in GenericCollectionAssertions to share logic with the new assertions - Add BeSupersetOf, BeProperSubsetOf and BeProperSupersetOf methods - Add spec tests ported from the original PR - Update collections.md docs and releases.md Co-authored-by: Meir017 <Meir017@users.noreply.github.com> Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
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Pull request overview
Copilot reviewed 11 out of 12 changed files in this pull request and generated no new comments.
Suppressed comments (2)
Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeProperSubsetOf.cs:54
- This test name says the collection "has extra items", but the Arrange section is asserting that duplicates do not make a collection a proper subset when the distinct items are equivalent to the superset. Rename the test to describe equivalence rather than extra elements.
public void A_collection_with_all_items_and_duplicates_of_a_superset_but_has_extra_items_is_not_a_proper_subset()
Tests/FluentAssertions.Specs/Collections/CollectionAssertionSpecs.BeProperSubsetOf.cs:38
- This test name says the collection "has extra items", but the Arrange section uses two collections with the same distinct items (they're equivalent as sets). Rename the test to reflect that the failure is due to equivalence (not extra elements).
This issue also appears on line 54 of the same file.
public void A_collection_with_all_items_of_a_superset_but_has_extra_items_is_not_a_proper_subset()
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Ports the work originally submitted in #2432 by @Meir017 (
Meir017:feature/api-subset-and-superset), which added BeSupersetOf, BeProperSubsetOf and BeProperSupersetOf collection assertions.That PR could not be reopened because its base branch (develop) has since been deleted/renamed to main, so this PR recreates the same feature against current main.
What's included
Closes #2432
Resolves #2363
All credit for the original design and implementation goes to @Meir017.