Rust: Add a type inference test case resembling PathBuf.canonicalize. #20222
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geoffw0
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Pull Request Overview
This PR adds a test case to demonstrate type inference limitations with the Deref trait in Rust, specifically testing a pattern resembling PathBuf.canonicalize() which is relevant to path injection analysis.
- Adds a simplified model of
PathandPathBuftypes withcanonicalizemethod - Implements
Dereftrait forPathBufto demonstrate implicit dereference behavior - Tests type inference through both direct method calls and calls via
Dereftrait
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| main.rs | Adds new path_buf module with test types and function demonstrating Deref trait limitations |
| type-inference.expected | Updates expected test output with new type inference results for the added test cases |
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Did you mean line 2601? |
hvitved
approved these changes
Aug 15, 2025
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Author
Yes. :) |
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Add a type inference test case resembling what I think happens in real world calls to
PathBuf.canonicalize, affecting the function of ourrust/path-injectionbarriersflow states. My understanding is that theDereftrait onPathBufmakes it behave much like a pointer to / slice of aPath, and type inference fails to work through what I believe is an implicit dereference on line 2597 of the test.The lack of support for the
Dereftrait is already a known problem, but I think it's good to have test coverage resembling real world patterns that matter to our analysis.@hvitved