Handle unbound wildcards and interactions with captured types better

[msridhar]

We correctly restore annotations from library models onto unbounded wildcard types, and the corresponding captured type variables. Add tests involving library models and also regular annotated source code, including a test with recursive bounds on the variables.

[msridhar]

This change is part of the following stack:

• Fix subtype checking for nested captured types #1663
  • Handle interaction of captured types and library models #1666
    • Follow-on fix for restoring annotation on captured type wildcards #1667
      • Harden TypeSubstitutionUtils type copies #1669
        • Handle unbound wildcards and interactions with captured types better #1668 ◀

_{Change managed by git-spice.}

[codecov]

Codecov Report

❌ Patch coverage is 70.00000% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.75%. Comparing base (6dd76de) to head (659a6b2).

Files with missing lines	Patch %	Lines
...librarymodel/AddAnnotationToNestedTypeVisitor.java	52.63%	9 Missing ⚠️

Additional details and impacted files

@@                      Coverage Diff                       @@
##             type-substitution-copies    #1668      +/-   ##
==============================================================
+ Coverage                       87.72%   87.75%   +0.02%     
- Complexity                       3145     3148       +3     
==============================================================
  Files                             109      109              
  Lines                           10691    10716      +25     
  Branches                         2159     2161       +2     
==============================================================
+ Hits                             9379     9404      +25     
- Misses                            623      626       +3     
+ Partials                          689      686       -3     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 2ff8d099-111b-4dda-9db2-308bb0609182

📥 Commits

Reviewing files that changed from the base of the PR and between 6dd76de and 659a6b2.

📒 Files selected for processing (5)

• nullaway/src/main/java/com/uber/nullaway/librarymodel/AddAnnotationToNestedTypeVisitor.java
• nullaway/src/test/java/com/uber/nullaway/jspecify/WildcardTests.java
• test-java-lib/src/main/java/com/uber/lib/unannotated/UnboundWildcards.java
• test-library-models/src/main/java/com/uber/nullaway/testlibrarymodels/TestLibraryModels.java
• test-library-models/src/test/java/com/uber/nullaway/CustomLibraryModelsTests.java

---

Walkthrough

The change updates AddAnnotationToNestedTypeVisitor to annotate implicit upper bounds for unbounded and captured wildcards while preserving lower-bound rejection and bounded wildcard behavior. It adds an UnboundWildcards<T> test library class and corresponding nullable library models. New JSpecify tests cover captured wildcard assignments, modeled nullable bounds, and F-bounded generic cache lookups.

Possibly related issues

• Further address issues involving captured types #1656 — Addresses the captured-type library-model gap by annotating captured unbounded wildcard bounds.

Possibly related PRs

• uber/NullAway#1407 — Introduced the visitor and wildcard library-model tests extended by this change.
• uber/NullAway#1615 — Modified wildcard-bound annotation handling in the same visitor.
• uber/NullAway#1666 — Added related captured and unbounded wildcard handling.

Suggested reviewers: lazaroclapp, yuxincs

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the changes to unbound wildcards and captured type interactions.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch unbound-wildcard-annotations

---

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.}