[Austin Aviv (austinaviv)]

Description

Aligns OpenApiOperation.Tags setter and copy constructor with OpenApiDocument.Tags so that assigning
ull resets the tags property, and custom equality comparers or sorted sets are retained instead of being forced into OpenApiTagComparer.Instance.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Other (please describe):

Related Issue(s)

Fixes #3115

Changes Made

• Updated OpenApiOperation.Tags setter to assign _tags = null; when incoming value is null.
• Added pattern match in OpenApiOperation.Tags setter to preserve custom comparers, SortedSet, and ImmutableSortedSet (matching OpenApiDocument.Tags).
• Updated OpenApiOperation(OpenApiOperation operation) copy constructor to preserve custom comparers and sorted sets.
• Added unit tests covering reinitializing tags to null, preserving custom tag comparers, and sorted set handling.

Testing

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed
• All existing tests pass

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Versions applicability

• My change applies to the version 1.X of the library, if so PR link:
• My change applies to the version 2.X of the library, if so PR link:
• My change applies to the version 3.X of the library, if so PR link:
• I have evaluated the applicability of my change against the other versions above.

[Copilot]

🟡 Changes recommended

Immutable-set behavior lacks coverage, and the sorted-set test does not verify comparer preservation.

2 open findings

• Add operation tests for immutable sorted-set copying · New
• Use a distinguishable comparer to verify comparer preservation · New

What changed in this PR

Fixes operation tag resetting and preserves custom set semantics.

Changes:

• Allows resetting OpenApiOperation.Tags to null.
• Preserves custom comparers, sorted sets, and immutable sorted sets.
• Adds regression tests for most updated behaviors.

File	Description
src/​Microsoft.OpenApi/​Models/​OpenApiOperation.cs	Updates tag assignment and copying behavior.
test/​Microsoft.OpenApi.Tests/​Models/​OpenApiOperationTests.cs	Adds tag setter and copy-constructor tests.

🧠 Review effort: Balanced

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[Copilot]

🔵 Needs a closer look

The new immutable sorted-set assignment and copy paths lack test coverage.

1 open finding

• Add operation tests for immutable sorted-set copying

1 resolved since last review

• Use a distinguishable comparer to verify comparer preservation

🧠 Review effort: Balanced

[Copilot]

🟢 Approval recommended

Static review found no blocking issues, and regression tests cover the intended behavior; tests were not executed.

1 open issue

• Add operation tests for immutable sorted-set copying

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

The focused copy-constructor changes have regression coverage and no unresolved findings.

1 open issue

• Add operation tests for immutable sorted-set copying

_{Review effort: Balanced}

[Vincent Biret (baywet)]

Thank you for making the changes!

[Copilot]

🟢 Approval recommended

The focused changes preserve existing setter behavior and cover the corrected copying behavior with regression tests.

1 open issue

• Add operation tests for immutable sorted-set copying

_{Review effort: Balanced}

[Vincent Biret (baywet)]

Thanks for the contribution!