Add test for ancestor/descendant type-equality constraints

[cmarcelo]

Add a generics test that exercises equality constraints between nested types and their enclosing type:

• Box == Box.Nested
• Box.Nested == Box

[coderabbitai]

📝 Walkthrough

Walkthrough

A new test file is added to verify generic type equality constraints involving ancestor ordering. The test defines a generic struct with nested types and functions that enforce bidirectional type equality constraints, checking that expected constraint violations are properly detected.

Changes

Cohort / File(s)	Summary
Test Addition tests/language-feature/generics/type-equality-ancestor-ordering.slang	New test file for generic type equality constraints with ancestor ordering. Includes a generic Box<T> struct with nested Nested<U> type, two generic functions with opposing type equality constraints, and error validation.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 A box within a box so grand,
Where types must equal, carefully planned,
Ancestors checked in every way,
Generic constraints come to play!
Tests now dance to prove it's tight,
Type equality shines so bright! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: adding a test for ancestor/descendant type-equality constraints, which aligns with the new test file and its focus on type equality between nested types and their enclosing type.
Description check	✅ Passed	The description is directly related to the changeset, providing specific details about the equality constraints being tested: Box == Box.Nested and vice versa, which matches the test file content.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

🧹 Nitpick comments (1)

tests/language-feature/generics/type-equality-ancestor-ordering.slang (1)

23-24: Make the two expected failures distinguishable.

These two CHECK_FAIL-DAG lines are identical, so the test can pass without proving that triggerA<int>() and triggerB<int>() each failed independently. Please anchor each expectation to its specific instantiation site, or split the two directions into separate tests.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 14f298e9-d2e6-4e08-af80-1317b32a8eba

📥 Commits

Reviewing files that changed from the base of the PR and between d138e76 and fdab38b.

📒 Files selected for processing (1)

• tests/language-feature/generics/type-equality-ancestor-ordering.slang

[Copilot]

Pull request overview

Adds a new Slang generics regression test to ensure type-equality constraints behave consistently when comparing an enclosing generic type with a nested generic type, regardless of operand order.

Changes:

• Introduces a CHECK_FAIL-based test covering Box<X> == Box<X>.Nested<X> and the reversed constraint.
• Verifies both instantiations emit the expected diagnostic.

[aidanfnv]

Please update these checks to use the new diagnostics format. The format of these diagnostics has recently been changed, so these checks will now fail the CI tests until they are updated to the new format.

Please see https://github.com/shader-slang/slang/blob/master/docs/diagnostics.md for an explanation of the new format, and (more importantly for this case) https://github.com/shader-slang/slang/blob/master/docs/diagnostics.md#matching-fields for how to check the diagnostics in the new format.