[test] Move impl_or_verify! tests to doctests

[joshlf]

They require a lot of fragile machinery as UI tests, and are much
simpler as doc tests.

---

• 　  [test] Migrate from trybuild to ui-test #2986
• 👉 [test] Move impl_or_verify! tests to doctests #2988
• 　  [cargo-zerocopy] Pass RUSTDOCFLAGS #2987

Latest Update: v2 — Compare vs v1

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Branch

git fetch origin refs/heads/G793f61a136b912fbd5ee4315cdea7cf3cf3cf8fb && git checkout -b pr-G793f61a136b912fbd5ee4315cdea7cf3cf3cf8fb FETCH_HEAD

Checkout

git fetch origin refs/heads/G793f61a136b912fbd5ee4315cdea7cf3cf3cf8fb && git checkout FETCH_HEAD

Cherry Pick

git fetch origin refs/heads/G793f61a136b912fbd5ee4315cdea7cf3cf3cf8fb && git cherry-pick FETCH_HEAD

Pull

git pull origin refs/heads/G793f61a136b912fbd5ee4315cdea7cf3cf3cf8fb

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[gemini-code-assist]

Summary of Changes

Hello @joshlf, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request streamlines the testing infrastructure for the impl_or_verify! macro by transitioning its validation tests from traditional UI tests to Rust's built-in doctest system. This move significantly reduces the complexity and fragility associated with UI tests, resulting in a more robust and maintainable test suite.

Highlights

• Test Refactoring: The tests for the impl_or_verify! macro have been migrated from UI tests to Rust's built-in doctests.
• Simplified Testing: This change eliminates the need for complex UI test machinery, making the tests simpler, less fragile, and easier to maintain.
• Macro Export for Doctests: The impl_or_verify! macro is now conditionally exported using #[cfg_attr(__ZEROCOPY_INTERNAL_USE_ONLY_DEV_MODE, macro_export)] to allow its use within doctests.
• Removal of UI Test Files: Several UI test files and their corresponding stderr outputs, which previously handled invalid-impls scenarios, have been removed as their functionality is now covered by doctests.

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Changelog

• src/doctests.rs
  • Added a new compile_fail doctest, InvalidImplOrVerify, to validate the impl_or_verify! macro's behavior for invalid trait implementations.
• src/util/macros.rs
  • Applied #[cfg_attr(__ZEROCOPY_INTERNAL_USE_ONLY_DEV_MODE, macro_export)] to the impl_or_verify! macro, making it accessible for internal doctesting purposes.
  • Made a minor textual correction in a doc comment related to the impl_or_verify! macro's usage restrictions.
• tests/trybuild.rs
  • Removed the ui_invalid_impls test function, which previously managed the UI tests for invalid macro implementations.
• tests/ui-msrv/invalid-impls/invalid-impls.rs
  • Removed the UI test source file.
• tests/ui-msrv/invalid-impls/invalid-impls.stderr
  • Removed the expected error output file for the UI test.
• tests/ui-nightly/invalid-impls/invalid-impls.rs
  • Removed the UI test source file.
• tests/ui-nightly/invalid-impls/invalid-impls.stderr
  • Removed the expected error output file for the UI test.
• tests/ui-stable/invalid-impls/invalid-impls.rs
  • Removed the UI test source file.
• tests/ui-stable/invalid-impls/invalid-impls.stderr
  • Removed the expected error output file for the UI test.

Activity

• This pull request is part of a stacked series of changes, with references to [test] Migrate from trybuild to ui-test #2986, [test] Move impl_or_verify! tests to doctests #2988, and [cargo-zerocopy] Pass RUSTDOCFLAGS #2987, indicating a coordinated development effort.

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[gemini-code-assist]

Code Review

This pull request is a nice simplification of the test suite. It moves the tests for the impl_or_verify! macro from fragile trybuild UI tests into much simpler doctests. This refactoring correctly preserves the test's intent—ensuring that the macro fails to compile when trait bounds are missing—while significantly improving maintainability by removing the need for toolchain-specific test files. The changes are well-executed and I have no concerns.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.87%. Comparing base (5ed532f) to head (e5c4b11).

Additional details and impacted files

@@                            Coverage Diff                             @@
##           G413a86267ff4384a9806de9a784407f1f5be96aa    #2988   +/-   ##
==========================================================================
  Coverage                                      91.87%   91.87%           
==========================================================================
  Files                                             20       20           
  Lines                                           6057     6057           
==========================================================================
  Hits                                            5565     5565           
  Misses                                           492      492           

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